I have a stainless K40 that I love.The gun is accurate for what it is and has a great feel.The only thing that bothers me about the gun is a rusting problem.The gun is 2 years old and was just put into service 6 months ago.Ever since then it has been rusting no matter how well I take care of it.Customer service told me to send it back.They said it may need refinished because bad media may have been used the first time.They could not tell me why it took a year and a half to rust.Can anyone tell me if they had this problem with a Kahr pistol or any other stainless pistol.
Rusty stainless K40
- Thread starter goat
- Start date
VictorLouis
New member
Stainless steel isn't. It is rust resistant. The tumbling media used may have left a more "porous" surface than normal. This would allow more bodily acids or oxygen to contact the carbon in the alloy, exacerbating the problem.
Have you had problems w/other stainless guns?
Have you had problems w/other stainless guns?
What Victor Louis says is true. I've got a ATS 34 knife blade that's bead blasted and another of the same stainless steel that's highly polished. The blasted one developes surface rust very quickly if I don't keep it dry or don't coat it w/a light film of oil and it stays wet for a small amount of time. The polished one has stood up to more water expossure, yet has never had any rust whatsoever.
What you describe concurs with what others have said about their Kahrs. People have complained about the finish on Sigs too. I guess it goes to show that you can have a pistol of excellent quality, with a poor finish. Allthesame, its a pain in the butt, (the side that holds the wallet), to have to shell out $100 or more to have an expensive gun refinished. If I were you, I'd ask Kahr if there is a finish that they can apply that would prevent rust formation. If they don't and you want to save money, the supply company Brownells sells do-it-yourself spray on/bake on finishes that supposed to work well when applied properly....at a fraction of the cost of sending it out. That's IF you want to paint your car black.....I mean Kahr.
Best wishes with your machine, goat.
robert
Best
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"But now, he that hath a purse, let him take it, and likewise his scrip; and he that hath no sword, let him sell his garment, and buy one." -Jesus Christ (Luke 22:36, see John 3:15-18)
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"Reasonable gun law?............There's No such critter!" --EQ
What you describe concurs with what others have said about their Kahrs. People have complained about the finish on Sigs too. I guess it goes to show that you can have a pistol of excellent quality, with a poor finish. Allthesame, its a pain in the butt, (the side that holds the wallet), to have to shell out $100 or more to have an expensive gun refinished. If I were you, I'd ask Kahr if there is a finish that they can apply that would prevent rust formation. If they don't and you want to save money, the supply company Brownells sells do-it-yourself spray on/bake on finishes that supposed to work well when applied properly....at a fraction of the cost of sending it out. That's IF you want to paint your car black.....I mean Kahr.
Best wishes with your machine, goat.
robert
Best
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"But now, he that hath a purse, let him take it, and likewise his scrip; and he that hath no sword, let him sell his garment, and buy one." -Jesus Christ (Luke 22:36, see John 3:15-18)
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"Reasonable gun law?............There's No such critter!" --EQ
riddleofsteel
New member
the nice thing about "stainless" steel is that it only takes a few minutes in a glass bead machine to make it look new. i have had several firearms in stainless glass beaded by my gunsmith. it leaves a nice matte finish and does not obsure printing or logos on the gun, it removes any stain or rust discoloration as well as most small scratches and holster burnishing that stainless steel is famous for. i have a stainless K40 i bought used. it had some discoloration already on it, i plan to evaluate it at the end of the summer as to if i will refinish it then. also something to consider is one of the coatings like WW Birdsong teflon, NP3, hard chrome, or something like that. Khars of all metal types are famous for showing rust and stains. like knives you can have harder steel or rust resistance, it's hard to have both.
p.s. i have not noticed bead blasted guns rusting faster than smooth finish stainless. as long as you you use pure glass media to blast. never rub stainless with steel wool or any thing like it to remove rust. it just scratches it and embeds carbon steel in the surface. it will rust then. plus i treat my stainless guns like they were blued. when i remove them from the holster each day i wipe down any exposed surfaces with a silicone cloth. once a week i take down the gun i am carrying and clean it throughly including removing the grips.
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Democracy is two wolves and a lamb voting on what is for lunch.
Liberty is a well armed lamb contesting the outcome of the vote.
Let he that hath no sword sell his garment and buy one. Luke 22-36
They all hold swords, being expert in war: every man hath his sword upon his thigh because of fear in the night. Song of Solomon 3-8
The man that can keep his head and aims carefully when the situation has gone bad and lead is flying usually wins the fight.
