? O/A technique 4 building up bronze when brazing

[Joel_BC]

I'm pretty good with basic brazing technique using an O/A torch, brazing rod, and flux. What I want to learn how to do is build up a greater mass of bronze (or "brass") when I want to, when making a joint - usually between steel parts. One aspect seems to be to use a larger-diameter rod.

But my real problem seems to be that after I've laid down the basic joint, I'm melting the joint bronze as I try to add more material from the rod. The bronze seems to liquify too readily and just runs. I want to be able to build up a hefty joint sometimes, a real wad that I can later shape by grinding down a bit, if need be.

I'm sure that I could bumble toward the proper technique for this on my own, but I thought a few hints from the more experienced might make the process less painful and time-consuming. LOL

Thanks.

[Bearfootfarm]

You might try running your first beads, then letting it cool and switch to a smaller tip for the "built up" portions

[Ray]

I'm sure you know the only time you really need the extra heavy braze is under repeat impact conditions. Build up is just a practice thing like everything else. If you have lots of gas get some old coat hangers and practice with them. once you can do it with coat hangers, or any old non-galvanized wire, you can buy cheap welding wire at the store too, just like brazing rods, you can paint the Mona Lisa with brazing rods, plus you can repair alot of steel things with wire you never even knew. best wishes ray

[farminghandyman]

It is heat control, I use to build up a Lot of Irrigation gear box shaves that had had there seal surfaces destroyed, and if you turn your heat down and then concentrate the heat on the rod one can dab in the bronze and built it up as long as the base is up to temperature, I keep the base hot enough to keep the bulk of it just below melting, and the area where I was working where it was more like a past, and with just a flick of the flame one could puddle the bronze for the new added material would flow and puddle and become part of the build up,

I would suggest to turn down the tip or change to a smaller one,

as one know brazing and welding are different but it is all about heat control and where you putting the heat, the base metal the puddle or the rod, and depending on what you want to do and were and types of metal and thickness it all depends, some times it is moving the tip to various areas and even removing it for a few seconds to keep the temp where you want them

hope that makes sense,

[Joel_BC]

Originally Posted by Ray

If you have lots of gas get some old coat hangers and practice with them. once you can do it with coat hangers, or any old non-galvanized wire, you can buy cheap welding wire at the store too, just like brazing rods, you can paint the Mona Lisa with brazing rods, plus you can repair alot of steel things with wire you never even knew. best wishes ray

Thanks, Ray. But sounds like you're talking about both brazing and welding, Ray ("coathangers"). I'm asking about brazing only. Like for when you want to join dissimilar metals - e.g., stainless steel to mild steel, mild steel to high-carbon steel, etc. Or when you just want to work at lower temperature to create the joint. Then, brazing (or hard soldering) is the ticket.

I just want to get better at making thicker braze joints.

[Ray]

I really ment to practice with the coat hangers not that they would be exactly the same. I have many torches that I use but,mostly the last few years My welding torch is an DHC 2000 with all the attachments that are made for it. if you get everything there is for it its fairly expensive but it does alot. from welding aluminum on up. I've worked with all kinds of torches, all my life many ways, cutting and welding, heating, and brazing many things. I think you would like the Henrob 2000, you can cut thin material nearly as well as a plasma without warp and weld anything except titanium. with practice. you can weld a soda can cut in half back together. Thats how fine of flame you can control.
With torch control you can easily control braze joint build up. maybe you want to switch to a smaller tip to allow for cooler all over control, this will allow you complete control, depending on what your brazing.
Today I was Brazing a diesel fuel filter canister inner threaded stem core that broke back together. its like a big metal straw, the sides thick as your thumb nails threaded inside, 3/8 in. hollow. when I braze I usually melt the braze into the metal on both sides and do not use it like a solder. Its just the way I was taught 40 years ago. The only thing I solder with is silver solder, and lead solder., best wishes, ray