How the heck does stainless steel get pitted?

[DepOne]

Years ago I was in my garage cleaning a Model 60 when a neighbor who was a chemical engineer dropped in. I picked up an aerosol can of something and he asked if I was going to spray it on the gun. He recommended only using pump type sprays on anything made of steel as many of the gasses used in aerosol propellants are corrosive, even on stainless. Maybe that has changed by now, but I never again used aerosols on guns and never had a rusting or pitting problem.

 

[Gunsnwater]

Easy way to tell if your stainless gun is apt to rust is test it with a magnet. 300 series like 304 (general purpose) and 316 (marine use) are non magnetic and will not rust because of the high nickle content. Acids and salt water pitting are the biggest problem. 400 series has a high iron content that makes them apt to rust but also makes for a stronger metal. I tested my 686 Pro, it's magnetic.

I know of no stainless used in guns to be non magnetic.

 

[POLSEGR38]

After Googling for best SS gun protectant, this seems to be some pretty great stuff: http://www.steelshieldtech.com/prodsheetpdf/pdfcombined/WeaponShield.pdf

I'm going to order some and spray completely my 2 new SS Rugers in it and let dry or per instructions. It is designed for use on SS guns.

 

[jaymoore]

Here's some of the typical conditions in which the 940 has survived so long with no appreciable pitting. ( There's a little something under the left grip on the all-weather well used, 617.)

The 940 in my pocket was probably soggy as well as the 617 after fording the creek late last winter. :




Attached photos from yesterday's range trip, BTW, including the mud!:

 

[DonD]

Here's some of the typical conditions in which the 940 has survived so long with no appreciable pitting. ( There's a little something under the left grip on the all-weather well used, 617.)

The 940 in my pocket was probably soggy as well as the 617 after fording the creek late last winter. :


Attached photos from yesterday's range trip, BTW, including the mud!:

That looks like a messy trip. On the other hand, firing something powerful into the sloppy mud would amuse me. Don

 

[O2628]

Our service pistols are all stainless Smiths as well and although they are tough as nails they do tend to pit a bit for our guys in the coastal posts. Salt water I suspect is the culprit along with high humidity and sitting in a holster for hours. It just reinforces the need to have a good maintenance regiment and armourer program (for law enforcement agencies in particular).

 

[jaymoore]

That looks like a messy trip. On the other hand, firing something powerful into the sloppy mud would amuse me. Don

That was the concrete sidewalk at the 50 yd line!

 

[DonD]

That was the concrete sidewalk at the 50 yd line!

Funny. When I was young and got my first big bore revolver, a .44 Mag, I had a place that had a stream with steep and deep walls. Was fun to shoot down into it and see the geysers and mud fly w/o any risk at all of a slug going where it shouldn't. Don

 

[Nemo288]

http://www.steelshieldtech.com/prodsheetpdf/pdfcombined/WeaponShield.pdf
I'm going to order some and spray completely my 2 new SS Rugers in it and let dry or per instructions. It is designed for use on SS guns.

That product looks very similar to Eezox and BreakFree CLP
both of which I use. If it smells like Eezox you will be able to tell
where your weapons are a half mile away

My main oil rag is a piece of t-shirt I have had for years that is
lightly infused with a combination of RIG grease and Hoppes oil.
I use this rag to wipe up oil after lubing the press and other items.
It then gets used to wipe off the exterior of weapons after cleaning
and handling. I have had some rifles in the cabinet for decades
without the slightest rusting. It doesn't take much. This rag is
not even that greasy feeling to pick up but you can tell the nice
shine it leaves after a rub down.

---
Nemo

 

[POLSEGR38]

I checked their site and chose this link. The best deal $ around.
Weapon Shield Combo Special! [ws-combo] - $15.50 : WMSI, Online Shopping
From all my research, it's the best product available for gun cleaning and protection.

 

[dbcopeland]

I'm not an expert, but when I worked at GM, we used several grades of stainless to machine fuel injector parts. We mostly used 400 series stainless steel that, like many posted above stated, is rust resistant. That's not to say that 400 is "cheap stainless steel", it's better in some cases just not as rust resistant. The upside is that 400 wears less and last longer in mechanical devices that are prone to wear. 300 is very hard to rust but is very soft and prone to wear more in parts that move against each other because of the increased amount of nickel in it.