[This message has been edited by riddleofsteel (edited April 12, 2000).]
p.s. i have not noticed bead blasted guns rusting faster than smooth finish stainless. as long as you you use pure glass media to blast. never rub stainless with steel wool or any thing like it to remove rust. it just scratches it and embeds carbon steel in the surface. it will rust then. plus i treat my stainless guns like they were blued. when i remove them from the holster each day i wipe down any exposed surfaces with a silicone cloth. once a week i take down the gun i am carrying and clean it throughly including removing the grips.
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Democracy is two wolves and a lamb voting on what is for lunch.
Liberty is a well armed lamb contesting the outcome of the vote.
Let he that hath no sword sell his garment and buy one. Luke 22-36
They all hold swords, being expert in war: every man hath his sword upon his thigh because of fear in the night. Song of Solomon 3-8
The man that can keep his head and aims carefully when the situation has gone bad and lead is flying usually wins the fight.
[This message has been edited by riddleofsteel (edited April 12, 2000).]
Kahrs seem to have rusting problems for some reason.
My Kahr is a K9 parkerized.
No matter what I do to it, it rusts. I oil it, and it rusts. I wax it, and it rusts, I leave it alone, and it REALLY rusts.
I've not contacted Kahr about it, which I need to do. If they don't give me much resolution (I've had it for going on 3 years now and absolutly LOVE it), I'm probably going to send it to Mac Scott for his Gnomekote finish.
My Kahr is a K9 parkerized.
No matter what I do to it, it rusts. I oil it, and it rusts. I wax it, and it rusts, I leave it alone, and it REALLY rusts.
I've not contacted Kahr about it, which I need to do. If they don't give me much resolution (I've had it for going on 3 years now and absolutly LOVE it), I'm probably going to send it to Mac Scott for his Gnomekote finish.
Thats why I sold my K9 awhile back, I couldn't stand the damn rusting inside the magwell-drove me crazy. I really liked the gun though. My buddy just picked up a P9 (going to shoot it this weekend), I'm considering getting one too (its real nice for those that haven't seen one yet).
Well, at least the frame won't have a problem with rust
[This message has been edited by JG (edited April 13, 2000).]
Well, at least the frame won't have a problem with rust
[This message has been edited by JG (edited April 13, 2000).]
Will Beararms
New member
I must beg to differ and I think our new member who is a metallurgist will back me up. SS will rust and it is usually a function of a heat lot of SS that either has two much of a certain alloy or not enough of it. Ruger never ceases to amuse me. They have their "Terrhune Anti-Corro" cast SS slides. I had a P 90 that was rusting in the box when I took it home. At the gun store, I thought it was some dried lubricant. I cleaned it with #9 and a copper brush but it would always come back and guess what? I no longer own that P90. Monday,I went to the gun store to look at the new Ruger P 97. I was about to lay down some coin for one when I saw some more of that dark,dark red, fine grain corrosion forming. That did it for me------no more investment-cast Ruger slides.
Sorry for the soap box post but SS will rust if it is not oiled or if the SS Alloy does not have the right ingredients. I don't know what the warranty is for a Kahr but I can tell you that I would be tempted to tell them to send me a Black T coated carbon steel model and skip the SS altogether. They will have to do some serious grinding to get that much rust off and I can guarantee you that unless you keep the pistol dipped in CLP, it will start again. I am lead to believe that your problem with this Pistol is inherent in the chemical composition of the metal. Good SS alloys will rust but usually only if they have been severely neglected.I have worked in Machine Shop and after that I sold SS Steel, Aluminum and Carbon Steel metal goods for seven years. I have seen and sold large quantities of SS.
I have just about come to the point where I will only utilize a cheap Makarov or Taurus revolver for CCW in environments where there is humidity high heat or constant exposure to moisture. If those rust, what the heck. Then of course, there always the now high-dollar Glock sub-compact line.
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"When guns are outlawed;I will be an outlaw."
Sorry for the soap box post but SS will rust if it is not oiled or if the SS Alloy does not have the right ingredients. I don't know what the warranty is for a Kahr but I can tell you that I would be tempted to tell them to send me a Black T coated carbon steel model and skip the SS altogether. They will have to do some serious grinding to get that much rust off and I can guarantee you that unless you keep the pistol dipped in CLP, it will start again. I am lead to believe that your problem with this Pistol is inherent in the chemical composition of the metal. Good SS alloys will rust but usually only if they have been severely neglected.I have worked in Machine Shop and after that I sold SS Steel, Aluminum and Carbon Steel metal goods for seven years. I have seen and sold large quantities of SS.
