JB Welding

[eric1911]

Yes, but you want soft solder as it's more like 500-600 degree working range than actual silver solder that has a 1200-1300 degree working range.

Why the actual silver solder is not preferred?
I think 1200-1300 is still less heat compared to micro or laser welding.

[hermosabeach]

If cosmetic- move one

Clean
Prep re finish.


I don’t understand the desire for a bondo job on a barrel.

Wear on a firearm is character to me. It’s like seeing a Gen 2 Glock and the sides are almost polished from 45,000 draw strokes out of the holster.

Would it be better to sand down the dent if you don’t want to have them welded?

Is it worth heating the barrel to 1,000 and then adding solder?

Is the barrel easily removed? Do you need paste or heat sinks to not cook the action while hearing the barrel?
Can you post a picture of what you are trying to fix?

[hermosabeach]

Skip ahead to 2:28 to see how this gent attaches a band

https://www.youtube.com/watch?v=GWccdgwv5WE

[ar15barrels]

Why the actual silver solder is not preferred?
I think 1200-1300 is still less heat compared to micro or laser welding.

Because you will heat soak a good portion of the part to 1200+ to get good adhesion of the hard solder.
You would have 1/4" or more radius of heat effected zone from the soldering site.
With soldering, you would heat soak all the way through the barrel wall and getting over about 750 is effecting the heat treatment.
If you decide to go that route, make sure you gas purge the bore so you don't get scale build up there as the steel tries to shed it's carbon as you decarburize it with all that heat.

With laser or micro welding, you are NOT heat soaking the whole part as the heat effected zone is very small, like say a 1/32" radius from the weld site.
You won't need to purge the bore or have any problems of decarb in the bore as you won't get the bore surface over 750 degrees.

[ar15barrels]

Skip ahead to 2:28 to see how this gent attaches a band

https://www.youtube.com/watch?v=GWccdgwv5WE

That is soft solder.

[eric1911]

Because you will heat soak a good portion of the part to 1200+ to get good adhesion of the hard solder.
You would have 1/4" or more radius of heat effected zone from the soldering site.
With soldering, you would heat soak all the way through the barrel wall and getting over about 750 is effecting the heat treatment.
If you decide to go that route, make sure you gas purge the bore so you don't get scale build up there as the steel tries to shed it's carbon as you decarburize it with all that heat.

With laser or micro welding, you are NOT heat soaking the whole part as the heat effected zone is very small, like say a 1/32" radius from the weld site.
You won't need to purge the bore or have any problems of decarb in the bore as you won't get the bore surface over 750 degrees.

Thanks for your detailed explanation.
The cost or risk of welding doesn't make sense for a cosmetic touch-up.
I will try JB weld or Devcon epoxy.
If it failed, then it's still a cosmetic thing and I will move on.