welding brass?

I can't think why anyone would want to. Brass doesn't like being worked hot - it's mechanically fragile when hot and the melting point is too low for comfort, relative to any likely filler rod. Because it has good conductivity you have to pump plenty of heat in, but get that temperature just a little too high and you've made a blowhole.

I'd silver solder them instead.

If it's only for RF shielding, soft solder would be the way to go. If you can make them with good sized overlaps on the joints they will be reasonably strong.

A product called Solder-It now goes into my toolbox and workbench. Paste hypodermic dispenser, great flux, probably about 6 percent Silver, very, very strong, easy to use.

MUCH stronger than the wimpy 2 or 3 percent stuff we used to get at Rat Shack. Seen in many hardware stores... / just my

jtaylor wrote:

I tried tigging brass several years ago with a brazing rod that I'd sanded all the flux off of. It didn't work as the zinc cooked out of the rod making a mess as Mr. Billington noted above. I went to the National Welders local shop, told them what I was trying to do, and they sold me the correct rods. Worked just fine after that, but you've really got to turn up the amps as the brass was very good at conducting the heat away.

Garrett Fulton

I once used one like this. It was the giggest PITA I ever had. Must have been a different brand.

I'll shop for that.

I just silver soldered the case. And it was the pain expected. This is something that cries for a jig and a fan-burner (many little flames, not just one big).

Nick

I tried OA with some scrap. And scrap came out! :-) I have welded Al with OA. But Al is easy compared to brass.

I'll stay with silver solder, (not soft soldering) because it has to withstand quite some mechanical load, it is to big and doesn't have enough overlaps. Yes, I milled the sides to have a Z-shaped overlap.

Nick

Now was this welding or brazing? Did the brass melt (and not just the rod). I ask, because I found some brass welding rods that are also for brazing steel.

Yes, the zinc is the problem. I just tried it with OA and both a reducing and oxidizing flame. But, well, I won't try it again with a stock brass rod. :-)

Nick

I've torch-brazed a few HEAVY brass pieces and had good success with it. This was a tank with a 1/4" brass bottom and .062 walls. I didn't have my TIG at the time, but will have to try it the next time such a job comes up. I have some low-temp brazing rod that melts at a low enough temp that melting the brass is not a problem.

Jon

For tight tolerances and production, I suspect the best way would be using furnace silver-brazing with a jig to keep things square and together. Usually a paste flux with ground braze filler or silver-braze filler preforms are used. There are books out there on the subject. If you could find someone that has a pottery kiln, you could probably prototype things using that. Or use soft solder if you don't need the strength. It's available as a paste in flux as well. You might be able to use a kitchen oven for that, depending on what solder alloy you get.

Stan

Yes, I have to agree with the experiences I had today. A jig is a must. But for the furnace, I have to step back. Would like to have, can't afford.

Nick

Don't braze in a pottery kiln. You'll destroy the refractory lining and you'll annoy the potter. Flux spills eat right through it and fumes aren't much better.

Have you ever tried Laser welding? I weld brass all the time with great success. I have to say that most of what I weld is less than 5mm but, I'm sure that it can be done. I use regular brass wire for the filler and it's very strong when done right.

Neill

Sorry that I asked, but some people can't distinguish between welding and brazing. You are _NOT_ one of them. :-)

That sounds very good!

I saw that with my quick-hack-test. :-)

Thank you for the very kind offer, but I fear I won't get that brand here in Kraut-land. But I'll stop by at my welding shop and ask for it. Now I know it exists and I know I can get acceptable results.

Nick

Wonder if a gas box would help - Argon maybe - Not only is the zinc vaporizing, but oxidizing also ? Might never beat it. Unless under a heavy layer of flux.

I was able to braze a bronze pipe to a 1/4" copper sheet the size of note book paper. That took a lot of heat.

I then did the same thing to a sheet of 16ga steel - and brazed a line - within heavy flux - then added the bronze pipe - and when the bronze rod attached to the pipe - it flowed into the puddle already on the steel. In a sense - I tinned the steel with a layer of bronze before trying to put the pipe on.

'tinning' is done in Tin-Lead soldering all of the time. It is useful in other metal applications as well.

Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder

Nick Müller wrote:

Not sure of your exact application, try jigging with castable refractory. Jewelers do it all the time. The soldering heat for hard or soft solder can be a transformer soldering machine. Google on American Beauty, one brand name. Can be homebuilt.

Not sure of your exact application, try jigging with castable refractory. Jewelers do it all the time. The soldering heat for hard or soft solder can be a transformer soldering machine. Google on American Beauty, one brand name. Can be homebuilt.