Great find, thanks for posting this!

Wrong
http://i129.photobucket.com/albums/p203/CHRIS65-IL/ATF_Chp2_Rifle_Image1.jpg and welding isn't even mentioned

And the entire booklet http://www.atf.gov/firearms/nfa/nfa_handbook/chapter2.pdf

Tagitytoooo

Like a lot of what we do, SS will damage a barrel if done incorrectly. Just follow the simple guidelines and you won't have any issues.
1. HEAT STOP paste. Use liberally. I have seen some folks get real paranoid and glob Heat Stop on a bore patch and coat the inside of the barrel. Not necessary but hey, if it makes you feel better....
2. Good quality SS, preferably in paste form with flux mixed in. Do not glob it on, apply to the threads only.
3. Apply heat preferably from a MAPP or even better, an OXY/'MAPP. The trick is to get it up to the appropriate temperature as fast as possible. Put heat on the FH until you see the solder flow at the seam between the FH and the barrel.
4. Remove heat immediately, put the barrel down to cool.

To remove, use HEAT STOP, heat the FH and turn it until it spins off. Wire brush the threads. Done.

On pin jobs, you usually have to destroy the FH by splitting it wih a dremel. Done that a few times, easy to do but watch the depth of your cut or you'll be cutting your barrel as well.

I guess what I'm missing here is how much importance you're putting into removal of the FH. The point is to make it a permanent part of the barrel so you don't run afoul of ATF regulations.

I am having trouble getting the solder to work.

I am using jeweler's paste with flux already mixed in. After applying it to the threads and screwing the FS on, the solder gets pushed to the back. I heated it up, and I was able to fairly easily break the FS loose with a wrench. The Solder ran, and the crush washer was the only thing perm attached.

Any recommendations on how to get the Solder to stay in the threads of the barrel? Should I drill or cut out a couple of small holes in the threads to get he solder to stay?

Thanks for your help.

That is not legal.

i will be using the SS method in the next week. thanks to all the conversation before, i'm feeling pretty confident. i'll post/edit when i have it finished.

I've heard that Silver Solder can corrode a barrel over time and that it isn't recommended... Anyone else hear anything like that?

Can anyone post a link the the appropriate MAPP torch? I have a propane torch head laying around which I used to braze some copper pipe together last year, would that work if I got a MAPP cylinder?

Thanks!

This is what I use with good results:



Got mine at Lowes or Home Depot... can't remember which.

Here's the last one I did. Phantom timed with a crush washer on a Colt 727 upper. Brownells paste. MAPP/OXY torch. Brownells heat stop.

No.

There are plenty of hundred year-old SxS shotguns in excellent condition around. Most double barreled shotguns, ribs, (and even some sights) are assembled with silver solder.
Silver solder is very inert.


ETA: If you use flux and get sloppy removing the residue (or just plain forget), that can be kinda nasty stuff.

Will this work on a supressor. If it does anyone got any pics? I guess you would just heat up the base of the surpressor?

Good thread!

I'm gonna buy an 11.5" barrel and SS my Gemtech onto it. Suhweet! A 1-tax suppressed sbr!

The post a few slots above, listing various temperatures for various colors is good info.

The MAPP approach is good because it's next to impossible to get steel hot enough with a MAPP cannister to alter it's metalurgical properties, provided you don't quench it in water to cool it. Repeat - do not quench; just let it cool by itself.

Faster heat transfer is optimal, but not critically essential. Any changes you make to the steel of your barrel, FH, or quality suppressor while using MAPP gas will be purely cosmetic, not metalurgical. A faster heat session with an oxy/acetylene welding torch simply enables you to focus the heat-ramp better on the work area. Since a MAPP torch will take longer to get the work area up to heat, more of the barrel and can will get hot, and potentially discolor. I'd think this would be more of an issue for stainless barrels than parked barrels.

The heat paste or a wet rag is the solution to controlling heat migration.

I guess it's possible that some cans have silver soldered caps. If so, no big deal as long as you don't unscrew the can during the brief peak heat cycle, which would be counter to what you're doing anyway.

Soldering is actually quite easy.

Clean both surfaces using brushes and solvent. Rinse well with a spray can of starter fluid or carb cleaner. If you use starter fluid, be sure it's the variety that does NOT contain a lubricant. Some starter fluid brands include a cylinder lube in their formulation. This would give you fits. You want pure ether. Walmart brand $1.39 carb cleaner is a great non-residue degreaser.

A true solder paste that contains both flux and solder is ideal. Easy to find. See earlier posts. Stir it well to get a nice working consistency, and put a nice light coat on both threads. Assemble. You want to have a slight ring of it pushed up around your crush washer or can once threaded on completely. If it's a huge glob-ring, you used too much. I'd disassemble it, wipe it clean, and do it again with less paste this time.

The slight ring of paste will be your tell-tale.

Cut 2 strips of "t-shirt" material 3" wide by 6" or 9" long or so. Get them generously damp, but not dripping. Wrap the barrel and can leaving only a half inch or so of the barrel and of the can exposed. A wrap of three layers will be sufficent. Use tape on the far end of each to hold them in place and keep them from unraveling. Find an eye-dropper or pediatric tylenol medicine dropper and some water.

Clamp the gun so that you can circle the flame uniformly on all sides of the joint. Heat the joint aggressively and uniformly. Use the eye dropper to re-wet the wrap as necessary. Yes, you will char the edges of the wrap, but keep it damp as you go.

The solder component of the tell-tale will melt right away when you start to heat.

But you're still a long way from melting the solder. Just stay on it, heat uniformly, with a slight extra-heat bias for the part of the work area that is easiest to see. Watch the solder. At some point, the solder in the bias area will suddenly melt and wick in to the threads, nearly vanishing. Immediately continue a slow cylce around the joint until you've chased that effect all the way around the barrel. This last step should take less than 5 seconds. Turn off torch, check to see that your workbench is not on fire, place a final drop or two of water on each wrap edge, and have a beer. When the work area is cool enough to touch, test your job by attempting to uncrew the FH or can. It will either feel like a rock-solid single piece, or it won't. On a parked steel, CLP will mask most of the evidence of heat on the work area.

The chalk on the work area is a good idea for catching melting solder so it doesn't leave a residue.

While heating, use water drops from the eyedropper only on the cloth wrap, not the work area.

If the solder beads up and does not flow into the joint when it melts, agrressively apply heat right to the joint at that location for 8 seconds. If it doesn't flow in, you weren't clean enough. Stop. Let it cool. Start over. Remember - cleanliness is next to Godliness. You want no dirt, no oil, no grease, no powder residue, no nothing. Just clean bright dry steel. Degrease the barrel and can near the work area so that hot oils don't migrate with heat into your work area.

Oh yeah - I'll post my own results once I've actually done it.

BTW - I'm pretty sure that silencers are only legal in WA state if you DO NOT attach them to a firearm. Better check into that.