Which Filler Rods for Tig and Gas Brazing?

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Good Morning,I am sure this has been asked and answered many times but I have searched and still not clear if silicon bronze and aluminum bronze filler rods (unfluxed) can be used for brazing with a Tig or gas torch?  Are the same rods capable of being used by either process for brazing or are there Tig brazing rods and gas brazing rods?I appreciate any and all assistance, guidance comments etc..Thank you.Joe
Reply:I use silicon bronze tig brazing rods for brazing with O/A, but I heat them and then dip them in 20 Mule Team Borax first. (If the filler rod is hot, the borax will melt onto it.) Also put plenty of borax on the workpiece...the dirtier it is, the more borax you need. (With some kinds of cast iron, for example, the borax will float out a LOT of crud -- graphite, I suspect.) You can get borax at Walmart and elsewhere.I seem to get better results using O/A for heat rather than tig for silicon bronze brazing. Seems like you have more control over heat that way. You can also see what's going on better -- and can avoid melting a steel or cast iron substrate -- since you're not forced to wear a dark shield. Seems like when I try to tig braze, I sometimes end up melting the steel or cast iron, too, which you don't want to do. You want it orange bordering on yellow, but no hotter, and I find it easier to see that color when using a dark green brazing face-shield, rather than a welding shield. You can also get bronze (or maybe brass?) rods for gas brazing that come pre-coated with borax flux. But I seem to do just as well by using uncoated SiB rods and then dipping in borax.Others here prefer tig for heat for SiB brazing. YMMV.Last edited by Kelvin; 20 Hours Ago at 07:35 AM.
Reply:Kelvin,Thanks so much for taking the time to answer my questions, it is so very helpful to me.  If I may, can you use a gas torch to braze with aluminum bronze filler rod?  I guess it's obvious I am hoping to avoid having separate rods for each form of brazing.Again, my sincerest thanks and appreciation for your help, I truly appreciate it.Joe
Reply:Sorry, don't know much about aluminum bronze. I'm pretty sure Minnesota Dave (moderator here) uses it and likes it. Maybe he'll chime in.
Reply:

Originally Posted by Kelvin

Sorry, don't know much about aluminum bronze. I'm pretty sure Minnesota Dave (moderator here) uses it and likes it. Maybe he'll chime in.
Reply:I like brazing rod with flux.Dave

Originally Posted by jbacc

Good Morning,I am sure this has been asked and answered many times but I have searched and still not clear if silicon bronze and aluminum bronze filler rods (unfluxed) can be used for brazing with a Tig or gas torch?  Are the same rods capable of being used by either process for brazing or are there Tig brazing rods and gas brazing rods?I appreciate any and all assistance, guidance comments etc..Thank you.Joe
Reply:For gas brazing the only distinction i have called out is flux or bare unless silver brazing then I  specify percent.For TIG I spec silicon vs Aluminum.  I've never used aluminum bronze.I tried bronze gas rod with TIG.  It was sluggish and ugly.  I think folk use it for color matching when welding different material.I have never o/a welded with silicon bronze.  Perhaps i will try it today...Silicon bronze is hard and hard to machine away.
Reply:

Originally Posted by tapwelder

For gas brazing the only distinction i have called out is flux or bare unless silver brazing then I  specify percent.For TIG I spec silicon vs Aluminum.  I've never used aluminum bronze.I tried bronze gas rod with TIG.  It was sluggish and ugly.  I think folk use it for color matching when welding different material.I have never o/a welded with silicon bronze.  Perhaps i will try it today...Silicon bronze is hard and hard to machine away.
Reply:Bronze is bronze and not brass. So silicon bronze and alum bronze can be welded, and is why filler rods are sold as such. Silicon bronze definitely is better for tigging dissimilar metals though, whereas alum bronze  is expensive, sluggish, and should be relegated to alum bronze base metals.Bronze gas rods may not be formulated or deoxidized for tig use.Weld like a "WELDOR", not a wel-"DERR"

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Reply:Did not know there was rod formulated for tig welding.  When I was doing TIG welding it was Aluminum casting and cast iron. TIG was not mush use in steel Fab work.Mig and stick was a lot faster and torch for brazing (can do torch brazing in a T-shirt👕 )Dave

Originally Posted by shovelon

Bronze is bronze and not brass. So silicon bronze and alum bronze can be welded, and is why filler rods are sold as such. Silicon bronze definitely is better for tigging dissimilar metals though, whereas alum bronze  is expensive, sluggish, and should be relegated to alum bronze base metals.Bronze gas rods may not be formulated or deoxidized for tig use.