Soldering on a muzzle brake...

[virulosity]

For some reason I can't get the solder to stick. I am using a wire wheel to prepare the surface, I then use a propane torch to heat the barrel to near glowing hot. I then dip a high temp solder in flux and apply to the surface, but it just runs right off. Any suggestions?

[JHC]

For some reason I can't get the solder to stick. I am using a wire wheel to prepare the surface, I then use a propane torch to heat the barrel to near glowing hot. I then dip a high temp solder in flux and apply to the surface, but it just runs right off. Any suggestions?

Try brushing the flux onto the parts, also you might need more heat (MAPP)

[virulosity]

Tried brushing too. Maybe I will have to buy a MAPP bottle.

[Ledbetter]

You should clean it with acetone or ethanol after brushing and before fluxing.

[chuck762]

Have you removed all the finish and have bare metal? Parkerizing or bluing will stop the solder from sticking. Getting the finish from inside the threads on the muzzle device is the hardest part. If you don't the solder may stick to the barrel threads but the brake will still come off fairly easily.
I used to use the brownelles solder past when i was soldering muzzle thingies on but now I pin and weld it. Much easier and you don't heat the barrel so much.

[ar15barrels]

I then use a propane torch to heat the barrel to near glowing hot.

You do realize that you have completely annealed that barrel right?
That's why I pin and weld.

To silver solder:
Clean both mating surfaces of all finish.
De-grease and leave dry.
Apply flux where you want the solder to flow.
Join the two parts, clamping them together if necessary to hold them together.
Heat up both parts to 1200+ degrees.
A mapp torch is usually required.
Add the solder to the fluxed area and it should "wick" into the joint wherever you put flux.

[ViPER395]

I'm curious as to why people weld and solder their barrel attachments.

Other than making the legally required 16" length, I can't see it.

[Utha Schleigle]

Tried brushing too. Maybe I will have to buy a MAPP bottle.

Be sure to buy a mapp torch head when you get your bottle of mapp. A propain head will melt in your hand.

I going to sliver braze because my two parts are made out different materials. Machined steel and cast (not sure) ?????

If I was soldering some thing threaded, I would prepare surfaces apply solder and flux paste combo. Screw it on and apply heat.

I have to get solder paste for a shot gun project and Brownell's sells a thick and chucky anti running for parts that are not closely matched and/or you want no runs.

One book said to mask and use a cork or rubber stopper / modeling clay to protect unwanted areas from sand blast.


Has chapter for silver soldering muzzel attachments - push on and threaded. Also chaptor for other silver solder applications.

Above book had a lot of great advice on soldering was this one. It said to use graphite from a pencil and carpentor pencil to give a crisp straight line to your soldering use a ruler at the points where you you want the solder to stop and not accidently stick. **** After applying graphite to "protected" areas DO NOT BLOW on any graphited area to remove excess powered graphite. DO NOT BLOW OR PUFF, because you move some graphite into your want to stick area and will have reprep stick area and getting graphite off/out completely is very tuff.****

I got a sand blaster to prepare metal, butt another source said sand leave the parts very dirty and to clean them with thinner or acetone and let completely dry before applying flux. I am useing 30grit sand 50lbs for $6. What is the best media to sand-blast with for this and painting.

Blind pinning and four pot welds is the industry standard if you never want it to come off or if you are meeting any regulatory laws State/Fed.

[Pulsar]

If the muzzle brake is threaded already, why are you soldering, or pinning? I don't know of any law that says you have to pin or solder a muzzle brake (unless your going for 16" bbl length) or it's on a pistol. If the threads are good there is no real reason to do it mechanically, if your that worried, a little low temp locktite should suffice.

Just curious.

[virulosity]

This was for a project that needed 922r compliance, but I am also trying to fill the notches left in the barrel from where a grenade launching attachment used to be. Is there a better way to do this? I am just trying to fill the little half moon dowel channels in the barrel. The only reason I am trying to solder them is because that is what I have access to at the time.

[motorhead]

solder probably won't fill the holes. you can't build up solder like you can with a weld. you just get a bigger pool of solder. brazing might work but it'll never match the bbl. finish. you're probably stuck with either weld and grind or live with it.

[Ak47owner]

I am a structual steel welder and i do this alot. What you have to do is get both pices to be joined RED then add your filler rod after heating let it cool naturally. Dont quench it in water.

[CALI-gula]

To silver solder:
Clean both mating surfaces of all finish.
De-grease and leave dry.
Apply flux where you want the solder to flow.
Join the two parts, clamping them together if necessary to hold them together.
Heat up both parts to 1200+ degrees.
A mapp torch is usually required.
Add the solder to the fluxed area and it should "wick" into the joint wherever you put flux.

Anyone ever "sweat" a plumbing joint? Same process that you've described. That is exactly what I was thinking when I read the first post.

.