Red tinge on brass means zinc leached?

[Tex1001]

Rather than hijack another thread, I started a new one to address a point made on that thread. Here is the poster's statement
>Scooter123:
I've used the white vinegar solutions suggested in various places on the net and after observing a "red dusting" in the cleaned brass I stopped using these solutions. Because that reddish tinge is a clear indication that zinc is being leached out of the brass.<

Here is my problem. I tumble cases with walnut and auto compound and I get a beautiful shine on almost all of my cases. I had several hundred cases that weren't corroded but they were almost black (This seems to be a real problem with NORMA cases). When I tumble these, they come out smooth and shiny, but still black.
I read on this forum about Barkeeper's Friend and tried it on these nasty cases with results that could only be described as fantastic. I soak cases, dry them, and walnut tumble and they look like the rest of the cases (New).
Here's what bothers me about scooter's post:
After drying, these formerly nasty cases have what I would describe as a "Red dust". The dust is removed when tumbled. Does my "Red dust" mean zinc is leaching? No failures so far, but now I'm gettin' skittish.
Scooter, are you there?
_______________________
I don't have Alzheimer's- My wife had me tested.

[rsrocket1]

Brass with the zinc leached out typically as a pink tint to it on the surface of the brass, not red dust. Its a surface action. So long as you don't do this regularly, you probably haven't weakened the brass by very much.

Did you try a Scotchbrite pad?

[sbrmike]

I would look real hard at the auto compound and insure there is no hint of ammonia in it. Even the fumes from ammonia will weaken brass!

[Tex1001]

Originally Posted by rsrocket1

Did you try a Scotchbrite pad?

No, too much brass & I'm too lazy.
_______________________
I don't have Alzheimer's- My wife had me tested.

[Tex1001]

Originally Posted by sbrmike

I would look real hard at the auto compound and insure there is no hint of ammonia in it.

No ammonia anywhere, thanks.

_______________________
I don't have Alzheimer's- My wife had me tested.

[Rule3]

Barkeepers Friend has Oxalic acid.

Once again, there is no problem using these mild acid solutions. The problem comes about if you mix them to strong, leave the brass soak to long or do not rinse the brass at least 3 times.

As mentioned if left to long the brass turns a dark color. Never seen the Mars Dust.

I would not worry about, But then I do not know the above questions.

If you look at the commercial cleaners sold for ultra sonic and wet tumbling they are acid based.(usually citric acid around 15%)

[scooter123]

IIRC Barkeepers friend is based on acetic acid, otherwise know as Vinegar. So it can leach the zinc out of brass. Unfortunately my Chemistry classes date back to college in the mid 70's so I'm working with memories that are a bit sketchy. However, as I recall it the process of zinc being leached out of brass is Galvanic Corrosion, an electrochemical reaction that takes place when dissimilar metals are exposed to a wet bath containing certain salts and acids. If you are using a stainless steel bowl in your cleaning the presence of that stainless steel will enhance the galvanic process taking place. BTW, every ultrasonic cleaner made features a stainless steel bowl for the bath.

Now, here is where things are a bit sketchy for me and my memory of the exact process may be a bit flawed. However, here is what I think is going on. That is that the Zinc and Copper in the brass are functioning as an Anode and the stainless steel bowl is the cathode. What is happening is that both metals are being dissolved into the solution but because zinc is far more reactive than copper the copper that is dissolved in the solution precipitates out, thus forming that pink or red dusting on the brass.

The good news here is that it takes a lot of time before there is a real loss in strength in the brass. So, a single 10 or 20 minute bath wont have much effect. However don't make it a habit.

[Tex1001]

Originally Posted by scooter123

The good news here is that it takes a lot of time before there is a real loss in strength in the brass. So, a single 10 or 20 minute bath wont have much effect. However don't make it a habit.

I soak 'em for a max of 5 minutes and they come ready to tumble.
I got the original idea from this forum. A lot of guys here swear by Barkeeper's Friend.
Thanks for the chemical expertise. My specialty is electronics.

