Smith & Wesson Forum

Go Back   Smith & Wesson Forum > Ammunition-Gunsmithing > S&W-Smithing
o

Notices

S&W-Smithing Maintenance, Repair, and Enhancement of Smith & Wesson and Other Firearms.


Reply
 
Thread Tools Display Modes
  #1  
Old 06-03-2020, 06:58 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Hot Bluing at home

Hot Caustic Bluing

As promised, here is a detailed explanation with formula and procedure on how to hot blue at home.

Introduction: I started to search an alternative finish method because I wasn't happy with cold bluing or rust bluing. The results, color and longevity of those finishes wasn't what I was looking for.

I am a hobbyist not a gunsmith or a chemist. I like learning on projects and building things with my kids so they understand the sense of accomplishment when achieving a goal. I don't think this should be intended as a cost saving initiative. In my opinion, if you want to save money perhaps you should cut other expenses in your personal life.

All this info I found online and I cannot take credit for it. I will just try to edit it and add my own learnings.

Disclaimer: HOT CAUSTIC BLUING IS DANGEROUS STUFF. THE BATH BOILS AT 280 TO 295 DEGREES AND THE CAUSTIC SOLUTION CAN BURN YOUR FACE, SKIN, EYES. VAPORS SHOULDN'T BE INHALED.

I CAN NOT STRESS ENOUGH HOW IMPORTANT IS THE PERSONAL PROTECTION EQUIPMENT WHEN DOING THIS: CHEMICAL GLOVES, RESPIRATOR, FACE MASK, LONG SLEVES, CLOSED SHOES, LONG PANTS AND APPRON IS THE MINIMAL PROTECTION GEAR THAT YOU SHOULD WEAR. THIS THREAD IS FOR INFORMATIONAL POURPOSES ONLY. IF YOU DECIDE TO DO THIS, YOU DO IT AT YOUR OWN RISK.

Personal Protection Equipment you should wear


First aid information worth reading just in case: Chemical burns: First aid - Mayo Clinic


Setting your expectations: It is very likely that initial results will not be outstanding. If you are looking for fast and outstanding result, perhaps you should consider sending your slide to a qualified gunsmith.

The good, the bad and the ugly

The good: you might end with a slide like this


The bad: you must deal with this


The ugly: if you are not careful and don't wear personal protection equipment this could happen to you (or worse, you could burn your face, your eyes, etc...)


So, if you are still interested in learning about hot bluing follow this thread...

more to come

Last edited by guzzitaco; 07-02-2020 at 07:32 PM.
Reply With Quote
  #2  
Old 06-03-2020, 08:45 PM
skjos skjos is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: May 2012
Location: South Sound, WA
Posts: 641
Likes: 370
Liked 1,382 Times in 332 Posts
Default

Wow, are those chemical burns or burns related to the temperature of the solution?
Reply With Quote
  #3  
Old 06-03-2020, 08:49 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

Quote:
Originally Posted by skjos View Post
Wow, are those chemical burns or burns related to the temperature of the solution?
that is a sodium hydroxide burn...not mine...related to the temp of the solution and nature of caustic reaction...

"Exposure to sodium hydroxide solid or solution can cause skin and eye irritation. Direct contact with the solid or with concentrated solutions causes thermal and chemical burns leading to deep-tissue injuries. Very strong solutions of sodium hydroxide can hydrolyze proteins in the eyes, leading to severe burns and eye damage or, in extreme cases, blindness."
cdc.gov

The solution generates a reaction that takes it to 240 deg without heat being applied...when heat is applied, it gets to 295 and higher...(if not controlled)

Must wear PPE and be careful...

For more info please read:
Please read: ATSDR - Medical Management Guidelines (MMGs): Sodium Hydroxide

Last edited by guzzitaco; 06-03-2020 at 09:04 PM.
Reply With Quote
The Following User Likes This Post:
  #4  
Old 06-03-2020, 11:52 PM
BC38's Avatar
BC38 BC38 is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Nov 2013
Location: Spokane, WA
Posts: 13,474
Likes: 1,145
Liked 18,397 Times in 7,279 Posts
Default

Yeah, caustics are far more dangerous than acids. The human body is naturally slightly acidic.

Caustics are the opposite end of the PH scale from acids, and acids and caustics create some pretty energetic reactions when mixed. Way more so than mixing two acids together or mixing two caustic compounds together.

A caustic compound on your slightly acidic skin makes for one of those high energy reactions - which means it does MUCH more damage.

For example: battery acid is pretty strong, but a drop on your skin won't even burn you if you rinse it off within a few minutes. But a drop of lye that is the same strength as the battery acid will burn you instantly and eat through your skin within a few minutes.
__________________
Send lawyers, guns & money...

Last edited by BC38; 06-04-2020 at 11:30 AM.
Reply With Quote
The Following 2 Users Like Post:
  #5  
Old 06-04-2020, 07:53 AM
Neversink n Klapperthal's Avatar
Neversink n Klapperthal Neversink n Klapperthal is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2019
Posts: 772
Likes: 1,655
Liked 1,123 Times in 435 Posts
Default

what could go wrong?
Reply With Quote
The Following User Likes This Post:
  #6  
Old 06-04-2020, 08:42 AM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default be prepared

Quote:
Originally Posted by Neversink n Klapperthal View Post
what could go wrong?
Accidents happen...that is why is so important to wear personal protection equipment when working with a caustic reaction...

Also, go through the mental exercise: what would I do if something goes wrong?

I don't like doing any of this alone. I always have a friend or one of my kids to help. Someone that can dial the phone in case of an emergency, or grab a water hose for an emergency wash...
Reply With Quote
The Following 2 Users Like Post:
  #7  
Old 06-04-2020, 08:44 AM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Definitions

Some definitions

Bluing:
Bluing is a method commonly used on gun metal in which various gun parts are submerged in caustic hot salt baths (caustic reaction) for a period in-order to attain the coat. This isn't the only method to obtain the oxide layer, it's but one of many. Some sources have stated that bluing provides rust resistance while others are skeptical since most oxide layers because of the process are merely 2.5 micrometers (0.0001 inches) in thickness.

Caustic reaction:
Caustic corrosion/gouging occurs when alkalinity of boiler water increases. Caustic corrosion is also called caustic attack. Caustic corrosion develops from deposition of feed water corrosion products in which Sodium Hydroxide (NaOH) and other components can concentrate to high PH levels. At high PH level corrosion occurs forming oxide.

Sodium hydroxide
Sodium hydroxide is also known as lye or soda, or caustic soda. At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air. It is a synthetically manufactured substance. When dissolved in water it releases substantial amounts of heat, which may prove sufficient to ignite combustible materials. Sodium hydroxide is highly corrosive. Sodium hydroxide is generally used as a solid or a diluted in a 50% solution. This chemical is used to manufacture soaps, rayon, paper, explosives, dyestuffs, and petroleum products. It is also used in processing cotton fabric, laundering and bleaching, metal cleaning and processing, oxide coating, electroplating, and electrolytic extracting. It is commonly found in commercial drain/ oven cleaners.

