Tig Welding Brass

John Chamorro · Sat Oct 29, 2016 9:40 am

I got a piece of scrap brass from an old sailboat and figured I would give it a shot at TIG with both a low sulfur brass and copper Romex wire as filler. I have had brass/bronze wear parts before that needed building up so why not experiment? The material was 2"x1/8" and I cut it into about 8" lengths. I sanded the impurities off on all sides then buffed it shiny with RoLock discs. I beveled 1 edge on 2 pieces and set them up for a butt weld. Turned the heat up to around 200 amps with 3/32 ceriated. As I start to light it up and increase the heat it starts to puddle and then turns to a volcano of white impurities. I stayed with it and started to feed the filler. Holy crap what a mess but the welds looked good. After wire brushing off the residue and sweeping it away, I was satisfied with the results. I did butt welds and then took another piece and did a 90* to that. I started fooling with procedures looking for a smoother weld. I would describe the weld profile a violent, not the stack of dimes but more a stack of tree rings cut with a chain saw. My final experiment was to manually pulse at full stab 200 amps and shove as much filler as possible before it all fell out. A 3' stick of 3/32 filler gained about 3 " of weld. There was no difference that I could see with using Romex wire or the low sulphur brass rod. I did some cross cut to look at the welds and I would be satisfied should it actually have been required to join 2 pieces rather than a build up. I'll try and post a few pix later if anyone is interested.

Poland308 · Sat Oct 29, 2016 10:00 am

I'm interested in seeing those pics. I recently used some silicon braze rod to build up some worn spots on a grinder pump impeller. The pump motor died and the customer put in a new pump so I got the old one and did it just as a test. I just did surface build up.

RamboBaby · Sat Oct 29, 2016 10:51 am

The white plumes that you saw boiling out was the zinc in the brass. Not recommended for welding. Need to solder or braze it. Not sure what to solder it with but google is your friend.

exnailpounder · Sat Oct 29, 2016 11:49 am

RamboBaby wrote:The white plumes that you saw boiling out was the zinc in the brass. Not recommended for welding. Need to solder or braze it. Not sure what to solder it with but google is your friend.

x2...I silbrazed what I thought was a stainless nut one time. It turned out it was a SS coated brass nut. The SS burned off and the brass turned into a white powder fireworks display. Live and learn and damn those frigging Chinese nuts and bolts!

RamboBaby · Sat Oct 29, 2016 12:23 pm

I know that brass is full of zinc because my buddy is a machinist. I found out what welding zinc looks like because my buddy asked me to weld some chrome plated rings onto rebar to be used as tent stakes. The crap kept exploding and smoking white. I told him this chrome has something funny in it. He said it's not chrome, it's galvanised. Never saw galvanized before that looked like polished nickel.

Sat Oct 29, 2016 6:05 pm

RamboBaby wrote:The white plumes that you saw boiling out was the zinc in the brass. Not recommended for welding. Need to solder or braze it. Not sure what to solder it with but google is your friend.

I'm a fan of silver brazing. I do this occasionally to seal red brass and bronze valves to stainless pipe, usually NPT connections. I torch-braze them, as the wetting into the threads is much deeper than TIG-brazing, but I appreciate when I have to disassemble a TIG-brazed joint for the same reason.

Steve S