Sandblasting media for 6906 (?soft alloy frame?)

[Erniekim]

This is the sandblasted surface. It's kind of light colored but if I leave it alone (no coloring) scratches won't show. Im planning to do a baked on clear coat. Do I need to buy from Brownell or might there be something at a auto store that is as good.?
Thanks

 

[Erniekim]

here is the slightly "brushed" surface. Done with 400 grit sandpaper. I like it a bit better than the sandblasted finish. Old fashioned I guess.

 

[BMCM]

Unfortunately, you're not likely to find any cheap options to make that frame useful again.

You see, raw bare aluminum is pretty soft and in any application where there is steel bearing against aluminum, the aluminum will quickly wear out.

Anodizing is an electrochemical process that essentially grows a very precise layer of interlocking aluminum oxide crystals on the surface of the part from the base aluminum. This layer is covered in micro-pores to permit coloring which are later sealed in another chemical bath such as nickel acetate.

Here's a couple graphics I purloined from the internet showing the tightly packed hexagon crystal structure:

And hard coat anodizing:

Aluminum oxide is otherwise known as carborundum is a very common industrial abrasive. Aluminum oxide is also known as rubies, second in hardness only to diamonds. So you can see when these crystals are grown in a uniform thin precise layer on a surface they impart a great deal of wear resistance to the part.

As an aside, I come across this stuff all the time..... Folks sending sparkling new type III hard anodized gun parts off for some kind of applied finish. If the preparation is done correctly per the coating manufacturers instructions, that layer of anodizing, second in hardness to diamond, is stripped off and replaced with spray paint.

Now, since you've already stripped off much of your anodizing you'll need to have something done to restore it's wear resistance before placing that frame in service, else I'd not expect it to last very long.

I strongly suggest either one of these. Industrial hard chrome or Type III hard coat anodize. I'd lean towards the type III hardcoat anodizing. Back in post #10 I linked an outfit that can do industrial hard chrome.

With the popularity of the modern AR platform there's a huge number of companies anodizing weapon components. Google is your friend in finding them.

Best of luck restoring that frame to useful running condition.

Cheers
Bill

 

[Erniekim]

I found no evidence of anodizing, the frame conducts electricity everywhere.

When I got the gun, there was no paint where the slide and frame contact. So I didn't sandblast there. I assume that this means the previous owner had the anodizing removed before he/she painted it.

The gun functioned well before I tore it down. I guess if it would have been used like this (with no anodizing or protective paint like ceracote to protect the slide-to-frame contact area) it would have been worn down below specs and ruined.

So should I just proceed to hard anodizing at this point? I don't want to remove any material going through the etching process to remove old anodizing before re-anodizing. Does checking for electrical conductivity and seeing that it does indeed conduct electricity guarantee that there is no anodizing remaining?

If I understand correctly, if I go straight to anodizing at this point, it will only accept anodizing if there is no anodizing present. Also the anodizing process will build up any material lost when the previous owner had the anodizing removed.

Or, should I play it safe and ceracote it?

I hate the idea of painting it.

 

[Erniekim]

Another area

 

[Erniekim]

Did the method I used seem correct? Could someone check their anodized frame to see if it does NOT conduct electricity when metered this way? Mine conducted everywhere.

 

[Hill_Country]

Ya'll might be over thinking this just a bit. Based on the 40 years I've been involved in aircraft maintenance - nearly all the aluminum parts on an aircraft are anodized - it really isn't a big deal.

Anodizing – there are several types – is a very thin coating. Thinner even than the Parkerizing type of coating found on black 3d gens. (Which is a layer of phosphate crystals designed to retain oil for lubrication and prevention of oxidation.)

Bare, pure aluminum slowly builds a coating of oxidation. It is kind of like rust on steel except that aluminum oxidation is self limiting unless in the presence of certain chemicals or conditions (like electrosis). Anodizing simply interrupts the oxidation, which on 3d gen frames isn't going to amount to much more than slight discoloration after many years.

Anodizing is not a very thick or hard coating. It is much thinner than Parkerizing and we've all seen how that quickly wears off the rails with no apparent ill effects. If you're really worried about it, go down to the local paint store that sells coatings used on aircraft and pick up a gallon jug of the dilute acid used to anodize aircraft skin before painting. It comes in several different colors or clear. The colors are just so one can tell that the area has been treated. You won't see much difference in the surface until the treated surface wears off and it will probably have a polished appearance when that happens. If you want to strip off all the oils and put the gun away for several years, you find that the base metal is dull colored where the anodizing has worn off, but you'll have to look closely. The dimensional changes will be less than anything you can measure with any tool in your toolbox.

If you're really, really worried about it, get a bottle of the Birchwood Casey aluminum black touch-up and you can reproduce the same finish S&W puts on their aluminum frames.

BTW, you'll not measure any change in the surface conductivity using a multimeter.

 

[NordicG3K]

A little off topic, but if you were going to Cerakote the frame would you media blast the frame or just spray right over the anodizing?

 

[Erniekim]

They sandblast first to give the ceracote something to grip onto. The anodizing is removed if an aggressive blasting media is used.

I've learned a lot since I started this project. It's very apparent that there's a lot of bad information floating around. I did find a forum specifically for people who do plating and anodizing, so I've got good procedures now.

I'm still wavering about the Ceracote though since a lot of coating experts and gunsmiths seem to really like it. I'm just old-fashioned I guess and I like what I like but I don't want to turn into one of those stubborn old guys who won't accept anything new.

Does anyone here think Ceracote is as good as hard anodizing.

 

[MWater]

A little off topic, but if you were going to Cerakote the frame would you media blast the frame or just spray right over the anodizing?

They publish the Cerakote Training Manual online. It's a pretty interesting read.