Potassium Nitrate
Potassium Nitrate is a crystalline salt, KNO3; a strong oxidizer used especially in making gunpowder, as a fertilizer, and in medicine. Potassium nitrate appears as a white to dirty gray crystalline solid. Water soluble. Noncombustible, but accelerates the burning of combustible materials.

more to come...
Reply With Quote
The Following 3 Users Like Post:
  #8  
Old 06-04-2020, 10:48 AM
PeteC PeteC is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: May 2020
Posts: 1,406
Likes: 2,459
Liked 2,029 Times in 796 Posts
Default

Welll... there should be lots of surplus PPE on the market soon,
Reply With Quote
The Following 3 Users Like Post:
  #9  
Old 06-04-2020, 10:54 AM
stansdds stansdds is online now
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Apr 2007
Location: Virginia
Posts: 8,712
Likes: 19,273
Liked 11,732 Times in 5,350 Posts
Default

Quote:
Originally Posted by guzzitaco View Post
Hot Caustic Bluing



I CAN NOT STRESS ENOUGH HOW IMPORTANT IS THE PERSONAL PROTECTION EQUIPMENT WHEN DOING THIS: CHEMICAL GLOVES, RESPIRATOR, FACE MASK, LONG SLEVES, CLOSED SHOES, LONG PANTS AND APPRON IS THE MINIMAL PROTECTION GEAR THAT YOU SHOULD WEAR. THIS THREAD IS FOR INFORMATIONAL POURPOSES ONLY. IF YOU DECIDE TO DO THIS, YOU DO IT AT YOUR OWN RISK.

Personal Protection Equipment you should wear


First aid information worth reading just in case: Chemical burns: First aid - Mayo Clinic


Setting your expectations: It is very likely that initial results will not be outstanding. If you are looking for fast and outstanding result, perhaps you should consider sending your slide to a qualified gunsmith.

So does you think I be ok usin' mah wife's kitchen gloves, corony-virus mask, mah WalMart sunglasses, mah Bon Jovi T-shirt, mah cut-off jeans, an' mah flip-flops fer mah pee-pee-eeeeee?



Seriously, this is a hazardous process, one mistake is all it takes to ruin your day or ruin your life. Beware and heed the cautions.
__________________
VCDL, GOA, NRA
Reply With Quote
The Following User Likes This Post:
  #10  
Old 06-04-2020, 04:38 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Hardware & equipment

Hardware

Container or tank: you will need a container for the bath. Commercial tanks are a bit expensive but are large enough to fit a rifle/shotgun barrel. Since I only blue slides and small parts and we are discussing a “home” setup, I used a pot.

Pot can made of steel (avoid stainless-steel since it can leave mark on the parts). It must be large enough to fit the part suspended in the solution, without touching the sides of the bottom (if parts sit of the bottom they will develop a reddish spot that will stay and the finish will not be even). The steel pot CAN NOT have aluminum rivets for the handles. The solution WILL MELT the aluminum rivets creating a hazardous situation.

Another alternative is to use a ceramic coated pot, like the ones sold at Walmart. They will run for about $15 to $20.



Please remember, you cannot use an aluminum pot because it will MELT.

If you are going to use an old pot, you MUST wash it very well and remove ALL grease (use a degreaser like TSP). If you cannot remove all the grease, you cannot use it. Once the pot has been used for the caustic solution you can never use it for cooking again. NEVER.

Thermometer:
You will need a stainless-steel thermometer and that reach up to 350 deg. It must be long enough to reach the bottom of the pan. No, you cannot use an aluminum thermometer because it will melt. You can find one for around $15



Stirring rod:
You will need a large spoon or a stirring rod. I use a large stainless-steel spoon that I have (and never used) from an old BBQ set. Some people use a glass rod (large and strong enough). Do not use wood, it could react with the caustic solution.

Heat Source:
You need a stove gas or electric, large enough that your pan can sit on it and powerful enough that can boil water. Your stove must be leveled; sturdy and stable to prevent any kind of accidents and to let you work comfortably. Some people use a camping stove or an outdoor burner.

Place to work:
You cannot do this in your kitchen or inside your home. Fumes are corrosive. It is simply too dangerous. Working area must be ventilated and well illuminated. You need space to move around without stumbling with boxes and you will need a place to sit. You will also need access to running water in case of an accident. A fire extinguisher on hand is also a good idea.

Other things you will need: A table next to the heat source, where you can work (I don't like putting things or working on the floor). And a timer.

What I use:
I have an old stainless-steel pot. It is not too big, but big enough for a slide and some parts. I have a stainless-steel spoon (BBQ) and a stainless-steel kitchen thermometer (the wife had 2 so I stole one). My heat source is a Weber grill that has a side burner. My house has a detached garage, that is where I set the bluing bath. I have enough space to move around comfortably. I have a water hose ready and an extinguisher nearby. I use my phone’s timer and camera.



more to come...

Last edited by guzzitaco; 06-15-2020 at 01:58 PM.
Reply With Quote
The Following 4 Users Like Post:
  #11  
Old 06-04-2020, 11:23 PM
skjos skjos is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: May 2012
Location: South Sound, WA
Posts: 641
Likes: 370
Liked 1,382 Times in 332 Posts
Default

A lot to take in, I have a stainless turkey cooker, but the handles appear to be aluminum and I use it to cook deep fried goodies, so I would need to purchase a dedicated container, thermometer, and stirring rod. I'm looking pretty good on the PPE.
Reply With Quote
The Following User Likes This Post:
  #12  
Old 06-05-2020, 07:37 AM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

Quote:
Originally Posted by skjos View Post
A lot to take in, I have a stainless turkey cooker, but the handles appear to be aluminum and I use it to cook deep fried goodies, so I would need to purchase a dedicated container, thermometer, and stirring rod. I'm looking pretty good on the PPE.
The pot I use is not big, it is only 4 quarts = 128 oz.

Since I wanted to leave 1 1/2 to 2 inches of space from the top because the formula boils...my max working volume of solution is = 114 oz

I avoided a large pot, because I didn't want to mix that more formula. I was concerned enough with the caustic reaction, so didn't wanted to mix a lot of it. Also, it is more expensive to run bigger batches.

Last edited by guzzitaco; 06-05-2020 at 07:38 AM. Reason: spelling and grammar
Reply With Quote
The Following 4 Users Like Post:
  #13  
Old 06-05-2020, 08:37 AM
PeteC PeteC is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: May 2020
Posts: 1,406
Likes: 2,459
Liked 2,029 Times in 796 Posts
Default

Awesome thread and information. Btw, cheap old stainless steel pots can sometimes be found at Goodwill, garage sales,... because most people don't use the 6 -quart size that used to come with sets. I have an extra one came from there, and the old plastic handles are removable with a Phillips screwdriver.

(Now if Goodwill just started selling some cheap old stainless steel firearms.... )
Reply With Quote
The Following 3 Users Like Post:
  #14  
Old 06-05-2020, 04:02 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Commercial products

Commercial Salts
Before attempting to mix salts in a formula, I decided to investigate what was available in the market.

Brownells (not affiliated with them) offers bluing salts that gunsmiths have been using for years. The store is well known for the quality of the products they sell and its customer service. The problem that I had was that the size of the container was huge…40-pound pail !!!…that was enough to do all the slides I wanted to do in three lifetimes!!! I needed a different option.

There is another company called EPI that sells a product called Ultra Blak 400 …the product and the company have an excellent reputation. They even have a variation that is in a liquid form, so you don’t even have to mix it. The problem here is that the shipping cost was skyrocket high because the product is considered hazardous. Unfortunately, this wasn’t an option for me either, since I was learning and wasn’t ready to invest a lot (plus we were in the middle of quarantine and I wasn’t generating any income). The company has great videos of their products on youtube.

There are a couple of other interesting videos in youtube for you to see. Neither videos display good safety protocol (PPE is not being used, one of the guys is wearing flip flops), also there is not clear temp control to time control, so please do not use this as an example of HOW to do this, but they will give you an idea of the process, how the solutions boil and a snapshot of the results…(I suggest you turn the volume OFF in the first one, music isn't great)



Both videos use an electric fryer as a heat source and as a tank...I think is a great idea, unfortunately I don't have one I could use (my wife gave me the look when I suggested it...)


