I know there have been a bunch of threads about using budget torches for frame building, etc. What I have is a Columbus Minimax frame which is mostly welded together. It's got a cracked seatstay joint to the seat tube(probably due to a lack of brazing done there). I would like to have a go at fixing that, and while I'm at it, built up some fillets over the welds for aesthetic reasons.

I have one of these torches around: Hot Devil MAP Pro Trade Torch Kit - 2 Pack - Supercheap Auto

What sort of filler should I be getting(something available in Australia)? From what I've read, 56% Silver looks to be the go. But since what I am trying to do is mainly non structural, is there any alternative(eg the solder used for copper piping, etc?).

And is there anything I should know?

I've got a lot of experience in electronics soldering, but very little in using a torch. Fillet brazing will be an interesting experience, but I am fine with filing and sanding away until I have a nice and smooth fillet.