I have just about come to the point where I will only utilize a cheap Makarov or Taurus revolver for CCW in environments where there is humidity high heat or constant exposure to moisture. If those rust, what the heck. Then of course, there always the now high-dollar Glock sub-compact line.
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"When guns are outlawed;I will be an outlaw."
I've been carrying mine for only about half a year and I've already starting to see signs of rust. Of course, living in the hot & humid southern Florida swamps where it doesn't make it out of the 80's even in the winter and the fact that I carry it in an inside the waist belly band 16-18 hours a day, 7 days a week might have something to do with it.
In any event, I'm going to have Scott, McDougall & Associates apply their special clear GnomeKote matte finish to the gun which is suppose to exceed the ATSM [American Standard Materials] 177 specifications for salt water corrosion resistance by more than 4000% (or something along those lines) but not chance the appears of the gun as it will still look like the original stainless steel.
Share what you know, learn what you don't -- FUD
In any event, I'm going to have Scott, McDougall & Associates apply their special clear GnomeKote matte finish to the gun which is suppose to exceed the ATSM [American Standard Materials] 177 specifications for salt water corrosion resistance by more than 4000% (or something along those lines) but not chance the appears of the gun as it will still look like the original stainless steel.
Share what you know, learn what you don't -- FUD
Good posts on this topic; rust resistance for stainless is determined by both alloy content and surface finish, but alloy content (primarily chromium content, but nickel and other elements can also affect rust resistance) is more important. The greater surface area of a rough finish will be somewhat more likely to show rust. Harder stainless steels for knives and guns and other high strength applications typically have lower chromium contents than the soft austenitic stainless steels (most inexpensive silverware is 18-8 stainless steel, which means 18%Cr, 8%Ni, and it's quite soft). High chromium content prevents the steel from being quenched to high hardness, so a tradeoff is made between high Cr (rust resistance) and hardenability. Cost is also a factor, with iron being the cheapest ingredient, so the lower the alloy content, the cheaper the steel. Most harder stainless steels are in the 12% Cr range, which is enough to be called stainless, but a lot more prone to rust than the 18-8 stainless steels. Also, any of these steels can corrode in a sufficiently aggressive environment. Cast vs. milled or forged doesn't make a difference unless the casting isn't done well.
[This message has been edited by Nick19 (edited April 14, 2000).]
[This message has been edited by Nick19 (edited April 14, 2000).]
I have a MK40 that I wear here in GA, with the combo of GA heat and humidity, along with me profusely sweating on the gun; the kahr definetely rusts. Until I can part with the gun long enough to have a different finish applied, I have found one thing that helps.
Once a week I clean the gun and then apply chrome polish to the outside of the gun. The chrome polish really slows down the rusting. I am also going to go with a Blade-tech holster eventually to help keep prespiration off of the gun. Other than the rust I really really love my Kahr.
DaHaMac
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Know Yourself, Know Your Weapon, Know Your Enemy; then Know Victory!
Once a week I clean the gun and then apply chrome polish to the outside of the gun. The chrome polish really slows down the rusting. I am also going to go with a Blade-tech holster eventually to help keep prespiration off of the gun. Other than the rust I really really love my Kahr.
DaHaMac
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Know Yourself, Know Your Weapon, Know Your Enemy; then Know Victory!
Master Blaster
New member
Try Flitz metal polish to inhibit corrosion
wipe it off well.
You might also try a good automotive paste wax to seal out the moisture.
Another good sealant is dry teflon spray I use remminton's dry lube.
wipe it off well.
You might also try a good automotive paste wax to seal out the moisture.
Another good sealant is dry teflon spray I use remminton's dry lube.
riddleofsteel
New member
i would rather have a K40 with a few traces of rust on it than most other guns clean as a whistle. honestly i treat the pistol like i would a blued gun and i have not noticed any futher discoloration than what it had when i bought it used. i carry it EVERY day and that is in N.C. HOT and HUMID. but then i take extra good care of it. after all i want it to take care of me.
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Democracy is two wolves and a lamb voting on what is for lunch.
Liberty is a well armed lamb contesting the outcome of the vote.
Let he that hath no sword sell his garment and buy one. Luke 22-36
They all hold swords, being expert in war: every man hath his sword upon his thigh because of fear in the night. Song of Solomon 3-8
The man that can keep his head and aims carefully when the situation has gone bad and lead is flying usually wins the fight.
------------------
Democracy is two wolves and a lamb voting on what is for lunch.
Liberty is a well armed lamb contesting the outcome of the vote.
