Tig Welding Bronze

[SoCal Dave]

It's been some time since I last posted about my bronze hummingbird project.  I have a photo of the final version.  The beak and the wings were tig welded.  I had the welder set at 100 amps, and after running some test pieces, I found out that Bruce, and others were right.  Get in and out quickly.  After adding some rod, I was able to blend it to the body.  The difficult part was the wings were thin and the body thick.  It didn't take much for a previous weld to melt when heating the body up for the next weld.  Quick in and out still was key.  After talking to Dorothy Stiegler, who was very helpful and supportive, I used some 120 grit sandpaper, and Johnson paste wax to protect  it.

 

[DSW]

Very nice.

 

A lot of people forget what a great heat conductor copper based alloys and alum are. Best bet is to often hit them fast and hot so the rest of the material doesn't heat sink away the weld heat and heat up the whole project. Something that can be really critical if you are brazing vs true welding.

[SoCal Dave]

DSW - I did feel the tig was more of what you described, more of a brazing.  

[DSW]

Tig brazing is quite common with metals like brass where you have to watch that you don't overheat the material and boil out the zinc. The lower temp allows you to join the material without damage to the base metal.  Bronze can lend itself either to tig welding or brazing depending on the exact alloy.

 

Your comment about having a previous "weld" melt made me pretty sure that you were probably brazing. In an art application it probably doesn't matter much other than trying to get a good color match.