Silver Solder DIY

[Armati]

I was searching the pages and discovered that we did not have good silver solder thread.

It seems to me that silver solder may be the easier method for the home gunsmith to permanently attach a muzzle device.

I was wondering what other peoples experience have been with this technique? I have done a few google searches and Youtube has a few good tutorials on silver solder.

With our hobby, one of the big concerns is protecting the original phosphate finish of the work. I will be using Brownell's Heat Stop heat control paste to protect the finish outside of the immediate work area. Anyone have experience with this product?

I am not using a crush washer but rather the flat washer supplied with the B.E. Meyeres Flash Eliminator. I will torque it to 20 ft lbs then apply Wolverine Ultra Flux to the flat washer and the joint on both sides of the washer.

Bernzomatic sells a little MAPP and O2 torch ( Cutting, Welding and Brazing Torch Kit P/N: OX2550KC ) that should provide plenty of heat and has a very fine torch head that should be able to concentrate the heat into a very small area. My intent is to apply the heat only directly to the flat washer.

According to everything else I have seen, I should burn off the bulk of the flux then heat the washer to a dull red. I will then apply the tip of a 1/32" Silvaloy 355 wire to the washer and the flux should carry the solder into the joints between the washer and barrel, and the washer and the muzzle device.

After cleaning and polishing the work, I should end up with a nice silver ring around the end of the barrel.

Did I miss anything? I should be doing this job next week end and I will post the results here. So please, if anyone has some experience in this area please share it. Thanks.

[bkb0000]

i've never actually seen where the atf spells out exactly how to use high temp silver solder, but the only method ive ever seen used was to solder the threads, not just a ring around the outside. most of the ones i've seen even involve grinding a trench into the threads, to allow the silver to really flow in

[m-w]

I used a paste type high temp silver solder to attach the muzzle brake for my FAL back when the law insisted on it. It worked well and was a very simple process but I was a bit nervous about applying that much heat around the barrel surfaces.

[Sidewinder6]

I have done a lot of silver solder work however, I will say, not much on firearms. We were teaching custom tool making.

The risk associated with this sport is altering the temper of the metal you might be soldering to. We worked mostly with spring steel that has the similar risk of loosing its tensile strength.

In order to counter this, we made sure we did not overheat tempered the metal to a glow and used a good paste flux. (You can tell you are overheating the metal if the flux boils and turns black.)

We use a quart of motor oil and poured it into a dipping pan of the size to submerge the parts we are heating. No water here except to drink. Not cooling OK?

You will wish to have a third hand because you have 2 or more parts you want the solder to flow to, then the torch and another for the solder and flux. You get the gist.

Find yourself some scrap to learn and try this out before you put a torch to a firearm because otherwise the effect would be like substituting a plastic piece on a firearm part.

FWIW, if your working on things like sights, I hear JB Weld works better than I would have ever given credit for.

I dont know if this helps but I will be happy to elaborate on what we did. I am not sure there are many 'Smiths' who endorse this for gun barrels or other high pressure parts. Some may ring in here on the metallurgy with better advice.
I am not saying whether you should do it, I am only saying how to do it.