Hard chrome plating baffles for abrasion resistance at home

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Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Sat Feb 17, 2018 6:17 am

Would it work, as in give greater abrasion resistance, to a suppressor if you hard chrome plated the baffles using this http://www.caswellplating.com/electropl ... 1-gal.html home plating kit and then afterwards bake it for 8 hours at 415 degrees f?
The baffles would be 17-4 ph h1150 stainless steel baffles from zmachineworx.
Is there anything that I’m missing here in regards to safety? I realize there’s hydrogen embrittlement but baking takes care of this and chrome lining is safe for the much higher temperature and pressure taking rifle barrels. Adding a layer of fairly thick chrome with a Rockwell hardness of 68 should definitely reduce pitting.
I’d also like to change the heat treatment, from h1150 to h900 but I’m unsure how. I know you need to anneal the parts but I don’t know how to get them to 1900f, and that’s in a solution I believe.

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by ECCO Machine » Sat Feb 17, 2018 12:30 pm

I'm inclined to think that the combination of thermal expansion, pressure and shock would cause the plating to fail, particularly with a home application type. The inside of a suppressor is a very different environment from the inside of a barrel.

If it were feasible, major manufacturers would be doing that with cheaper metals rather than spending the money on Inconel and Stellite.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Sat Feb 17, 2018 3:45 pm

ECCO Machine wrote:I'm inclined to think that the combination of thermal expansion, pressure and shock would cause the plating to fail, particularly with a home application type. The inside of a suppressor is a very different environment from the inside of a barrel.

If it were feasible, major manufacturers would be doing that with cheaper metals rather than spending the money on Inconel and Stellite.
But a barrel experiences more pressure, temperature and direct friction with the projectile so shouldn’t it last much longer on baffles?

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by John A. » Sat Feb 17, 2018 6:04 pm

Hannibalbarca wrote: But a barrel experiences more pressure, temperature and direct friction with the projectile so shouldn’t it last much longer on baffles?
That was along the same thoughts as I was having.

With that said, I have seen guys that have used chromed nickel plated fender washers in their 22 cans.

It doesn't really help fight lead deposits or cleaning though.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Sat Feb 17, 2018 6:18 pm

John A. wrote:
Hannibalbarca wrote: But a barrel experiences more pressure, temperature and direct friction with the projectile so shouldn’t it last much longer on baffles?
That was along the same thoughts as I was having.

With that said, I have seen guys that have used chromed nickel plated fender washers in their 22 cans.

It doesn't really help fight lead deposits or cleaning though.
I only care about the abrasion resistance aspect, though corrosion resistance is good too.
My 22 will be formed freeze plugs, zinc plated, ill have to somehow remove the plating if I decide to do this.
My concerns are if the kit will give me the equivalent of mil spec QQ-C-320b plating, hydrogen embrittlement and adhesion. I believe they do a pre plating of nickel first and then chrome.

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Sat Feb 17, 2018 6:31 pm

An issue I see with this is clearance, if you’re depositing .003 inches of chrome that might make the baffles too big to fit.

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by ECCO Machine » Sat Feb 17, 2018 11:23 pm

Hannibalbarca wrote:
ECCO Machine wrote:I'm inclined to think that the combination of thermal expansion, pressure and shock would cause the plating to fail, particularly with a home application type. The inside of a suppressor is a very different environment from the inside of a barrel.

If it were feasible, major manufacturers would be doing that with cheaper metals rather than spending the money on Inconel and Stellite.
But a barrel experiences more pressure, temperature and direct friction with the projectile so shouldn’t it last much longer on baffles?
Pressure, yes, but not the kind of shock, and definitely not the temperatures. Fire 10 rounds through your AR as fast as you can, the barrel is warm to the touch. Your can, however, will burn your hand.

Barrels are also much thicker than baffles or housings, so a lot more rigid backing for that plating. Also far less surface area for that pressure and heat to act on.

