Brazing with Tig

[John_S.]

Can you braze with TiG using those flux impregnated brazing rods, the ones with the flux in the little indentations ?

Yes, No, Why ?

 

[Paul.]

No, standard brazing rods designed for oxy fuel processes, contain zinc, as well as flux which will boil out and contaminate the tungsten and the joint, for tig brazing you need silicon bronze rods, and no flux

 

[John_S.]

Thanks,
Think I still have some of these from the racing motor cycle days doing frames.
I'll have a dig out and try, I presume DC ?

 

[Paul.]

DC, not to high with the amps, remember you're not trying to melt the parent material, just the filler. give the rods a wipe with some scotchbrite or similar if they've been around for a while, and make sure the joint is clean.

 

[Highpower]

.... for tig brazing you need silicon bronze rods, and no flux

What would be a typical application for tig brazing? Dissimilar metals? Cast iron?

 

[Shox Dr]

As Paul Said you need Sifbronze No8 Rods, gas rods will spit like a rabid dog

 

[Tigman]

Friend of mine has a go-cart , all the joints on the frame were brazed with Tig , very neat job , never tried it myself , always use gas for brazing cause I have rakes of rods fluxed and plain , maybe try it out just for the crack !

 

[GrahamGKD]

As Paul Said you need Sifbronze No8 Rods, gas rods will spit like a rabid dog

Someone told me I could use the normal (gas) rods for TIG so I tried them - you are not wrong - they spat and popped all over the place!

Weldequip supplied me with some Sifbronze No.8s - they work really well but they are expensive.

Graham.

 

[Wallace]

I bought some Sifbronze No8 last week to repair a broken cast iron part on my lathe, after some practice on scrap material I found using the pulse helped control the amount of heat and flow of the bronze. I also found the cast iron test pieces were harder to control in comparison to mild steel and thought I had the hang of it so went ahead and started on the casting. I thought wrong, more practice needed!

 

[Shox Dr]

It does take some getting used to, I think you will find you are putting far too much heat into the parent metal, causing the Rod the boil. I have only tried it on CFS tubing, and it took a few goes before I was happy with the joint. If I was using it for Cast I would be inclined to preheat the item, so the joint doesn't require as much heat input.

What I will say is, it doesn't seem to flow like brazing with gas, the No8 is far stickier, not wetting, much at all. But then that might be my lack of experience with the process.

It would be nice to see a video of it been used by someone with more experience

 

[hotrodder]

What I will say is, it doesn't seem to flow like brazing with gas, the No8 is far stickier, not wetting, much at all

Yeah, albronze (sif #32, C13) is supposed to have much better wetting characteristics but with TIG the heat source is so concentrated i can't see it even approaching the capillary action you get with oxy.

I've found the easiest way to use the brazing wires with TIG is to lay the wire in/on the joint rather than dipping. If the heat is right the wire will flow* if too cold/fast it'll ball up or shrivel back. Too hot/slow and the pool will get a dark,scummy skin. On sheet metal (i.e. not constantly changing angles) you can go like the clappers when you get used to it

*flow/wetting out closer to that of a weld than brazing with oxy