Stainless Steel help - Ruger Security Six

[weimerheimer]

I came across a Ruger Security Six in stainless steel. It's had many years of neglect. There are small spots of pitting on the frame. Is there any thing that I can do to smooth out the pitting marks? The gun does not have shiny chrome-like finish, it has the standard S.S. finish.

 

[Dixie Gunsmithing]

It shouldn't have pitting from corrosion. It may be from the gun laying in a vehicle, etc., and on a hard surface, where the places were actually gouged into it, thus, dings. It would take some strong chemicals to corrode stainless.

Anyhow, the places can be polished out. A good polisher should be able to bring it back to as new condition. The whole gun needs to be repolished, to blend everything, and have it all match.

 

[45_auto]

Typical gun stainless steels are actually very susceptible to pitting. Any damage to the passivation layer can later form pits. I find it very common to find pitting under the grips of stainless guns.

Pitting Corrosion
Pitting occurs when corrosion eats small holes or cavities in the metal. Alloys like stainless steel that are resistant to corrosion due to a passivation layer are actually the most susceptible to pitting. If the passivation film is compromised and then attacked by corrosion, the corrosion will not spread on the metal’s surface but will instead penetrate inward. Pitting may cause stress cracking, and – if a pit occurs as a critical point – it can cause immense damage.

Nothing you can do to smooth out the pitting unless you remove the surface to the depth of the pits. Grit blasting or bead blasting may possibly help hide them if they aren't too bad.

Worst pitted stainless gun I ever saw was a Ruger Old Army fired with black powder. The owner didn't think it was necessary to thoroughly clean it right after shooting like his blued guns. After wiping it down and putting it in the safe for a week, it looked like it had come off the Titanic when he pulled it back out.

Pitted Colt:

Pitted S&W crane:

Pitted Ruger:

Old paper on basic stainless corrosion here:

http://www.parrinst.com/wp-content/...1/07/Parr_Stainless-Steels-Corrosion-Info.pdf

When passive metals such as the stainless steels corrode, the corrosion develops where passivity has been destroyed. This may occur at very small areas and result in a pitted surface. Once the passivity has been lost at a local spot, this area will be anodic to the remaining passive surface. The subsequent development of these active anodic areas into pits will depend upon electrolytic current flowing between the small anodic area and the large unattacked cathodic area outside of the pits.

An article on the stainless alloys Ruger uses is here:

http://www.modernapplicationsnews.com/articles/m0401stainless.htm

One of the claims of the stronger alloys is that they are "almost" as corrosion resistance as 304.

Custom 465®stainless is a premium, double vacuum-melted, martensitic age-hardenable alloy ..... and corrosion resistance approaching that of Type 304 stainless.