Can stainless steel pit or rust???

Claims Rep. · November 24, 2008, 11:39 PM

A friend says he has a GP100 stainless that appears to have some sort of pitting/rust spots. Is this possible? I haven't seen this gun, so I can't attest to the accuracy of what's going on with it. Has anyone seen anything like this, and if it's correct what can be done to get rid of it (acid bath, etc.)

Thanks in advance for the help.

CR

ogree · November 24, 2008, 11:42 PM

Yes.

hoghunting · November 25, 2008, 12:13 AM

Stainless steel can rust. If the rust is on the outside of the gun - not in the barrel - he can buff it out with ScotchBrite. If it's in the barrel, a good cleaning will probably get rid of it unless it is pitted.

James K · November 25, 2008, 12:17 AM

The better term would be "rust resistant", but the term "stainless" is so ingrained that it will never be changed. And for most purposes, it really is stainless or rust proof. Having just completed the "honeydew" job of polishing the "good" silverware for Turkey day dinner, I can darn well tell you that stainless steel is a LOT better. But the silver sure looks great, if I do say so myself.

Jim

brickeyee · November 25, 2008, 01:14 PM

Stainless is less, not none.

There is still iron in the alloy.

Stainless steels are also prone to corrosion from chlorine (chloride).

Stainless is often 'passivated' after machining.
By dunking the stainless in acid any exposed iron is removed leaving a surface that is less prone to rust formation.
The process also removes any smears of tool steel left behind by cutters used.

eth77 · November 25, 2008, 02:18 PM

If you believe SS is really stainless and rust free, look at SS BBQ grills after a couple of seasons. Beneath all the glop, you'll find rusted metal. the chrome, nickle and other alloys gradually vaporize and you're left with iron which rusts.

Sigh, there's not much in this world which wouldn't suffer in that application. Pt maybe, but I don't want to have to store my grill in the bank vault.

drail · November 27, 2008, 11:35 AM

If it is exposed to the proper corrosive, absolutely.

**Unclenick** · November 27, 2008, 12:30 PM

There are what my old company's tool maker used to call "true stainless steels". They are used in surgical instruments and in stainless implants. Can't be having rust going on in your artificial knee. The problem is these alloys are either too soft or too expensive for guns and knives.

dieselone · November 28, 2008, 08:48 AM

Per above, there are many different grades of SS. IIRC, 300 series is more rust resistant than 400 series but not as strong. Differences in the carbon and nickel content. As to your original question: SS can be buffed, polished, ect.. I've even used fine emery paper to put a shine on matte SS. The problem with Rugers is that they do a bead blast type finish on most. If you polish one area, you're going to have to do the whole gun. Ruger might re-do the gun if sent to their service dept.. They recommend a paste wax coating to protect the gun. A friend used to spray his guns with Pledge furniture polish to keep the dust off when displayed. I thought he was nuts at the time but turned out he was actually on to something by accident.

HisSoldier · November 28, 2008, 10:33 PM

I read on one thread some while ago that one of our poor friends who have acidic sweat picked his SS auto up after leaving it for a few days and saw his rusty fingerprints looking back at him. I feel sorry for gun nuts with such sweat!

**Unclenick** · November 29, 2008, 10:13 AM

Rusters is what another tool maker I knew used to call them. He said you go into their shops and every tool they own is rust brown. Keeps the bacteria count on their hands down, though.

Stainless resists rust in part due to a chromium oxide layer that forms on its surface during passivation. If you bead blast it or corrupt that surface in any way, you have to passivate it over again because free iron has been exposed. In addition to nitric acid passivation, I understand citric acid will passivate, albeit very slowly. Just something to consider trying, since that could be done safely at home. I have no idea what the concentrations of duration of exposure would have to be? You would need to get up to some experimenting with stainless drill rod or other samples to find out.

Bill DeShivs · November 29, 2008, 02:09 PM

Stainless steel is self-passivating to a large degree. I don't think the gun makers use chemical passivation.

**4V50 Gary** · November 29, 2008, 05:59 PM

While the advantage of stainless over blued steel is that it is somewhat more rust resistent, its greater advantage is that you don't have to send it out to refinish it. If it's a dull finish, a bit of steel wool will blend in any scratches. You can't do that with a blued gun. If it's a bright stainless, then simichrome will restore it.

November 24, 2008, 11:39 PM	#1
Claims Rep. Member Join Date: January 3, 2008 Posts: 74	Can stainless steel pit or rust??? A friend says he has a GP100 stainless that appears to have some sort of pitting/rust spots. Is this possible? I haven't seen this gun, so I can't attest to the accuracy of what's going on with it. Has anyone seen anything like this, and if it's correct what can be done to get rid of it (acid bath, etc.) Thanks in advance for the help. CR __________________ Blessed beyond measure thanks to Jesus!