_______________________
I don't have Alzheimer's- My wife had me tested.

[Doubless]

Acetic acid is a covalent acid. That means it does not ionize all that well in solution. The idea that a weak acid is able to work its way inside a solid metal item that is amalgamated on a molecular level and pull a specific element out of it is preposterous.

Period.

It just doesn't happen...

If you want to prove this one way or the other, take some brass cases, put them into a bowl of vinegar/water solution and leave them for a week. If there is any zinc leaching there will be holes in the brass where the atoms of zinc have been removed and in effect turned into a liquid, leaving holes where the zinc atoms were.

But I will save you the time: it ain't gonna happen...

[Maximumbob54]

Been using Barkeeper's Friend for several years now. Fill a big glass bowl with warm water, sprinkle some over the top, pour in brass, and set an hour. Come back, stir, pour off water into big plastic jug, rinse off brass, air dry, into the tumbler with a mix of walnut media premixed with NuFinish, let tumble an hour or two, and badda-bing it all looks like gold again. When I pour off the water from the bowl I use a funnel to catch it in the plastic jug. I just use my fingers to hold the brass from pouring. I find it lasts several uses and it's easy to tell when it's done because it stops cleaning. If you really want to get into the science then read up on brass passivation.

[Tex1001]

Okay, now my head hurts.
_______________________
I don't have Alzheimer's- My wife had me tested.

[Rule3]

Originally Posted by scooter123

IIRC Barkeepers friend is based on acetic acid, otherwise know as Vinegar. So it can leach the zinc out of brass. Unfortunately my Chemistry classes date back to college in the mid 70's so I'm working with memories that are a bit sketchy. However, as I recall it the process of zinc being leached out of brass is Galvanic Corrosion, an electrochemical reaction that takes place when dissimilar metals are exposed to a wet bath containing certain salts and acids. If you are using a stainless steel bowl in your cleaning the presence of that stainless steel will enhance the galvanic process taking place. BTW, every ultrasonic cleaner made features a stainless steel bowl for the bath.

Now, here is where things are a bit sketchy for me and my memory of the exact process may be a bit flawed. However, here is what I think is going on. That is that the Zinc and Copper in the brass are functioning as an Anode and the stainless steel bowl is the cathode. What is happening is that both metals are being dissolved into the solution but because zinc is far more reactive than copper the copper that is dissolved in the solution precipitates out, thus forming that pink or red dusting on the brass.

The good news here is that it takes a lot of time before there is a real loss in strength in the brass. So, a single 10 or 20 minute bath wont have much effect. However don't make it a habit.

No it is not. I already posted it is Oxalic acid. Look up the MSDS

Soft cleaner has Oxalic and Citric.

Tex 1001, you did not mention what solution you made but here is the correct one.

Add 1 tp 2 cups of white vinegar and 1 tablespoon of salt, a few drops of dish soap to enough water to make 1 gallon. Mix it up.

Soak your brass for 10 minutes or so. Drain it through a colander or strainer so you save your solution (you can use it many times). Then rinse your brass 3 times in another bucket.

Leave it out in the Sun to dry.

I had this set up when I was picking up a lot of really dirty sandy range brass. I use a dry tumbler with corn/walnut and Nu Finish.

You will see Lemi Shine and Barkeeper in the picture. Vinegar is much cheaper and works as well or better.

[Tex1001]

Rule-
My solution is 1-2 tsp. of BF in 2 qt. of water at 200degF. I soak for 15min and drain. Rinse, dry, and tumble to remove the residue.
_______________________
I don't have Alzheimer's- My wife had me tested.

[Rule3]

Originally Posted by Tex1001

Rule-
My solution is 1-2 tsp. of BF in 2 qt. of water at 200degF. I soak for 15min and drain. Rinse, dry, and tumble to remove the residue.
_______________________
I don't have Alzheimer's- My wife had me tested.