I found some other commercial products, but at this stage I was ready to mix my own salts.

more to come...

Last edited by guzzitaco; 06-05-2020 at 04:08 PM.
Reply With Quote
The Following 6 Users Like Post:
  #15  
Old 06-06-2020, 04:15 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Clarification

Clarification on tanks (Pots) and stirring rods materials

I’ve gotten a couple of questions on this, so I think it would be good to clarify.

The solution tanks must be steel or ceramic coated. Soldered or brazed seams will dissolve, ruining solution, tanks, and whatever gets leaked on. (AVOID STAINLESS-STEEL, IT CAN LEAVE MARKS ON THE PARTS !!!)

The solution slowly attacks glass when very hot but at room temperature it can stirred with a glass rod. So, before applying heat you can use a glass rod to stir the solution but after you apply heat, you shouldn’t use glass.

Last edited by guzzitaco; 06-15-2020 at 02:01 PM.
Reply With Quote
The Following User Likes This Post:
  #16  
Old 06-06-2020, 04:38 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Formula

As with any recipe, there are many of hot bluing formulas. Most gunsmiths have their own touch or twist…like a secret sauce…

However, I think many of them derive from Roy Dunlap gunsmithing book (found on page 399 of NRA published copy).

Dunlap attributes this formula to Don Lowery and says this produces an unbelievably durable finish that can take a wire brush test without damage. I have tested this, it is strong but it is NOT Melonite, it will wear off, but in my opinion it is more durable that other factory bluings I have seen.


The Formula:
5 pounds lye
2 1/2 pounds potassium nitrate
per gallon of DISTILLED water


Calculating formula by weight:
1 gallon of distilled water = 8.3 pounds
5 pounds of lye
2.5 pounds of potassium nitrate
total = 15.8 pounds

By Percentage
distilled water = 52.53%
lye = 31.6%
potassium nitrate = 15.8%

I use a small kitchen scale to measure everything. Keep the proportions and adapt it to the container size you are using.

For example I use a 4Q stainless-steel pot = 128 F Oz. You must leave 1 ½ to 2 inches of space from the top of the pot, so the solution has room to boil without spilling over (causing a safety hazard). I estimated my max working volume at approx. 100 F Oz.

1bl= 16 fl Oz

52.53% of 100 F Oz. = 52.53 = 53 Oz of distilled water = 3.31 pounds of distilled water
31.6% of 100FOz. = 31.6 Oz of lye = 1.97pounds of lye = 2 pounds of lye
15.8% of 100 f Oz. = 15.8 Oz of potassium nitrate = 1 pound of potassium nitrate.
Total solution = 101 Fl oz = 6.31 pounds

I have use rounded figures therefore there is a small rounding error.

Apply the percentages to you max working volume. I calculated my max working volume in a very easy way. I took a 20 Oz container and filled it with water…I used ti to fill my pot until I had 2 inches from the top. 5 containers to fill = 100 Oz.

Note: Please check my calculations, I am human and make mistakes (I make a lot of mistakes, more than most humans )

Materials:

Lye (please read definition in post #7)



I buy the lye at Walmart. Cost is $5 per pound

You may use other brands but make sure that is 100% lye and that is does not contain aluminum shavings in it. Also, you can buy pure lye online (maybe around $2 a pound), but shipping may be expensive.

Potassium Nitrate (please read definition in post #7)



I buy the potassium nitrate at Lowes. Cost is $6 per pound

You may use other brands but make sure that is 100% potassium nitrate.

Distilled Water:



I buy the distilled water at Walmart. Cost is $0.78 per gallon.

Cost to run a batch on bluing solution:
So, using a 4q stainless-steel pot, I need:

2 points of lye = $10
1 pound of potassium nitrate = $6
1 gallon of distilled water = $0.78

Total = $17. Plus the propane you consume on your heat source...

more to come...
Reply With Quote
The Following 5 Users Like Post:
  #17  
Old 06-07-2020, 09:49 AM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Bath operation

How the bath works:

Pour the distilled water into the pot. SLOWLY add the sodium hydroxide (lye) to the distilled water while stirring. The mixing will begin an exothermic reaction that will raise the temperature to around 240 F Deg. Once thoroughly mixed, slowly add the potassium nitrate.
Continue stirring. When everything is mixed, turn on the burner (mid temp to start with) and heat the mix to 285-295 F a that temp you can put the parts inside the bath.

The solution must be kept at a constant boiling between 285-296 deg F. (No boiling, no reaction, no bluing)

The tough part is to keep the temp at 285 -295 F. The solution contains water at around 50%, water boils and evaporates at 212…so, at 295 the solution is evaporating water (consuming water) to keep the reaction going. As water evaporates the temperature starts to increase, but the bath only is “effective” between 285 and 295 deg. So, you must control the temperature and maintain it at the 285-295 rage for the bluing process to be effective.

Larger bath has more water, but same range temperature, so they have more water to “burn” before you need to add more water.

Smaller baths at the same temp, have less water to “burn”, so they will tend to increase temp faster.

The problem is to keep the temp between 285 to 295.

To reduce the temp, after the increase caused by water evaporation, you have 2 options: add more water or reduce the heat.

Once you reduce the heat the boiling stops. When the boing stops, the reaction stops. So, the bluing stops. (I made this mistake the first time I did the process, resulting in a brown part).

Depending on your tank size you may have to add more water. Adding water to a hot caustic solution is VERY DANGEROUS. Water must be added very SLOWLY, VERY SLOWLY.

A large amount of water, violently added to the solution is DANGEROUS it will generate a boil over and can cause a steam eruption that could burn you. Add water slowly very slowly. I start to add water as soon as the temp reaches 290. You will see the level of the bath decrease, then it is time to add water. (Be extra careful in doing this and make sure to wear your PPE)

In the video below you can see how water is added to a Caustic solution (the person doing it should be wearing chemical gloves, but I think it is important to see the water reacting to the solution). Minute 1:02 adding water.


A safer method to add water is to turn off the heat, let the solution cool down and then add water. However, this will make the process longer, much longer.

Another alternative is to mix more bluing solution, before starting, and keep the spare solution handy adding it the main solution as it dries up.

What I do:
I run a small tank (pot), water evaporates every 15 minutes (approx.) and the solution starts to get above 295. I add water slowly. I wear all the PPE and try to keep a distance. I have to add water 3 to 5 times in the 45 to 50 min the process takes.

A good idea is to use a lab safety bottle, so you can keep more distance while adding water.



A bottle like this costs $7 at Grainger. It is a good investment.


more to come...

Last edited by guzzitaco; 06-07-2020 at 10:04 AM.
Reply With Quote
The Following 3 Users Like Post:
  #18  
Old 06-07-2020, 03:30 PM
JohnHL JohnHL is offline
SWCA Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Aug 2013
Location: Foothills of the Ozarks
Posts: 3,582
Likes: 10,598
Liked 5,549 Times in 2,170 Posts
Default

Maybe I'm over complicating this, Guzzi, but would it be safer to add small amounts of boiling water?

John?
Reply With Quote
The Following User Likes This Post:
  #19  
Old 06-07-2020, 06:32 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

Quote:
Originally Posted by JohnHL View Post
Maybe I'm over complicating this, Guzzi, but would it be safer to add small amounts of boiling water?

John?
Hi John,

I honestly don't know, maybe the reaction would be less "violent" if the water is hot but I am not sure.

I think the problem with the water is due to the caustic reaction itself, where the lye (sodium hydroxide) generates a reaction when it interacts with water. Maybe warm or hot water, would make the reactions less violent, but there will be a reaction...

