Which tungsten? And ac or dc?

[paulmitchell1984]

Im fancying trying my hand at silicone bronze welding/brazing..I have the rods but unsure which tungsten and if to run AC or DC.
Its not for structural more decorative, and the joint will be welded and ground out so it sits flush prior to this pass anyway.
It will be on steel, so assume dc.
Cheers

 

[anto44]

Experiment with both dc and ac. @doubleboost has mentioned having good results using ac for tig brazing

 

[anto44]

When I tried using ac I found turning the frequency down very low and set the balance to a high ep setting along with a balled or very bluntly sharpened tungsten gave the best results.
The low frequency gives a broader less focused arc which helps avoid melting the parent metal.
For tungsten I used 2.4mm red