A machine gun barrel can take several hundred rounds before failure. Suppressors, nowhere near that:

https://www.youtube.com/watch?v=BczhT1ByrXA
Last edited by ECCO Machine on Sat Feb 17, 2018 11:32 pm, edited 1 time in total.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by ECCO Machine » Sat Feb 17, 2018 11:31 pm

Double post
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hatchetjoe » Sun Feb 18, 2018 12:36 am

If chrome plating had advantages some mainline MFGs would be offering it by now.

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by jlwilliams » Sun Feb 18, 2018 12:42 pm

I would think that with 17-4ph baffles you should be pretty good without adding plating. That's a fairly tough material. It might be a benefit on a mild steel part, but even that's questionable if the juice would be worth the squeeze.

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by T-Rex » Sun Feb 18, 2018 1:53 pm

Seeing that you're blast baffle is the only face to really need such treatment, it would make sense to just hard face it with some Tig beads of more apt material. I know a member here has already done this.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Sun Feb 18, 2018 5:30 pm

T-Rex wrote:Seeing that you're blast baffle is the only face to really need such treatment, it would make sense to just hard face it with some Tig beads of more apt material. I know a member here has already done this.
What would that do to the surface where it was welded?

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by T-Rex » Sun Feb 18, 2018 6:43 pm

Hannibalbarca wrote:What would that do to the surface where it was welded?
It would lend the properties of the stronger materials, to the base metal.
Make a baffle from X metal and face it with Stellite rod. You wouldn't need to spend as much for the stock material or need to worry about machining the Stellite.
17-4 is relatively cheap and you'd probably need but 1 rod of the Stellite.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Sun Feb 18, 2018 7:38 pm

T-Rex wrote:
Hannibalbarca wrote:What would that do to the surface where it was welded?
It would lend the properties of the stronger materials, to the base metal.
Make a baffle from X metal and face it with Stellite rod. You wouldn't need to spend as much for the stock material or need to worry about machining the Stellite.
17-4 is relatively cheap and you'd probably need but 1 rod of the Stellite.
So just do the face of the cone? What about the interior?
Also, I don’t have any experience with welding nor do I own the equipment for it, so would it be easy to do or would I risk the chance of making the baffle weaker?

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Sun Feb 18, 2018 8:56 pm

Hannibalbarca wrote:
T-Rex wrote:
Hannibalbarca wrote:What would that do to the surface where it was welded?
It would lend the properties of the stronger materials, to the base metal.
Make a baffle from X metal and face it with Stellite rod. You wouldn't need to spend as much for the stock material or need to worry about machining the Stellite.
17-4 is relatively cheap and you'd probably need but 1 rod of the Stellite.
So just do the face of the cone? What about the interior?
Also, I don’t have any experience with welding nor do I own the equipment for it, would it be easy to do or would I risk the chance of making the baffle weaker?

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by T-Rex » Mon Feb 19, 2018 10:01 am

Hannibalbarca wrote:So just do the face of the cone? What about the interior?
Obviously, all surfaces would see a benefit, but only the face would truly need it.
Hannibalbarca wrote:Also, I don’t have any experience with welding nor do I own the equipment for it, would it be easy to do or would I risk the chance of making the baffle weaker?
This is not a difficult task to accomplish, but it's also not for a beginner. You'll need to create many rows of weld beads while maintaining size and overlap. Welding can always weaken the base metal. However, proper welding techniques, learned from experience, can help prevent or at least not exacerbate such pitfalls.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by BinaryAndy » Mon Feb 19, 2018 9:19 pm

ECCO Machine wrote: Pressure, yes, but not the kind of shock, and definitely not the temperatures. Fire 10 rounds through your AR as fast as you can, the barrel is warm to the touch. Your can, however, will burn your hand.

Barrels are also much thicker than baffles or housings, so a lot more rigid backing for that plating. Also far less surface area for that pressure and heat to act on.