As I read it in another forum: ("Add water . . ." Such a simple statment. Adding water to a working blueing bath is a bit like adding water to the working lead pot. Neither the bath nor the water like it!) (I guess it's like me at my in-laws Xmas dinner )

The only "safer" way to add more "liquid" that I have found (reading) is to add more bluing solution. So, you would have to mix extra bluing solution and use it to re-fill the one that is evaporating...however, my concern would be the higher saturation of salts...

I am sorry I don't have a better answer at this point...

Last edited by guzzitaco; 06-07-2020 at 07:12 PM.
Reply With Quote
The Following User Likes This Post:
  #20  
Old 06-07-2020, 08:17 PM
Dieseltech56's Avatar
Dieseltech56 Dieseltech56 is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Jul 2017
Location: Pittsburgh PA
Posts: 1,764
Likes: 1,648
Liked 3,117 Times in 1,014 Posts
Default

I’ve been wanting to try home bluing for some time now but I was turned off by the cost and volume of the solutions at brownells. This is honestly the info I’ve been looking for
__________________
-Matt
Reply With Quote
The Following 2 Users Like Post:
  #21  
Old 06-08-2020, 06:53 PM
2152hq 2152hq is offline
Member
Hot Bluing at home  
Join Date: Sep 2005
Posts: 7,724
Likes: 1,633
Liked 9,091 Times in 3,362 Posts
Default

I always used a plain steel tank for hot salt bluing,,never stainless.
That was the way to do it.
I think Brownells still advises to use a plain iron tank for Hot Salt Blue.

Stainless steel tank for hot blue would/could cause problems and leave small light colored spots and streaks on the blued pieces.
Something to do with reaction betw the stainless and the hot chemical salts ,, Some sort of electro-reaction thing (?).


Sometimes the stainless tank will work fine and then it won't for certain parts.
I'd guess the steel alloy of the gun parts you are bluing probably has something to do with wether that elec process develops betw the stainless and the parts that leaves the discolorations.
When it does it also ruins the batch of salts in the tank so you loose that also.

I don't do hot salt blue anymore. But still do rust blue.
Stainless Steel tank for that.

Be very careful when hot bluing. Make sure the set-up is Very Sturdy and can't tip over or collapse. That tank full of 300*F salts is very heavy.
If it goes over there is almost no escaping it.

Also, as the tank is boiling and the water is boiling off as steam,,that steam carrys with it the salts that you dissolved into the water to make the bluing concoction.
As the steam condenses in the room it leaves those white salts in a dense fine granular form on every surface in the room.
You can see them in one of the pics beginning to build up on the Thermometer.
They'll be on every shelf, door frame, table,,the floor, everywhere. If you have an exhaust fan,,the fan and it's blades will be covered with the white stuff.
It can be a mess.,,and remember part of that white granular stuff is Lye.

Keep the wife, kids, pets and neighbors out and away from the area you are working in.
It's not a spectator sport. It's dangerous enough for you. No need for others to be in the way.
Reply With Quote
The Following 3 Users Like Post:
  #22  
Old 06-08-2020, 07:30 PM
chief38's Avatar
chief38 chief38 is online now
Member
Hot Bluing at home  
Join Date: Apr 2006
Posts: 17,759
Likes: 7,835
Liked 25,615 Times in 8,661 Posts
Default

gutzitaco:

I give you lots of credit!

Bluing is one aspect of personal gunsmithing I've never attempted - probably never will. As you said, it's toxic, messy and dangerous and unless you do it often and on a regular basis - not really worth it.

I've only had 3 guns in my lifetime ever re-blued and I sent them out to the Pro's. I've attempted cold bluing many many times with marginal results. But like I said - kudos to ya!
Reply With Quote
The Following 2 Users Like Post:
  #23  
Old 06-08-2020, 08:57 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

Quote:
Originally Posted by chief38 View Post
gutzitaco:

I give you lots of credit!

Bluing is one aspect of personal gunsmithing I've never attempted - probably never will. As you said, it's toxic, messy and dangerous and unless you do it often and on a regular basis - not really worth it.

I've only had 3 guns in my lifetime ever re-blued and I sent them out to the Pro's. I've attempted cold bluing many many times with marginal results. But like I said - kudos to ya!

Thanks a lot Chief !!!

I have never blued a revolver, but I have done a couple of slides and I am in the process in doing a third one...

The color is black...a deep, beautiful metallic black...however, it is missing some of that "blue" that I believe comes from manganese ,that is not in the formula...

I will continue the thread soon... !!!
Reply With Quote
The Following User Likes This Post:
  #24  
Old 06-08-2020, 10:00 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

Quote:
Originally Posted by 2152hq View Post
I always used a plain steel tank for hot salt bluing,,never stainless.
That was the way to do it.
I think Brownells still advises to use a plain iron tank for Hot Salt Blue.

Stainless steel tank for hot blue would/could cause problems and leave small light colored spots and streaks on the blued pieces.
Something to do with reaction betw the stainless and the hot chemical salts ,, Some sort of electro-reaction thing (?).


Sometimes the stainless tank will work fine and then it won't for certain parts.
I'd guess the steel alloy of the gun parts you are bluing probably has something to do with wether that elec process develops betw the stainless and the parts that leaves the discolorations.
When it does it also ruins the batch of salts in the tank so you loose that also.

I don't do hot salt blue anymore. But still do rust blue.
Stainless Steel tank for that.

Be very careful when hot bluing. Make sure the set-up is Very Sturdy and can't tip over or collapse. That tank full of 300*F salts is very heavy.
If it goes over there is almost no escaping it.

Also, as the tank is boiling and the water is boiling off as steam,,that steam carrys with it the salts that you dissolved into the water to make the bluing concoction.
As the steam condenses in the room it leaves those white salts in a dense fine granular form on every surface in the room.
You can see them in one of the pics beginning to build up on the Thermometer.
They'll be on every shelf, door frame, table,,the floor, everywhere. If you have an exhaust fan,,the fan and it's blades will be covered with the white stuff.
It can be a mess.,,and remember part of that white granular stuff is Lye.

Keep the wife, kids, pets and neighbors out and away from the area you are working in.
It's not a spectator sport. It's dangerous enough for you. No need for others to be in the way.
You are right...
a normal steel tank can be use and yes Brownells still sells them as an alternative (they even sell black iron tanks). However, they also sell stainless-steel ones for bluing.

From what I have read: "It works okay in an iron tin can but for production work it is best used in stainless steel troughs/tanks, but since iron will not rust in a strongly alkaline environment, then plain bare steel will work great for occasional use if drained and rinsed. "

It all depends on how well you rinse the steel or black iron tank after the process is completed.

Regarding the marks using a stainless-steel tank: I'be never had them. From what I've read the issue only occurs when the part is not suspended in the solution and is touching the bottom or sides of the part.

more to come...
Reply With Quote
The Following User Likes This Post:
  #25  
Old 06-09-2020, 09:15 AM
chief38's Avatar
chief38 chief38 is online now
Member
Hot Bluing at home  
Join Date: Apr 2006
Posts: 17,759
Likes: 7,835
Liked 25,615 Times in 8,661 Posts
Default

Quote:
Originally Posted by guzzitaco View Post
Thanks a lot Chief !!!

I have never blued a revolver, but I have done a couple of slides and I am in the process in doing a third one...

The color is black...a deep, beautiful metallic black...however, it is missing some of that "blue" that I believe comes from manganese ,that is not in the formula...