Let he that hath no sword sell his garment and buy one. Luke 22-36
They all hold swords, being expert in war: every man hath his sword upon his thigh because of fear in the night. Song of Solomon 3-8
The man that can keep his head and aims carefully when the situation has gone bad and lead is flying usually wins the fight.
Sometimes rust resistance can be improved by a "passivated finish," which is a surface treatment for stainless. It consists of dipping the part in an acid solution followed by washing with deionized water. This removes embedded tool steel particles, heat treat scale, etc. and leaves the surface with a rust resisting "film." If you could disassemble the gun (to eliminate trapped fluid) there are jobbers who could do it. There are no dimensional changes from passivation. The 300 series (also 18-8) stainless steels such as 301, 303, 302, 304, 316, 321, etc. are good in corrosion resistance but can be subject to attack by crevice corrosion. They CANNOT be heat treated but can be work hardened, and can be bought in quarter hard, half hard, and full hard condition. 304L and 316L steels have the "L" added for "Low Carbon," and they are much more resistant to attack (316L is superior for marine applications). Examples of heat treatable stainless steels are 17-4PH, 15-5PH, and PH13-8Mo. The "PH" stands for "Precipitation Hardening" which is how these steels are heat treated, an elevated temperature soak followed by air cooling. PH13-8Mo is about the highest strength SS, it can be treated to H900 temper but is notch sensitive and the higher strengths are more susceptible to stress corrosion cracking. They WILL rust, especially from environmental conditions if left outdoors. They are best machined in the finally desired heat treated condition, then passivated and placed in service. 400 series are extremely hard but brittle and find use as ball bearings (440) and some knife blades. 400 series is also very magnetic, the PH series less so. Treatments to harden the surface of stainless steels are limited (can't carburize, for example) but you can use TiN (Titanium Nitride) for high wear applications. The only truly corrosion resistant, heat treatable material is a titanium alloy, such as 6Al-4V (6% Aluminum, 4% Vanadium). If you have cast stainless steel expect a witches' brew of inclusions and flow additives, the inclusions might rust and cause pitting. You might try a hard chrome finish or one of the proprietary coatings, be advised there will be some slight dimensional (additive) changes.
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"Our most pressing problems...are at their core moral, not material, problems." Richard Nixon
"We should not substitute the state for the parents or the family." Lee Kwan Yew
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"Our most pressing problems...are at their core moral, not material, problems." Richard Nixon
"We should not substitute the state for the parents or the family." Lee Kwan Yew
JG said: "but I should add that it was bought blue, then Hard Chromed by Accurate Plating (reputable company)- they did a "very" nice job. But eventually, the inside of the mag well started to rust." Chrome is not stainless. If your gun was initially blue, then it wasn't stainless steel. Stainless steel is not a surface coating, like chrome. Your beef is with the company that did the chrome plating, not with Kahr. Jared
bad_dad_brad
New member
Well, I have a SS MK9. Pocket it in a Uncle Mike's holster every day for 2 years and have not seen a hint of corrosion. I live in a very humid climate.
I do, on a monthly basis, coat the entire pistol in Breakfree CLP. Perhaps this makes the difference.
I do, on a monthly basis, coat the entire pistol in Breakfree CLP. Perhaps this makes the difference.
Nick has a very good point on the surface treatment. How the rust is removed can cause stainless to act just like carbon steel due to what is used to remove it. Stainless can really get ugly due to electrolysis or something. It can really pit up when it does rust and come out worse than carbon steel in the same situation. I think some of the old high nickel steels that were used many years ago may be more rust resistant than much of the SS that is used in guns today. A stainless that is more rust resistant is a real killer on machine tools so most guns are made at the bottom of the spectrum of SS. Buff with SS wool to remove rust and using chrome polish may not be a bad idea.
Food for thought.........I have always been turned off by stainless in firearms. Both by the colour and the tendency for stainless to stainless moving parts to gall, even with the presence of some lubes. Before you jump on me, my carry piece is a 686 2.5".
I do have some experience with both high strength and high hardness stainless as used in wire wheel spokes and knife blades. The stainless used in both applications is prone to corrosion. I have had thousands of pieces electro-polished. The electro-polish is much like reverse electro-plating. The piece is suspended in the proper electrolytic solution and currant passed through. The ferrous ( rustable ) portions are removed, molecule at a time, from the surface and from just below the surface; rendering the piece extremely corrosion resistant. If a high lustre is desired, a light buffing after electro-polishing will render a surface that is very chrome like but far more lasting than chrome.
I do not know what effect, if any, this has on the ductility and tensile strength of the material. I do know that the effect is not enough to be noticed in wire wheel spoke applications.