Begin by plugging the bore at both the chamber and the muzzle end of the barrel prior to blasting. Grit blast the parts with #100 to #120 grit aluminum oxide or garnet sand at 80 to 100 psi. Strive for an even blast pattern over the surfaces of the parts. Lightly blast (30-40 psi) non-metal parts such as: wood, plastic or polymer.

TIP:

• If the part's surface is still shiny after blasting, you haven't blasted enough.
• If you use too coarse of grit, the microscopic valleys on the part's surface will be too deep for the 1.0 mil (.001") coating to completely fill while covering the corresponding "peaks" sufficiently to assure a satisfactory coating.
• Don't use sand that has been previously used to clean dirty, greasy or oily parts. Doing so will contaminate your parts.

 

[Erniekim]

They publish the Cerakote Training Manual online. It's a pretty interesting read.

Do this and your hard anodizing is as good as gone. The paint manufacturer makes sure that you will have to use Cerakote forever on this gun or spend 350 dollars to get it hard anodized again; by someone good with a guarantee.

I've only found one trustworthy vendor that will guarantee they won't melt your gun away (reduce dimensions too much) but they're expensive.

Forget about the DIY anodizing you see online, it's not for guns, only pretty bright colors on paintball guns, bikes and flashlights, and it's not that great for those.

I was told early in this thread that it would be costly to re-do the anodizing. After a lot of research, I totally agree with that position. Now, I'm trying to convince myself that Cerakote is good enough until I find a new frame for the 6096.

 

[Erniekim]

Ya'll might be over thinking this just a bit. Based on the 40 years I've been involved in aircraft maintenance - nearly all the aluminum parts on an aircraft are anodized - it really isn't a big deal.

Anodizing – there are several types – is a very thin coating. Thinner even than the Parkerizing type of coating found on black 3d gens. (Which is a layer of phosphate crystals designed to retain oil for lubrication and prevention of oxidation.)

Bare, pure aluminum slowly builds a coating of oxidation. It is kind of like rust on steel except that aluminum oxidation is self limiting unless in the presence of certain chemicals or conditions (like electrosis). Anodizing simply interrupts the oxidation, which on 3d gen frames isn't going to amount to much more than slight discoloration after many years.

Anodizing is not a very thick or hard coating. It is much thinner than Parkerizing and we've all seen how that quickly wears off the rails with no apparent ill effects. If you're really worried about it, go down to the local paint store that sells coatings used on aircraft and pick up a gallon jug of the dilute acid used to anodize aircraft skin before painting. It comes in several different colors or clear. The colors are just so one can tell that the area has been treated. You won't see much difference in the surface until the treated surface wears off and it will probably have a polished appearance when that happens. If you want to strip off all the oils and put the gun away for several years, you find that the base metal is dull colored where the anodizing has worn off, but you'll have to look closely. The dimensional changes will be less than anything you can measure with any tool in your toolbox.

If you're really, really worried about it, get a bottle of the Birchwood Casey aluminum black touch-up and you can reproduce the same finish S&W puts on their aluminum frames.

BTW, you'll not measure any change in the surface conductivity using a multimeter.

Sorry but you must be thinking of something else, you are not referring to hard anodizing here Hillcountry.

 

[Hill_Country]

Sorry but you must be thinking of something else, you are not referring to hard anodizing here Hillcountry.

I know exactly what I'm referring to and so do the many, many other people on this forum who have successfully refinished their 3d gens either by beadblasting or chemical finishes.

Feel free to add all the drama you want, but don't say you weren't warned. Make it as difficult as you please. You're looking for a problem where there is none.

 

[Erniekim]

There is SO much misinformation on the Internet. Sifting through comments from self-proclaimed experts can be amusing but can also get annoying when they get belligerent.
In spite of this, I'm ready to go and might go ahead and post the process as I go. I was able to get through to the right folks at Smith and Wesson. I even managed to meet the past CEO of Wesson up at Fusion Firearms in Venice Florida. Google their 1911's, Wow, they are nice.
I now have the actual procedures performed by S&W. The frame is 7076 material and they only did type 2 anodizing originally. I found a calculator on a material finishing forum so with the exact material, I can determine the exact voltage, duration and cathode material.

I'll post pictures of the process as I go through it. Thanks to those who were genuinely helpful.

 

[grcoffman104]

here is my friend. He helps me travel the internet.

 

[85V65Sabre]

I was able to get through to the right folks at Smith and Wesson.

Did you by chance ask if S&W offers frame refinishing as mentioned earlier in the thread?

 

[ladder13]

As mentioned, I'd go with a hard chrome by Bob Cogan, he does great work.

 

[Erniekim]

Did you by chance ask if S&W offers frame refinishing as mentioned earlier in the thread?

Sabre,
Yes they do offer refinishing and it's not a bad price. The regular customer service department will tell you that they don't offer it anymore. I didn't give up so easily, asked to speak to the persons manager and he said "sure, no problem". i was told that they would do the following:
1) set up shipping so that you don't have to go through a FFL entity to ship.
2) tear it down and check dimensions to see if it's in tolerance.
3) sandblast
4) do type 2 anodizing
5) reassemble and polishing

I was told that all of this would be done for 150 dollars. Sounds good to me, what do y'all think?

Kim

 

[Erniekim]

As mentioned, I'd go with a hard chrome by Bob Cogan, he does great work.

I'll definitely check it out. Thanks

 

[Big Shrek]

I'm actually starting to wonder if that Gold Paint wasn't actually paint,
but gold anodizing, or plating...
especially since you said it was so hard to remove...

Of course, if it looked good, I'd have kept it gold
Sometimes it is helpful to look like the craziest *** in a room...