I will continue the thread soon... !!!
I bet if you did some serious research you could get the formula (or at least really close) for the Royal Bluing Colt use to do. No Factory did routine Bluing like Colt! From everything I read - it's ALL ABOUT the preparation and polishing, but the durability of the old vintage Bluing was terrific!
Reply With Quote
The Following User Likes This Post:
  #26  
Old 06-09-2020, 01:02 PM
2152hq 2152hq is offline
Member
Hot Bluing at home  
Join Date: Sep 2005
Posts: 7,724
Likes: 1,633
Liked 9,091 Times in 3,362 Posts
Default

Quote:
Originally Posted by guzzitaco View Post
You are right...
a normal steel tank can be use and yes Brownells still sells them as an alternative (they even sell black iron tanks). However, they also sell stainless-steel ones for bluing.

...
The Stainless Steel tanks Brownells sells for Bluing are intended for 'other operations' done during the Bluing process.
...Hot Water Cleaning, rinsing, oil soak, ect.
Also fine for Rust bluing.

They still don't recommend Stainless for the Hot Salt Blue tank itself.
Also note the Never Braze the joints of the tank.
Copper can really screw up the bluing salts.

Some bluing operations won't even HotBlue a part if it has been Hard Soldered because of the possibility of even a small amt copper being in the Hard Solder alloy and making the soln flat.
I asked them if gold inlays were OK to Hot Blue and they said sure.
Then I pointed out that if the inlays were less than 24k yellow gold (10k, 14k, ect) that they were an alloyed with copper & zinc.
They had no answer why that alloyed copper didn't mess up the bluing salts but Hard solder and Braze would.
But it was their set up, so their rules.

That was one reason I did my own hot bluing at the time.

 >
>From Brownells:
  Black Iron: Suitable for all solutions used in the bluing operation.
(Note: All seams on the metal tanks must be welded; they must never
be brazed, because it takes less than .001 oz. of free copper per gallon
of Bluing Solution to “kill” a Bluing Solution.)

    Stainless Steel: Suitable for all solutions used in the bluing operation, Except for bluing salts,
Because there is the possibility of electrolytic action between the bluing salts, the stainless steel and the
gun metal...
>
>

When I went from a full tank that was capable of doing rifle and shotgun bbl's down to a smaller set up for pistol frames and small parts,,I used a
US 50cal ammo can as the 'bluing tank',

I bought a nice condition one with a tight fitting lid. Stripped the paint except for the lid.

The ammo can was a perfect size for what I needed then. The bonus was that lid.
Being an air tight fitting lid,,once the blueing salts and tank were cooled off from use, I could simply place the lid on it and snap it shut.
Set the box with the salts in it most anywhere. It won't leak and is safe from kids getting into it if you slip a small lock on it.


The bluing salts are hygroscopic(?),,they absorb water from the air so covering them keeps them from getting a pool of water in there.
The salts will also 'grow' as they absorb moisture from the air and creep up the sides of the tank and around the top. Quite a mess as pieces break off, ect.

It's an easy way to store the mixed salts and keep them ready for re-use.
Break the surface of them upon the next reheating so you don't get a small explosion of crusty salts from the surface caused by melted salts trying to escape from below the surface.
Small volcano activity,,another thing to watch for when Hot Bluing/reheating the old salts.

Hot Salt bluing can be a lot of work. Rebluing/refinishing IS a lot of work when you figure in the polishing and the disassembly/reassembly too.

But there's a lot of satisfaction when a fine job results.
Have fun, be careful. You're one of few that's doing hot salt bluing anymore.
Reply With Quote
The Following User Likes This Post:
  #27  
Old 06-15-2020, 01:55 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default stainless-steel is no bueno

Quote:
Originally Posted by 2152hq View Post
The Stainless Steel tanks Brownells sells for Bluing are intended for 'other operations' done during the Bluing process.
...Hot Water Cleaning, rinsing, oil soak, ect.
Also fine for Rust bluing.

They still don't recommend Stainless for the Hot Salt Blue tank itself.
Also note the Never Braze the joints of the tank.
Copper can really screw up the bluing salts.

Some bluing operations won't even HotBlue a part if it has been Hard Soldered because of the possibility of even a small amt copper being in the Hard Solder alloy and making the soln flat.
I asked them if gold inlays were OK to Hot Blue and they said sure.
Then I pointed out that if the inlays were less than 24k yellow gold (10k, 14k, ect) that they were an alloyed with copper & zinc.
They had no answer why that alloyed copper didn't mess up the bluing salts but Hard solder and Braze would.
But it was their set up, so their rules.

That was one reason I did my own hot bluing at the time.

 >
>From Brownells:
  Black Iron: Suitable for all solutions used in the bluing operation.
(Note: All seams on the metal tanks must be welded; they must never
be brazed, because it takes less than .001 oz. of free copper per gallon
of Bluing Solution to “kill” a Bluing Solution.)

    Stainless Steel: Suitable for all solutions used in the bluing operation, Except for bluing salts,
Because there is the possibility of electrolytic action between the bluing salts, the stainless steel and the
gun metal...
Hi 2152hq,

you are absolutely right...!

It took me a lot of time and research to confirm your points, since there is conflicting info...

but yes, stainless-steel tank could cause and adverse reaction and leave marks on the parts...so, it will be better to use a regular steel tank or a ceramic coated one.

I guess I have been lucky, because I haven't had any issues...

I apologize for the confusion and I will amend the previous posts...

thank you 2152hq

PS: sorry it took me so long to reply. It was a tough week at work and I needed to do some research before answering...

Last edited by guzzitaco; 06-15-2020 at 02:03 PM.
Reply With Quote
The Following 2 Users Like Post:
  #28  
Old 06-17-2020, 07:48 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Preparing parts

Parts preparation:

Make sure the parts are clean. Any oil on the part will ruin the bluing job. I like cleaning parts with Simple Green and/or TSP. If parts are too greasy/oily perhaps boil parts in TSP.

The finish that you use to prepare the part will affect the bluing outcome:

1) Polished parts will have a glossy bluing. Any polish imperfections will show in the bluing. If you are a “rookie, like me; perhaps is best to leave the job up to a mx of 600 grit. Be careful, all the slides I have sanded using a flat granite or marble block are not “flat”, in other words, they are not perfect. This will affect your ability to “sand” and “polish” everything to a square finish. BE CAREFUL NOT TO ERASE ROLL-MARKS BY OVER-SANDING. (don’t ask me how I learned)



2) Blasted parts will have a flat/sating finish. The grittier the blast, the flatter the finish. I use McMaster Econo Blend #4 (same I use for Stainless-Steel to replicate factory finish). For a flatter finish, perhaps it would be a good idea to use a 120-grit aluminum oxide in the blasting job.



Run a wire though the large parts (slide and frames) to suspend them in the solution.

Any water marks will show. To avoid water marks, I suggest you wipe the parts using denaturalized alcohol on a cotton swab or an “ultra clean” cotton rag. (work over an “ultra clean” cotton rag on your bench).


(water mark, had to re-do the bluing job)

DO NOT CLEAN THE PARTS WITH BRAKE CLEANER: IT WILL LEAVE “WATER” MARKS. BRAKE CLEANER REACTS WITH NITRILE AND RUBBER GLOVES, LEAVING ETCHING MARKS ON THE SLIDE. YOU MAY HAVE TO RE-BLAST THE PART (DON’T ASK ME HOW I KNOW).

Suspend the parts in the bath with wire to keep them away from the bottom and sides of the pot. You need to have a boiling solution surrounding the parts on all sides. If they get into a hot spot, you will often see red smut on the parts, or it may impart a plum color to the blue. Small parts can be strung together with iron wire or placed into a steel basket.



Parts should stay inside the bath for 20 to 50 min depending on the steel alloy. The 2 slides I have blued, I have left them for 50 minutes, to make them black. (BATH MUST BE BOILING FOR THE 50 MIN OR IT WON’T WORK AS EXPECTED).

