Welding Tips and Tricks

If I use silicon bronze to tack up something can weld over it with my regular mig wire? Never tried but just thought I'd ask before I got some bad results.

jroark wrote:If I use silicon bronze to tack up something can weld over it with my regular mig wire? Never tried but just thought I'd ask before I got some bad results.

You can weld over it if you want to include it. That part of your weld would be compromised. Not recommended.

ok thanks. Out of curiosity why would it be compromised? Do the two metals not go together without porosity?

Silicon Bronze is not steel and is a brazing rod, not a filler metal. It will mix with steel but is not a match. On something non-critical it's not much of an issue but we strive to do things by the book here. Are you just wondering or do you have something tacked with SIl-Br you are going to weld?

sometimes sili bronze is used over welds in art for a astetic appearance.
craig

motox wrote:sometimes sili bronze is used over welds in art for a astetic appearance.
craig

Along these lines, it just depends what the part is going to be used for. Why posters leave these crucial details out in the post I have no idea.

jroark, the part gets compromised if it gets stressed enough. Silicon Bronze, as the brazing rod that it is, is no where near as strong as steel. So in a very simplistic way, if the member is stressed enough, the pocket of silicon bronze would be kinda like porosity. Ever seen FEA analysis of steel structures, where red indicates a build up of stress (psi)?




The silicon bronze will give (you can imagine it being the "red" area) wayyy before the rest of the steel builds up stress. Once it gives, it can rupture/tear/crack and take out the steel next to it by initiating a crack in other-wise much stronger steel. Once a crack starts....well you know what can happen...

The heat required to fusion weld steel in an area that has any type of bronze alloy in the immediate vicinity will result in copper dilution of the base metal.

The base material becomes riddled with cracks and porosity and is structurally scrap.

When you do a gas welding course, they hammer it into you not to overheat the base metal when using bronze for this reason.

To be honest I have a pound of silicon bronze and was going to use it to tack up tables I build and then weld over it. It's not critical but I think I'll just use some other filler. I appreciate the advise and good info. Might find a better use for the silicon bronze later