I have used BKF also. We use it a lot all around the house and on the boat. Amazing stuff. I love it! Shake it around or stir it around it will help it work,

Just be sure to triple rinse (I used to work with very toxic solvents and chemicals) or it will leave a white powdery residue on the brass (it is the BKF inert ingredients)) not a chemical reaction

[SMSgt]

My solution is to stop worrying about shiny brass, "clean" it with anything and load it.

[johngalt]

I've seen the term 'red rot' used with musical instruments. If it is just surface corrosion, then the cases may be ok. If it goes all the way through, the metal has failed and it is done.

[Rule3]

Originally Posted by Tex1001

Rule-
My solution is 1-2 tsp. of BF in 2 qt. of water at 200degF. I soak for 15min and drain. Rinse, dry, and tumble to remove the residue.
_______________________
I don't have Alzheimer's- My wife had me tested.

I duplicated you "recipe" let some 9mm soak for 10 minutes, Shake and stir. Rinsed 3 times.

No "Mars "dust or and discoloration of the brass

They shine but still have my Sharpie mark on the bottom and some carbon on them. Perfectly fine to reload though.

My tumbler with corn , walnut Nu Finish still cleans them better,

[venomballistics]

in the way back days when I first learned to pull the handle on an O frame, I played with a few cleaning solutions.
after seeing "dalmatian" brass, and the subsequent case cracking, I abandoned it.

Today, I just let the tumbler do its job, however long that may take.
If it takes too long, get another tumbler and solve the problem through volume.
If its still too long .. its still a volume problem. get a cement mixer, spray the inside with truck bed liner and let her eat.
If that still isn't enough, I envy you for your horde of loading minions and the ability to shoot in your sleep.

[Rule3]

I posted this on the other thread that morphed into cleaning. I shall repost for those who don't care

Have you guys that use Ultrasonic and Wet tumblers ever read the ingredients or MSDS for the solutions sold by say Hornady?

It is Citric acid!

So all this hoopla about acid is nonsense.

Sure if you use a strong concentrate and leave it in there to long then you will have problems.

About 100 years ago my Mother and Her Mother used lemon juice (or vinegar) and salt (straigh up!) to clean the copper kettles and pans, Did not see to many of those get dissolved!

We cleaned pennies with it when they were real copper.

I keep saltwater (marine) fish corals and clams. The pumps get serious calcium build up. Vinegar is to slow and weak to clean them. I use a 10 parts water to 1 part muriatic (HCL) to clean them.. Also pour it the pool to lower pH and OMG we swim in it! So if you follow the directions and mix it correctly there is no problem.

Always add acid to water not the other way around. Wear safety glasses.

[Maximumbob54]

I'm finally out of my 40# sack of media from DrillSpot.

They no longer do free drop shipment!!!

[Rule3]

Originally Posted by Maximumbob54

I'm finally out of my 40# sack of media from DrillSpot.

They no longer do free drop shipment!!!

Sent you a PM. Order from Zoro.

[Tex1001]

Originally Posted by Rule3

No "Mars "dust or and discoloration of the brass

I only use BKF on cases that are severely discolored. That discoloration becomes the red stuff. If brass is not discolored I simply tumble with walnut.
_______________________
I don't have Alzheimer's- My wife had me tested.

[Jaymo]

I picked up some .223, .38, 9mm, .45 ACP, .308, and .30-30 brass from the shooting range portion of my hunting lease yesterday.
I'm the only member who reloads or casts/swages boolits.
It was all dark gray to black.
I washed the dirt from it and cleaned it with vinegar/salt/water solution.
It all looks good so far.
I triple rinsed it, hand tumbled it in a plastic coffee container and.put it (spread out in a box with brown packing paper) on the hood of my truck.
It should dry quickly enough.
I'll inspect it, tumble polish it, inspect it again, and load the good ones.
I think I should get my loading buddy to bring.his metal detector next time.