After you take the parts out of the bath, you must rinse them in a bucket of water for 1 to 2 minutes. (water should not be cold, you can use tap water).

Examine the piece after the water rinse. If the color is ok continue. If the color isn’t dark enough: dry the water without leaving any water marks and re-insert it in the bath.

After rinsing the part in water bucket, remove the wire, and wash it in the sink carefully. The part will be “soapy” (remember that lye is used to make soap), so be CAREFUL not to drop it and ruin everything. Once is clean, dry it with paper towels and a hair dryer.

Use wd-40 to coat the part and displace any water remaining.


(soaking in WD-40)

Leave the part for at least 8 hours submerged in Mobil 1 (or other synthetic oil of your choice).

Wipe it clean.

Examine the part carefully for any rust buildup over the next 2-3 days. Why?: There are tiny gaps that can have small (tiny) particles of caustic reaction that are still “working” over the metal. DO NOT PANIC. Clean the rust with a cotton swab and some oil and you will be ok.

Sometimes, the part comes out of the bath with some “marks”. Wipe them out with a paper towel. If they persist, use 0000 steel wool (GENTLY) to remove them. If the persist, you may have a permanent mark.

more to come...

Last edited by guzzitaco; 06-17-2020 at 09:53 PM.
Reply With Quote
The Following 3 Users Like Post:
  #29  
Old 06-18-2020, 12:06 AM
JohnHL JohnHL is offline
SWCA Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Aug 2013
Location: Foothills of the Ozarks
Posts: 3,582
Likes: 10,598
Liked 5,549 Times in 2,170 Posts
Default

Absolutely LOVING this!!!

John
Reply With Quote
The Following User Likes This Post:
  #30  
Old 06-18-2020, 05:02 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Colors

Color variations in hot caustic bluing

When done properly, hot caustic bluing will result in a deep black metallic color. Its is not blue, nor has shades of blue. It is black, deep metallic black (beautiful in my humble opinion). There are some formula variations where some manganese is added to obtain a more "blue" tone, but I haven't experimented with it (yet )

There can be color variations due to many factors. Here some of them:

No color, or red or purple tones can be due to low temperature, copper contamination, low potassium nitrate, high carbon alloys or too little time in the bath.

Brownish or pale black (grey) colors can be caused by low temperature or not enough boiling action in the bath.

Green can be caused by cooper contamination

Splotchy or un-colored spots can be caused by poor cleaning or oil contamination. Sometimes this can be fixed while blueing by scrubbing with degreased “0000" steel wool.

A powdery black that scrubs off is caused by a worn out bath. No color can be caused by a worn-out or overheated bath, wrong amounts of chemicals or (in old baths) by caustic being used up by CO2 in the air. (will explain further in re-using the bath section)

I've had color issues the two times I have done the process:

First time: Had a mistake in the formula, water ratio was too high compared to the salts, so the formula was weak. Additionally, I left the part only 20 min in the bath, because I thought it was the max time. The 20 min time is only for reference, depending of the steel alloy it might take longer. I re-balanced the formula and re-inserted the part into the bath (properly cleaned, no water marks) left if for 50 min. A nice black color was obtained.

Second time: I was re-using the bath, but "someone" in my house had spilled some of the formula on the garage floor. So, I added more water. Same mistake as before. I left it for 50 min and the color was a gunmetal gray, beautiful, but I wasn't looking for gunmetal grey. (I must say that I think a lot of the potassium nitrate was evaporated the first time I used the bath and also, I left the tank "open", so the reaction with the air made the formula weaker)

Stripped the bluing, re-balanced the formula (I over saturated the formula by adding 1/3 of the original mix), and everything work fine.

more to come...

Last edited by guzzitaco; 06-19-2020 at 09:53 AM.
Reply With Quote
The Following 2 Users Like Post:
  #31  
Old 06-22-2020, 03:06 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Barrels and barreled actions

So far, I have never done hot caustic bluing on barrels or barreled actions. However, from what I've read you should blue the barrel as any other part.

Do not plug the barrel when hot blueing/blacking. As the air you've trapped in the barrel heats up the match the 290 degree caustic solution it will expand a lot and it will blow out a plug.

That can make a mess with the caustic solution...

Below a video of a gentleman bluing a barreled action.


Note: the gentleman should be wearing PPE...

more to come...
Reply With Quote
The Following User Likes This Post:
  #32  
Old 06-23-2020, 11:17 AM
2152hq 2152hq is offline
Member
Hot Bluing at home  
Join Date: Sep 2005
Posts: 7,724
Likes: 1,633
Liked 9,091 Times in 3,362 Posts
Default

When hot bluing bbl'd actions or even revolver frames with their bbl attached, there's always the chance that any lube placed on the threads of either part during assembly will liquify and weep out of the joint betw the two.
That'll spoil the bluing right at the joint and if excessive, can run down the parts and cause even further spread of bluing damage.
No bluing at all, streaks, discoloration, ect.
You can have this same problem in Rust Bluing as well.

The other problem with hot salt bluing the bbl'd assemblys as one piece is that they are not a water tight fit in many instances.
During the bluing process, the hot salt soln makes it way into the threaded joint. Most times that salt soln can be washed & rinsed away in the post bluing rinse.
Sometimes not. Sometimes you think you have it all out and there's still some in there. There's no way of seeing it, it looks clear from the outside.

What trips you up is what appears later on. It may be a few days to a few weeks later.
A white bloom growth starts to appear around the joint. That's the dried bluing salts still trapped in the joint (or any parts you have blued).
The bluing salts attract water from the air and start to 'grow'. That's the white growth you see.
It'll keep growing and crawling onto the outside surfaces of the parts. Since it's wet and alkali,,it rusts and pits the steel it's on. The bluing is gone underneath.

If you've been around to shops and gunshows looking at enough reblued guns, especially bolt rifles,,you've probably noticed the problem on more than a few. Usually the white stuff is brushed off and oiled for a better appearance just before sale time. But the spoiled blue and the rust and perhaps pitting around the joint is hard to cover.
M98 Mausers are very prone to it as the shoulder of the bbl does not fit tightly to the front of the action. That allows the soln to get in there very easily. Tough to rinse completely out.

Oiling the stuff won't 'kill' it. It'll just grow back.
Plain boiling water will disolve it and can be rinsed away. That was supposed to happen in the original rinse after bluing, but didn't.

Sometimes a re-rinse can remove it for you, sometimes not.
Usually the finish is damaged and metal pitted already once it's growing on the outside of the parts.
Then it's remove the bbl time. Flush the stuff off.
Repolish and re-blue as separate pieces and reassemble.

The last part is the safest way to avoid the problem in the first place.

>
>added
You're right,,no plugs in the bbl when Hot Salt Bluing.
Totally un-needed and dangerous if done.

Also don't hot salt blue any bbl's or parts with soft soldered (lead) sights, ribs, sling swivel bases, ect attached.
The soln will degrade the lead component of any Lead alloy soft solder. The soldered joint will fail. It may take a few weeks or a few months, but it will break down and fail.
(Ithaca hot-blued the very last run of NID SxS shotgun bbl's in 20 & 16ga's that they made.
Another post war idea of doing things faster.
Then they started to see the soft soldered rib joints fail.
The entire lot of bbl assemblies were scrapped. The guns never re-bbl'd)

Since the soln attacks the lead in soft solders,,the newer (No Lead) Tin/Silver alloy soft solders are supposed to be safe to go through Hot salt Blueing.
I still don't trust them too, but I guess science is not on my side!

