Anyone have suggestions?

I bet you can find several instructional videos on youtube.

Welder's Handbook by Finch describes it fairly well. Practice on scrap will still be required. Way easier if it's thinner sheet metal with both sides the same material and thickness, but for solder or braze to bush a bolt or put on a bolt handle, pre-tinning and fluxing and heating both parts evenly despite different sizes generally requires (me, at least) to practice 4 or 5 times before I can do it right.

I agree with everything posted. At our shop, we frequently silver braze things like Remington bolt handles, action spring tubes and magazine tubes. The tubes require you to braze a thin-walled tube to a relatively heavy receiver. You have to start with heating the heavy part first and getting it up near flow temp. Position the parts so the heat flows up from the heavy part into the thin part. Use plenty of flux. Take a #2 pencil and rub it on anything you don't want solder to stick to. This will speed cleanup immensely. Have a rock solid jig to hold the parts in position. When you heat the parts they will move unless restrained.

One thing we found out years ago with various emplyees

If you are Red-Green color blind then you will not be able to see the color shift in the melting flux to the point the solder will start to flow
And you will overheat the joint and make a mess

Just a heads up

J Wisner

Same as soft soldering..
Clean the joint well,
Never heat the fluxed joint directly, heat the metal below it/around it and let the heat migrate to the fluxed joint.
Otherwise you will most likely burn/over heat the flux (it turns black and is worthless). Then you have to let the parts cool, separate, clean up and start over.

As the flux heats up, it will bloom up and puff up and then as it gets hotter yet it will settle down and form a clear glass like coating on the parts.
At this point you are almost at the point where your Hard Solder or Brazing rod will melt and flow on the fluxed surfaces.

You need a Red Heat for either to flow, but again down over heat and burn off that flux.

Carefully touch the tip of the solder wire or the brazing rod to the fluxed joint and when the temp is right,,either will easily melt and flow right into and around the joint for you.
It helps to swipe the solder wire or rod thru the torch flame quickly to warm it and then stick it into the flux to make it stick to the tip of either. That small added flux helps when adding the solder/Braze to the joint.

Let the completed job cool on it's own, don't quick cool by quenching or use compressed air.

That flux will cool as a hard glass coating. It can be carefully chipped off pretty easily or if the part is small throw it in a container of boiling water and let it go for a few minutes and it'll disolve away.

The scrubbing of areas with a lead pencil works to keeps solder off of those no matter if soft, hard or brazing.

Add only what you need for a neat complete job.
Globbing more onto the joint doesn't make it that much stronger and certainly isn't pretty.

I

I have no need for brazing; I do not work on shotguns, and TIG weld everything that needs it. Even Rem 700 bolt handles that guys break off; I weld them back on.
So, first determine what you intend to join.

Agreed that brazing has a somewhat limited applicaion in modern firearms. Years ago, I did a lot of work for an antique arms dealer on the East Coast. Was going to weld a sping, but quickly advised that it MUST be brazed to period correct repair.

So....if your business takes that turn, good brazing is valuable and in demand.

Good luck

Craftsman Oxy-Acetylene Welders manual has some decent info. Readily available from online book sellers or on ebay for less than $15 usually.

I've got a book somewhere from one of the welding gas suppliers that I got in welding school, don't remember which supplier it was from. Maybe Linde.

Contact Lincoln Electric.
They have books on every phase of
metal joinery at very fair prices.

OR do it the MODERN way: ask Google online!
George

If you really want to learn something, it's all on Youtube; no one reads books any more.

quote:

Originally posted by dpcd:
If you really want to learn something, it's all on Youtube; no one reads books any more.

...or can't read.