A machine gun barrel can take several hundred rounds before failure. Suppressors, nowhere near that:

https://www.youtube.com/watch?v=BczhT1ByrXA
So you're saying a suppressor experiences more shock, and higher temperatures, than the BORE of a rifle barrel?! Remember, we're talking about coatings here. I promise you the chrome lining in a rifle barrel experiences dramatically higher surface temperatures, impact stress and thermal shock than almost anything you can inflict on a suppressor. The coating in the bore doesn't care how hot the outside of the barrel gets. Everything that goes through a suppressor goes through the throat of the barrel at much higher pressures and temperatures. True, suppressor parts do deflect more than a barrel, but that's the only way in which a suppressor is a harsher environment than a rifle bore.

The OP was asking if chrome plating the baffles would give them greater abrasion resistance. Answer: of course it would. You would be coating the steel with a metal that's harder, more abrasion resistant and more heat resistant than steel, so of course you would get better abrasion resistance. The fact that major manufacturers don't do this simply means that there's some reason not to or a better option available to them, not that it won't work. I can tell you why I'm not using chrome: it's too thick and not consistent enough to use on threaded components; there are other coatings that outperform chrome's wear, corrosion, adhesion and cleaning properties; and it's not black.

If you're going to try a DIY plating for silencer parts, while chrome will do what you want, I think you'd be better off with electroless nickel. I know Caswell also sells a kit for what they call electroless cobalt; if that is actually electroless cobalt, and it works as well as they say it does, then that should be better yet for our purposes.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by propeine » Tue Feb 20, 2018 12:20 pm

Hannibalbarca wrote:
Hannibalbarca wrote:
T-Rex wrote: It would lend the properties of the stronger materials, to the base metal.
Make a baffle from X metal and face it with Stellite rod. You wouldn't need to spend as much for the stock material or need to worry about machining the Stellite.
17-4 is relatively cheap and you'd probably need but 1 rod of the Stellite.
So just do the face of the cone? What about the interior?
Also, I don’t have any experience with welding nor do I own the equipment for it, would it be easy to do or would I risk the chance of making the baffle weaker?
You won't be hardfacing if you have no welding experience.

One option would be sending them out for nitride.

I think blacknitride.com has their SOT.

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by BinaryAndy » Tue Feb 20, 2018 12:56 pm

propeine wrote: I think blacknitride.com has their SOT.
Can confirm. Can also recommend.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by cdhknives » Tue Feb 20, 2018 3:51 pm

The first thought in my mind was tradeoff between plating and just making the part thicker. For a form 1 with lathe turned parts, I'd just make the blast baffle thicker to account for wear. An extra few thousnadths of 17-4 vs. the same thickness of plating? Some difference but enough to be worth the effort? Not to my mind, YMMV. With purchased internals where you can't customize, well, that is a bit different but for the money being spent to get set up to plate maybe sending a 'complete form 1 suppressor' serialized tube to someone with the license to rebuild is a better use of your $$$. There are several here that can do that for you. No working with all the hazardous materials of a plating system either.

I looked into hardfacing (repairing an old anvil with a badly pitted/gouged top) with a career professional welder. It was dang expensive and not very smooth...not something I'd recommend on a machined part unless you were willing and able to machine it after buildup. Even the best welders are not going to be able to stop the weld at the proper diameter for your tube so you're going to have a gap or overhang to be ground/filed/cut off.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by propeine » Wed Feb 21, 2018 2:29 pm

BinaryAndy wrote:
propeine wrote: I think blacknitride.com has their SOT.
Can confirm. Can also recommend.
Thanks Andy. Yes I would also recommend them. Those guys are awesome

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Wed Feb 21, 2018 6:40 pm

BinaryAndy wrote:
ECCO Machine wrote: Pressure, yes, but not the kind of shock, and definitely not the temperatures. Fire 10 rounds through your AR as fast as you can, the barrel is warm to the touch. Your can, however, will burn your hand.

Barrels are also much thicker than baffles or housings, so a lot more rigid backing for that plating. Also far less surface area for that pressure and heat to act on.