Another 'trick' to be able to hot blue soft soldered (lead alloy) joined parts was to add a small amt of potassium cyanide to the bluing soln.
The cyanide salts retards the action of the bluing soln on the lead in the solder.
I've seen that done. I did work for a 'smith that used to do that. He mixed his own salts too. Very proud of himself as a self taught chemist.
I stayed clear of the Bluing Room when picking up and delivering work after that.

I Rust Blue anyway.

Last edited by 2152hq; 06-23-2020 at 11:39 AM.
Reply With Quote
The Following User Likes This Post:
  #33  
Old 06-23-2020, 11:26 AM
SAFireman's Avatar
SAFireman SAFireman is offline
SWCA Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2009
Location: Home of the Alamo
Posts: 5,814
Likes: 16,456
Liked 15,491 Times in 3,085 Posts
Default

Quote:
Originally Posted by 2152hq View Post
When hot bluing bbl'd actions or even revolver frames with their bbl attached, there's always the chance that any lube placed on the threads of either part during assembly will liquify and weep out of the joint betw the two.
That'll spoil the bluing right at the joint and if excessive, can run down the parts and cause even further spread of bluing damage.
No bluing at all, streaks, discoloration, ect.
You can have this same problem in Rust Bluing as well.

The other problem with hot salt bluing the bbl'd assemblys as one piece is that they are not a water tight fit in many instances.
During the bluing process, the hot salt soln makes it way into the threaded joint. Most times that salt soln can be washed & rinsed away in the post bluing rinse.
Sometimes not. Sometimes you think you have it all out and there's still some in there. There's no way of seeing it, it looks clear from the outside.

What trips you up is what appears later on. It may be a few days to a few weeks later.
A white bloom growth starts to appear around the joint. That's the dried bluing salts still trapped in the joint (or any parts you have blued).
The bluing salts attract water from the air and start to 'grow'. That's the white growth you see.
It'll keep growing and crawling onto the outside surfaces of the parts. Since it's wet and alkali,,it rusts and pits the steel it's on. The bluing is gone underneath.

If you've been around to shops and gunshows looking at enough reblued guns, especially bolt rifles,,you've probably noticed the problem on more than a few. Usually the white stuff is brushed off and oiled for a better appearance just before sale time. But the spoiled blue and the rust and perhaps pitting around the joint is hard to cover.
M98 Mausers are very prone to it as the shoulder of the bbl does not fit tightly to the front of the action. That allows the soln to get in there very easily. Tough to rinse completely out.

Oiling the stuff won't 'kill' it. It'll just grow back.
Plain boiling water will disolve it and can be rinsed away. That was supposed to happen in the original rinse after bluing, but didn't.

Sometimes a re-rinse can remove it for you, sometimes not.
Usually the finish is damaged and metal pitted already once it's growing on the outside of the parts.
Then it's remove the bbl time. Flush the stuff off.
Repolish and re-blue as separate pieces and reassemble.

The last part is the safest way to avoid the problem in the first place.
S&W actually had this problem with front sights that we pinned, polished, and blued in place. I have seen it on model 27's.

What would be the benefit of bluing something that had crevices (threads) while assembled vs in pieces?
__________________
On the Oak Savannah
Reply With Quote
  #34  
Old 06-23-2020, 12:49 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

I have had the problem with slides around the barrel bushing area... the barrel bushing can not be removed and re-installed easily, so I have left it in place. If the water rinse isn't done properly, then the salts resurface and it is a bit of a nightmare...that space is tiny, but it happens...

I think the idea of boiling the part in water to get rid of all the salts is great...I will do it the next time to make sure all traces of the caustic solution are "boiled off".

I guess some people avoid disassembling parts to make the job easier...but cutting corners can be worse later...

Last edited by guzzitaco; 06-24-2020 at 09:57 AM.
Reply With Quote
The Following User Likes This Post:
  #35  
Old 06-24-2020, 01:29 PM
2152hq 2152hq is offline
Member
Hot Bluing at home  
Join Date: Sep 2005
Posts: 7,724
Likes: 1,633
Liked 9,091 Times in 3,362 Posts
Default

Bluing the parts as an assembly avoids having to reassemble finished blued parts and risk scratching or marring the new finish doing so.
Also risk damaging a frame or action by bending it in the removal process. Some are a real brute to remove.

...and not everyone that did/or does hot bluing has the bbl vise and all the necessary bbl clamp blocks of different forms and sizes and different frame and action blocks to take apart and reassemble everything that might come at them.

>
>
One of the laziest, incompetent hot blue operations I ever saw was a small shop that I did some out-work for in the 70's and 80's.
They were the repair shop/armorer I'd guess you'd call it for a local small PD. That PD was using Colt OP's and some P/PSpecials.
This shop did repairs when necessary *they did have an original Colt Armorers Chest stocked w/new parts.
What service they also provided was about once every yr or so was to refinish some % of the total # of revolvers.

The refinishing process was to remove the wooden grips,,remove the cylinders.
That was the disassembly process.

Any obvious scars or pitted areas got a quick swipe on a 180grit soft wheel buffer.

Then the frame with all it's parts still in it and the cylinder and crane with all the parts still assembled went into the hot blue cleaner tank, then rinse then right into the hot blue soln.

After being 'blued',, the assemblys were rinsed, oiled and cyl reassembled to frames. Grips reattached.
Here ya go boys..
Reply With Quote
  #36  
Old 06-26-2020, 08:26 AM
stansdds stansdds is online now
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Apr 2007
Location: Virginia
Posts: 8,712
Likes: 19,273
Liked 11,732 Times in 5,350 Posts
Default

Quote:
Originally Posted by 2152hq View Post
>
One of the laziest, incompetent hot blue operations I ever saw was a small shop that I did some out-work for in the 70's and 80's.
They were the repair shop/armorer I'd guess you'd call it for a local small PD. That PD was using Colt OP's and some P/PSpecials.
This shop did repairs when necessary *they did have an original Colt Armorers Chest stocked w/new parts.
What service they also provided was about once every yr or so was to refinish some % of the total # of revolvers.

The refinishing process was to remove the wooden grips,,remove the cylinders.
That was the disassembly process.

Any obvious scars or pitted areas got a quick swipe on a 180grit soft wheel buffer.

Then the frame with all it's parts still in it and the cylinder and crane with all the parts still assembled went into the hot blue cleaner tank, then rinse then right into the hot blue soln.

After being 'blued',, the assemblys were rinsed, oiled and cyl reassembled to frames. Grips reattached.
Here ya go boys..
Wow!!!! How long before the blueing salts retained inside the frame corroded the lock work and turned the revolver into a paperweight?
__________________
VCDL, GOA, NRA
Reply With Quote
  #37  
Old 06-26-2020, 02:09 PM
JohnHL JohnHL is offline
SWCA Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Aug 2013
Location: Foothills of the Ozarks
Posts: 3,582
Likes: 10,598
Liked 5,549 Times in 2,170 Posts
Default

Hey, maybe those guys developed a super secret and effective way of rinsing the salts from the interiors of those revolvers?

Then again, they were probably just gun butchers.

John
Reply With Quote
The Following 2 Users Like Post:
  #38  
Old 07-01-2020, 09:04 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default Sources + final comments

Hi guys...

some things that are still missing from this thread.

Sources:

In case you want to learn more and or double check all the info I condensed.

http://guntechtips.com
(everything started here, fantastic description of the process, and how to)

Royal blue Bluing - Pistolsmith
(interesting discussion about formulas and "tones" of bluing)

https://www.brownells.com/userdocs/l...ng_Booklet.pdf
(good explanation of how to use brownells formula, also serves as a reference of the process)

Hot Caustic Bluing - Show and Tell - Bladesmith's Forum Board
(good explanation of formula and process)

3 Ways to Blue a Gun Barrel - wikiHow
(good explanation of the process, good illustrations)

http://castboolits.gunloads.com/show...-Blueing-Salts

http://castboolits.gunloads.com/show...36054-Hot-Blue


Thanks, and Acknowledgments

Thank you all for all the contributions and the likes.