November 27, 2008, 12:30 PM	#8
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	There are what my old company's tool maker used to call "true stainless steels". They are used in surgical instruments and in stainless implants. Can't be having rust going on in your artificial knee. The problem is these alloys are either too soft or too expensive for guns and knives. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

November 28, 2008, 08:48 AM	#9
dieselone Member Join Date: November 15, 2008 Posts: 40	Polish and wax Per above, there are many different grades of SS. IIRC, 300 series is more rust resistant than 400 series but not as strong. Differences in the carbon and nickel content. As to your original question: SS can be buffed, polished, ect.. I've even used fine emery paper to put a shine on matte SS. The problem with Rugers is that they do a bead blast type finish on most. If you polish one area, you're going to have to do the whole gun. Ruger might re-do the gun if sent to their service dept.. They recommend a paste wax coating to protect the gun. A friend used to spray his guns with Pledge furniture polish to keep the dust off when displayed. I thought he was nuts at the time but turned out he was actually on to something by accident.

November 28, 2008, 10:33 PM	#10
HisSoldier Senior Member Join Date: August 9, 2007 Location: Oregoncoast Posts: 1,793	I read on one thread some while ago that one of our poor friends who have acidic sweat picked his SS auto up after leaving it for a few days and saw his rusty fingerprints looking back at him. I feel sorry for gun nuts with such sweat! __________________ CNC produced 416 stainless triggers to replace the plastic triggers on Colt Mustangs, Mustang Plus II's, MK IV Government .380's and Sig P238's and P938's. Plus Colt Mustang hardened 416 guide rods, and Llama .32 and .380 recoil spring buttons, checkered nicely and blued.

November 29, 2008, 10:13 AM	#11
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Rusters is what another tool maker I knew used to call them. He said you go into their shops and every tool they own is rust brown. Keeps the bacteria count on their hands down, though. Stainless resists rust in part due to a chromium oxide layer that forms on its surface during passivation. If you bead blast it or corrupt that surface in any way, you have to passivate it over again because free iron has been exposed. In addition to nitric acid passivation, I understand citric acid will passivate, albeit very slowly. Just something to consider trying, since that could be done safely at home. I have no idea what the concentrations of duration of exposure would have to be? You would need to get up to some experimenting with stainless drill rod or other samples to find out. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

November 24, 2008, 11:42 PM	#2
ogree Senior Member Join Date: January 18, 2005 Location: Idaho Posts: 151	Yes.

November 25, 2008, 12:13 AM	#3
hoghunting Senior Member Join Date: March 27, 2006 Posts: 1,559	Stainless steel can rust. If the rust is on the outside of the gun - not in the barrel - he can buff it out with ScotchBrite. If it's in the barrel, a good cleaning will probably get rid of it unless it is pitted.

November 25, 2008, 12:17 AM	#4
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	The better term would be "rust resistant", but the term "stainless" is so ingrained that it will never be changed. And for most purposes, it really is stainless or rust proof. Having just completed the "honeydew" job of polishing the "good" silverware for Turkey day dinner, I can darn well tell you that stainless steel is a LOT better. But the silver sure looks great, if I do say so myself. Jim

November 25, 2008, 01:14 PM	#5
brickeyee Senior Member Join Date: December 29, 2004 Posts: 3,351	Stainless is less, not none. There is still iron in the alloy. Stainless steels are also prone to corrosion from chlorine (chloride). Stainless is often 'passivated' after machining. By dunking the stainless in acid any exposed iron is removed leaving a surface that is less prone to rust formation. The process also removes any smears of tool steel left behind by cutters used.

November 25, 2008, 02:18 PM	#6
eth77 Junior Member Join Date: November 24, 2008 Location: Houston Posts: 6	If you believe SS is really stainless and rust free, look at SS BBQ grills after a couple of seasons. Beneath all the glop, you'll find rusted metal. the chrome, nickle and other alloys gradually vaporize and you're left with iron which rusts. Sigh, there's not much in this world which wouldn't suffer in that application. Pt maybe, but I don't want to have to store my grill in the bank vault.

November 27, 2008, 11:35 AM	#7
drail Junior member Join Date: February 2, 2008 Posts: 3,150	If it is exposed to the proper corrosive, absolutely.

November 29, 2008, 02:09 PM	#12
Bill DeShivs Senior Member Join Date: April 7, 2006 Posts: 10,985	Stainless steel is self-passivating to a large degree. I don't think the gun makers use chemical passivation. __________________ Bill DeShivs, Master Cutler www.billdeshivs.com

November 29, 2008, 05:59 PM	#13
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,841	While the advantage of stainless over blued steel is that it is somewhat more rust resistent, its greater advantage is that you don't have to send it out to refinish it. If it's a dull finish, a bit of steel wool will blend in any scratches. You can't do that with a blued gun. If it's a bright stainless, then simichrome will restore it. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*