A machine gun barrel can take several hundred rounds before failure. Suppressors, nowhere near that:

https://www.youtube.com/watch?v=BczhT1ByrXA
So you're saying a suppressor experiences more shock, and higher temperatures, than the BORE of a rifle barrel?! Remember, we're talking about coatings here. I promise you the chrome lining in a rifle barrel experiences dramatically higher surface temperatures, impact stress and thermal shock than almost anything you can inflict on a suppressor. The coating in the bore doesn't care how hot the outside of the barrel gets. Everything that goes through a suppressor goes through the throat of the barrel at much higher pressures and temperatures. True, suppressor parts do deflect more than a barrel, but that's the only way in which a suppressor is a harsher environment than a rifle bore.

The OP was asking if chrome plating the baffles would give them greater abrasion resistance. Answer: of course it would. You would be coating the steel with a metal that's harder, more abrasion resistant and more heat resistant than steel, so of course you would get better abrasion resistance. The fact that major manufacturers don't do this simply means that there's some reason not to or a better option available to them, not that it won't work. I can tell you why I'm not using chrome: it's too thick and not consistent enough to use on threaded components; there are other coatings that outperform chrome's wear, corrosion, adhesion and cleaning properties; and it's not black.

If you're going to try a DIY plating for silencer parts, while chrome will do what you want, I think you'd be better off with electroless nickel. I know Caswell also sells a kit for what they call electroless cobalt; if that is actually electroless cobalt, and it works as well as they say it does, then that should be better yet for our purposes.
I called caswell and the electroless cobalt only has a Rockwell of 40, a significantly lower surface area for the coating so I’m not even sure I’d be able to coat all the parts and its only .001 thick.

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by ECCO Machine » Thu Feb 22, 2018 1:54 am

Hannibalbarca wrote: I called caswell and the electroless cobalt only has a Rockwell of 40, a significantly lower surface area for the coating so I’m not even sure I’d be able to coat all the parts and its only .001 thick.
That's not even as hard as 17-4 H900 (Rc 45)

If it's maximum hardness of the blast baffle you're after, just make the thing from 0-1 tool steel, heat treat it at 1,600° F and leave it glass hard. That'll give you an Rc of about 63-65. Hard chrome (done right) is 65-68 Rc. You could also use M42 cobalt and heat treat at 2,150°F for Rc 68-70, and the stuff stays hard at very high temperatures, but it's expensive and difficult to work with.

Truth is, though, unless you're actually running full auto and lots of it, it's gonna take you a really, really long time to see any appreciable wear on a sufficiently thick 17-4 H900 blast baffle.
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Re: Hard chrome plating baffles for abrasion resistance at home

Post by Hannibalbarca » Thu Feb 22, 2018 1:51 pm

ECCO Machine wrote:
Hannibalbarca wrote: I called caswell and the electroless cobalt only has a Rockwell of 40, a significantly lower surface area for the coating so I’m not even sure I’d be able to coat all the parts and its only .001 thick.
That's not even as hard as 17-4 H900 (Rc 45)

If it's maximum hardness of the blast baffle you're after, just make the thing from 0-1 tool steel, heat treat it at 1,600° F and leave it glass hard. That'll give you an Rc of about 63-65. Hard chrome (done right) is 65-68 Rc. You could also use M42 cobalt and heat treat at 2,150°F for Rc 68-70, and the stuff stays hard at very high temperatures, but it's expensive and difficult to work with.

Truth is, though, unless you're actually running full auto and lots of it, it's gonna take you a really, really long time to see any appreciable wear on a sufficiently thick 17-4 H900 blast baffle.
I’m unable to machine my own cones and am will be using zmachineworx 17-4 cones in h1150 condition though I want to anneal them and get them to h900 though I can’t do that since I don’t have an oven.

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Re: Hard chrome plating baffles for abrasion resistance at home

Post by BinaryAndy » Thu Feb 22, 2018 2:23 pm

I don't think you talked to the right person about the cobalt. Electroless nickel is around 65 HRC, and cobalt is supposed to be harder. In any case, electroless nickel and salt bath nitriding both outperform chrome in nearly every way.

I would not recommend reworking the heat treatment.
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