TIG welding brass ?

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I've got some brass fittings for my water line that cracked when the temp went down below 0 and we forgot to empty the lines...Is it possible to run a quick pass over the cracked areas with TIG ?  I know brass is usually brazed but I don't have an O/A torch.I'm just scared that the heat conductivity of brass will cause it just to melt the whole piece instead of creating a weld pool.Use pure (green) tungsten on AC ?Suggestions?"A winner isn't someone who doesn't lose, a winner is someone who doesn't quit."
Reply:The whole piece won't melt or fall apart suddenly as pot metal can; so long as you can control the input power, the pool should be controllable.......but....Yellow brass for plumbing has very high Zinc levels which tends to vaporize and cause porosity. Maybe spit too. If you have good control, you might be able to use a low-fuming bronze or a silicon-bronze without overheating the base metal, and get a good bond. Do you intend to do this in place, and can you prepare the cracks, keep the water away, etc.?  Sounds like it might be easier to just replace components than try to fix lots of cracks. Any pictures? More details?AC is used for cleaning on Aluminum but isn't needed on brass or bronze. If you do TIG it, try DC (--).
Reply:[quote=Oldiron2;268659]The whole piece won't melt or fall apart suddenly as pot metal can; so long as you can control the input power, the pool should be controllable.......but....Yellow brass for plumbing has very high Zinc levels which tends to vaporize and cause porosity. Maybe spit too. If you have good control, you might be able to use a low-fuming bronze or a silicon-bronze without overheating the base metal, and get a good bond. [/quote[Actually I was planning on just doing a fusion weld (no filler) if possible.  Just run the molten parts of the two sides of the crack into the same puddle.Do you intend to do this in place, and can you prepare the cracks, keep the water away, etc.?  Sounds like it might be easier to just replace components than try to fix lots of cracks. Any pictures? More details?
Reply:get your hands on some silicon bronze filler, its tig brazing.  Ive done that on brass parts before and it worked fine.Have we all gone mad?
Reply:shots showing the 1 large crack, the other bent piece needs to be bent back down flush then welded (mini-fillet weld) along the inside of the ring so it's sealed again.  The first shot I'll obviously bend it down flush before welding.  This is just to show the crack as-is right now. Attached Images"A winner isn't someone who doesn't lose, a winner is someone who doesn't quit."
Reply:pS: I'm using a 1/8" th tungsten.Should I use green or red tungsten (they're the only 2 I have available)Straight DC- or should I put it on pulse ?Last edited by z0diac; 03-31-2009 at 12:29 PM."A winner isn't someone who doesn't lose, a winner is someone who doesn't quit."
Reply:Note: a plumbing line/fixture IS pressure rated/related.  If you just fused the edge of a crack, the rest of the crack is still there on the inside.  If you brazed the entire crack you have totally filled the crack.  If you full-penetration weld the crack, you have totally filled the crack.If you just fuse the surface of the crack, you still have left most of the crack there.  Replace the fitting.  It only costs a few dollars, most of the 'cost' is the labor to replace it.If you want to try and practice and experiment with the cracked fitting, by all means.    I've melted many things that way.    The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by MoonRiseIf you want to try and practice and experiment with the cracked fitting, by all means.    I've melted many things that way.
Reply:Yes you can weld or braze that brass fitting with TIG.  You can use pure copper as filler metal in a pinch; but I guarantee the weld will be mostly cosmetic; in other words I wouldn't count on it under pressure.  I've TIG welded similar, using a piece of 14 gauge solid wire conductor from a piece of romex I had lying around...I do know that he brass will fume like crazy as the zinc in the alloy burns off.  Keep your head out of the plume or you'll end up with zinc poisoning.Braze with silicon bronze is probably the best method of repair.  But then this definitely looks like a waste of time to repair unless you just can't get a new part....Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:keep a lowheat tig torch and try to braze it... good friggin luck thats a pretty big gap..
Reply:Silicon-Bronze goes on so easy, even I can tig weld with it! Or, is it actually brazing??  Whatever you call that, it goes on easy! City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:Originally Posted by weldbeadkeep a lowheat tig torch and try to braze it... good friggin luck thats a pretty big gap..