Water in Suppressor?

[Prince Yamato]

I just put water in my aac pilot today. It turns the sound from "fup fup" into "fish fish". Not really that much quieter, but different vowel sounds out of the can. I poured a bunch of water from an aquafina bottle and shook it around in the can. No precise measuring here.

 

[rugerdude]

I had also heard a little about suppressors being fired wet, but I had never had the opportunity to test it until a few months ago.

A platoon of guys all shooting M4a1's with KAC suppressors (heavy) and I started mine off with water in it. Nothing measured, just filled and shaken out and I noticed absolutely no difference in volume. The biggest thing was that I had a muzzle signature with all of the water vapor that was being pushed out.

No idea what KAC suppressors use, but by the weight I'd guess it to be all steel. Not sure if this would make a difference.

 

[LiquidTension]

Well the NT4 is pretty loud as far as 5.56 cans go so you might not have been able to tell a difference. Try some water in a better can like an M42k and you can definitely hear a difference. You're right that you do get some vapor coming out the muzzle. You get some in the face and out the ejection port as well. There's a noticeable difference adding water to my old k-baffle .22 can, especially with FRP.

 

[Griffin Armament]

The gas coming out the barrel is hot and contains burning powder. Hot gas expands. Water turns to steam and state change requires thermal energy to be used, so the gas is cooled and that reduces expansion, causing an increase in performance because the suppressor now doesn't have to be as large to effectively allow sufficient gas expansion to occur.

 

[xwray]

Interesting discussion. Can anyone speak to the reason why after the FRP on a a dry pistol can the subsequent shots tend to get quieter? Heat? Residual crap left in the can? What?

 

[Myles]

I use a piece of tape over the muzzle for FRP. FRP is caused by the burning oxygen inside the can - once that oxygen is consumed, the pop is less noticeable. Tape, or a condom, even a cottonball in dry conditions, over or inside the muzzle of the weapon helps that FRP by burning more of the oxygen inside the can before the gasses are expelled. More shots fired equals less available oxygen to be consumed and burned.

Wet lubes inside a suppressor can make it collect more gunk, albeit that it does reduce decibels it will require more cleaning, later. On some proprietary integral rimfire suppressors (Ciener) it can make cleaning an impossible nightmare; they are very quiet, but fire them dry only, please.

An MP5 suppressor that cannot function wet is a mind boggle. I can imagine the troops involved in that fiasco were perplexed (to say the least) that their weapons should not introduce H2O.

 

[Griffin Armament]

LiquidTension

Link to G5 failure for your viewing pleasure.

Interesting link. I did some reading on your link. Couple things seemed noteworthy:

First problem -- the G5 flash suppressor is not HK-416 compatible. We were able to get it to work with spacers (not recommended, but we checked it after a few shots and there was no bullet contact).

So no idea whether the can was aligned or just barely clearing elements of the bore on a jury rigged mounting system. That test was certainly off to a great start.

And no one ever saw the video of a single M4-2000 passing the test. I don't think that was a coincidence.

I measured a suppressor during our testing at 1200F after 120 rounds on a 10.5" barrel. The test calls for 240rds, 10 minutes cooling, cycled 4 times. Stainless steel (tube material of the G5 and M4-2000) loses strength rapidly between 1200F and 1700F. The test parameters are not safe operating conditions by any stretch of the imagination.

 

[LiquidTension]

There's a lengthy thread on silencertalk if you want to talk about the test. The fact remains that Gemtech stated that they utilized a fully welded core, and that is obviously false. This thread is about using water as an ablative. The only reason I posted anything about Gemtech to begin with is when another poster stated that you should not use water in an aluminum can and cited Gemtech as his source, then I posted where Gemtech's own site contradicted him.

 

[Griffin Armament]

Aluminum is fairly corrosion resistant but not corrosion proof. I think it is smart to shoot the water out, and not let it sit for a week till it air dries. [/B]

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As far as the comments about Gemtech:
Dishonesty is not a good way of doing business, and the statement "fully welded core" [ on video at the SHOT show 2007 or 2008 I believe in reference to a core that is not welded at all] was either an employee screwing up (which happens more often all over the world than you would think), or an employee willfully misrepresenting a product. As far as the argument that their product is flimsy, I have no reason to defend them, but I think their product defends itself.

 

[LiquidTension]

I think it is smart to shoot the water out, and not let it sit for a week till it air dries.

Which is what I said back in post 23. Of course I wouldn't use tap water as it often has a bunch of chlorine in it which is bad for aluminum. I always have bottled water at the range anyway.

 

[CZguy]

Aluminum is fairly corrosion resistant but not corrosion proof.

Aluminum corrodes differently than steel or iron. It's rust looks like a white powder.

 

[michael1231231]

Pooling jell

 

[LiquidTension]

Engrish?

 

[Eyesac]

Pooling jell

That is awesome.

 

[Hk Chuck]

Wire Pulling Gel

I think Michael 1231231 ment to say that a, I think it does come in colors but clear is the one you want, clear gel used to pull wire through conduit is a very good abaltive.

 

[Acera]

 

[rjrivero]

I use ultrasound gel. I suppose if you REALLY were worried about acids etching your can, you could mix it with baking soda to neutralize your "firing acids."

 

[10shooter]

I believe that water in the cans produce an acidic residue. What I think is happening is that water subjected to high pressure/temperature and carbon rich gasses quickly becomes acidic. I believe what is made is Phenol also called carbolic acid (C6H5OH). Untreated/unanodized metal is then corroded, each shot will then scrub off the weak metal corrosion leaving a clean spot for the next build up to be scrubbed off. Aluminum readily oxidizes but stops at a very shallow depth unlike steel. Hard anodizing should stop this but the whole can will need it. Now this crrosion isn't like dipping the cans in harsh acids it is a mild acid. Do remember that when your can drys after firing the Phenol residue remains in the can and will not solublize with most solvents used. It needs hot soapy water to disolve and remove the acid. If not then the carbolic acid will reactivate when water is added or in a humid environment.
That all being said I use water in my finish protected wet can. I use 5-10mils and when done they get soaked and shaken with hot soapy water then a carbon cleaner like diesel/gasoline or brake cleaner after a lot of hot water is run through them.