Worth looking into ???
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Sam I am, grn egs n packin
Nikita Khrushchev!." We cannot expect the Americans to jump from capitalism to communism, but we can assist their elected leaders in giving Americans small doses of socialism, until they suddenly awake to find they have communism."
I do have some experience with both high strength and high hardness stainless as used in wire wheel spokes and knife blades. The stainless used in both applications is prone to corrosion. I have had thousands of pieces electro-polished. The electro-polish is much like reverse electro-plating. The piece is suspended in the proper electrolytic solution and currant passed through. The ferrous ( rustable ) portions are removed, molecule at a time, from the surface and from just below the surface; rendering the piece extremely corrosion resistant. If a high lustre is desired, a light buffing after electro-polishing will render a surface that is very chrome like but far more lasting than chrome.
I do not know what effect, if any, this has on the ductility and tensile strength of the material. I do know that the effect is not enough to be noticed in wire wheel spoke applications.
Worth looking into ???
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Sam I am, grn egs n packin
Nikita Khrushchev!." We cannot expect the Americans to jump from capitalism to communism, but we can assist their elected leaders in giving Americans small doses of socialism, until they suddenly awake to find they have communism."
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by C.R.Sam:
Food for thought.........I have always been turned off by stainless in firearms. Both by the colour and the tendency for stainless to stainless moving parts to gall, even with the presence of some lubes. Before you jump on me, my carry piece is a 686 2.5".
I do have some experience with both high strength and high hardness stainless as used in wire wheel spokes and knife blades. The stainless used in both applications is prone to corrosion. I have had thousands of pieces electro-polished. The electro-polish is much like reverse electro-plating. The piece is suspended in the proper electrolytic solution and currant passed through. The ferrous ( rustable ) portions are removed, molecule at a time, from the surface and from just below the surface; rendering the piece extremely corrosion resistant. If a high lustre is desired, a light buffing after electro-polishing will render a surface that is very chrome like but far more lasting than chrome.
I do not know what effect, if any, this has on the ductility and tensile strength of the material. I do know that the effect is not enough to be noticed in wire wheel spoke applications.
Worth looking into ???
[/quote]
Electopolishing will change the dimensions of the part. It may be alright for the slide and frame, but you will preferentially polish sharp edges and corners. Also, depending on your electrolyte you can introduce hydrogen into your sample, which can embrittle it. If the piece is polished reasonably well before electropolishing, you can remove only a small layer of material, but I'm not sure I would do this to parts with high tolerances. If you try this, you may want to passivate the surface afterwards as B24H suggests, since that will not change the dimensions, will form a protective oxide film on the surface, and you'll already have the pistol apart. The same facility may be able to do both. An electropolished surface will be clean of oxide until it is exposed to the air, but a thicker oxide provided by passivation will protect it even better.
[This message has been edited by Nick19 (edited April 19, 2000).]
Food for thought.........I have always been turned off by stainless in firearms. Both by the colour and the tendency for stainless to stainless moving parts to gall, even with the presence of some lubes. Before you jump on me, my carry piece is a 686 2.5".
I do have some experience with both high strength and high hardness stainless as used in wire wheel spokes and knife blades. The stainless used in both applications is prone to corrosion. I have had thousands of pieces electro-polished. The electro-polish is much like reverse electro-plating. The piece is suspended in the proper electrolytic solution and currant passed through. The ferrous ( rustable ) portions are removed, molecule at a time, from the surface and from just below the surface; rendering the piece extremely corrosion resistant. If a high lustre is desired, a light buffing after electro-polishing will render a surface that is very chrome like but far more lasting than chrome.
I do not know what effect, if any, this has on the ductility and tensile strength of the material. I do know that the effect is not enough to be noticed in wire wheel spoke applications.
Worth looking into ???
[/quote]
Electopolishing will change the dimensions of the part. It may be alright for the slide and frame, but you will preferentially polish sharp edges and corners. Also, depending on your electrolyte you can introduce hydrogen into your sample, which can embrittle it. If the piece is polished reasonably well before electropolishing, you can remove only a small layer of material, but I'm not sure I would do this to parts with high tolerances. If you try this, you may want to passivate the surface afterwards as B24H suggests, since that will not change the dimensions, will form a protective oxide film on the surface, and you'll already have the pistol apart. The same facility may be able to do both. An electropolished surface will be clean of oxide until it is exposed to the air, but a thicker oxide provided by passivation will protect it even better.
[This message has been edited by Nick19 (edited April 19, 2000).]