Thanks to: skjos, BC38, Neversink n Klapperthal, PeteC, stansdds, JohnHL, Dieseltech56, 2152hq, chief38 & SAFireman for all your comments in this thread.

Final thoughts

Forum member skjos gave me the idea of creating this thread. I have to admit I was very hesitant given how dangerous the process is and I almost didn't write it. But then I had a different thought, I am more afraid of becoming someone that does not try anything.

I have been trying to teach my kids the value of learning things. Of being able to repair stuff. Go hunting, fishing, shooting. Use tools, tie knots, use a compass, read a map, ride a motorcycle, shoot a gun. I am terrified of the thought of the next generation becoming people that the only thing they can do is watch TV and play playstation.

I hope that this thread serves as an inspiration to others to start their own projects and teach us what they learn in other new threads.

And, if you decide to do hot caustic bluing at home, please for the love of God wear your PPE.

God Bless

Last edited by guzzitaco; 07-02-2020 at 07:24 AM.
Reply With Quote
The Following 5 Users Like Post:
  #39  
Old 07-01-2020, 11:40 PM
JohnHL JohnHL is offline
SWCA Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Aug 2013
Location: Foothills of the Ozarks
Posts: 3,582
Likes: 10,598
Liked 5,549 Times in 2,170 Posts
Default

Amen.

John
Reply With Quote
The Following User Likes This Post:
  #40  
Old 07-02-2020, 06:58 AM
stansdds stansdds is online now
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Apr 2007
Location: Virginia
Posts: 8,712
Likes: 19,273
Liked 11,732 Times in 5,350 Posts
Default

Excellent tutorial and I think you stressed the safety and precautions aspects quite well.
__________________
VCDL, GOA, NRA
Reply With Quote
The Following User Likes This Post:
  #41  
Old 07-02-2020, 07:25 AM
raljr1 raljr1 is online now
SWCA Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Jun 2011
Location: Northeast FL
Posts: 5,749
Likes: 7,410
Liked 15,075 Times in 3,596 Posts
Default

I would never try to do this, but I enjoyed reading the thread. Thanks to the OP for his time and effort to share this with us.
__________________
Robert
SWCA #2906, SWHF #760
Reply With Quote
The Following User Likes This Post:
  #42  
Old 07-02-2020, 04:25 PM
JohnHL JohnHL is offline
SWCA Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Aug 2013
Location: Foothills of the Ozarks
Posts: 3,582
Likes: 10,598
Liked 5,549 Times in 2,170 Posts
Default

STICKY!

STICKY!

STICKY!

STICKY!

STICKY!

Lets keep chanting this until it happens!!

John
Reply With Quote
The Following 2 Users Like Post:
  #43  
Old 07-03-2020, 07:20 AM
stansdds stansdds is online now
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Apr 2007
Location: Virginia
Posts: 8,712
Likes: 19,273
Liked 11,732 Times in 5,350 Posts
Default

I second John's motion that this post be made a sticky.
__________________
VCDL, GOA, NRA
Reply With Quote
The Following 2 Users Like Post:
  #44  
Old 07-03-2020, 06:38 PM
Troystat Troystat is offline
Member
 
Join Date: Feb 2009
Location: CA
Posts: 1,529
Likes: 790
Liked 678 Times in 436 Posts
Default

Very nice write up thanks for posting it. For all of you do it yourselfers be very careful with all of this stuff, guzzitaco is spot on about the dangers. Also somebody mentioned potassium cyanide, that stuff can be very dangerous I would hate to see somebody poison themselves or a loved one. Look forward to seeing a competed gun from Guzzitaco.
Reply With Quote
  #45  
Old 07-04-2020, 08:38 AM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

Quote:
Originally Posted by Troystat View Post
Very nice write up thanks for posting it. For all of you do it yourselfers be very careful with all of this stuff, guzzitaco is spot on about the dangers. Also somebody mentioned potassium cyanide, that stuff can be very dangerous I would hate to see somebody poison themselves or a loved one. Look forward to seeing a competed gun from Guzzitaco.
Thanks Troystat...

I have done a couple...(posted in the semi-auto forum)

SSV Frankengun Project

M910 Slide learning project

here a couple of pics:



Reply With Quote
The Following 2 Users Like Post:
  #46  
Old 11-07-2020, 08:57 PM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

Found an interesting video on Youtube that describes the whole process...

It is a bit long, but I think is good...


Reply With Quote
  #47  
Old 11-07-2020, 09:33 PM
Warren Sear's Avatar
Warren Sear Warren Sear is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Apr 2011
Location: Twin Cites, Minnesota
Posts: 5,141
Likes: 10,957
Liked 10,857 Times in 3,275 Posts
Default

Quote:
Originally Posted by guzzitaco View Post
..."Exposure to sodium hydroxide solid or solution can cause skin and eye irritation."...
That is an example of what could be accurately termed an understatement.
Reply With Quote
The Following User Likes This Post:
  #48  
Old 11-07-2020, 10:48 PM
BC38's Avatar
BC38 BC38 is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Nov 2013
Location: Spokane, WA
Posts: 13,474
Likes: 1,145
Liked 18,397 Times in 7,279 Posts
Default

Quote:
Originally Posted by Warren Sear View Post
That is an example of what could be accurately termed an understatement.
Got that right.
The PH of human tissue is slightly acid.
Sodium hydroxide is a caustic - at the opposite side of the PH scale.
Acids react very strongly with caustics, so caustics do WAY more tissue damage than acids.
__________________
Send lawyers, guns & money...
Reply With Quote
  #49  
Old 11-09-2020, 01:31 PM
cherrypointmarine's Avatar
cherrypointmarine cherrypointmarine is offline
SWCA Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Jul 2013
Location: Oviedo,Fl
Posts: 2,309
Likes: 627
Liked 4,883 Times in 1,574 Posts
Default

I can see your wife letting you do the metal work , but how did you talk her in to letting you do this ? Seriously though , looks like the parts are coming out nicely , keep up the good work !
Reply With Quote
The Following User Likes This Post:
  #50  
Old 11-10-2020, 10:31 AM
guzzitaco's Avatar
guzzitaco guzzitaco is offline
Member
Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home Hot Bluing at home  
Join Date: Sep 2018
Location: Pompano Beach, FL
Posts: 574
Likes: 1,126
Liked 2,134 Times in 378 Posts
Default

Quote:
Originally Posted by cherrypointmarine View Post
I can see your wife letting you do the metal work , but how did you talk her in to letting you do this ? Seriously though , looks like the parts are coming out nicely , keep up the good work !
We have a detached garage...I sneak out without asking for permission...
Reply With Quote
The Following User Likes This Post:
Reply

Thread Tools
Display Modes

Posting Rules
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
New Guy Intro. littlesonny New Members Introduction 22 10-02-2017 08:52 PM
New Guy Intro Web Design Guy New Members Introduction 9 03-29-2012 04:46 PM
intro shooterdown New Members Introduction 7 04-21-2010 08:58 AM
New Guy Intro 88usnret New Members Introduction 7 02-01-2010 12:25 PM
Intro Larry Ternes New Members Introduction 10 10-30-2009 01:30 PM

Powered by vBadvanced CMPS v3.2.3
smith-wessonforum.com tested by Norton Internet Security smith-wessonforum.com tested by McAfee Internet Security

All times are GMT -4. The time now is 09:15 AM.


Smith-WessonForum.com is not affiliated with Smith & Wesson Holding Corporation (NASDAQ Global Select: SWHC)