in Australia contact the Primus-Sievert distributor: Australia -
Primus Australia Pty Ltd - T +61 394 642466 - F +61 394 642404
Their equipment is Swedish made – used world wide. They have a broad
range of tip sizes for their pro line. Their equipment is not widely
available in the US either. In the US acetylene got a head start with
the prestolyte torch. Sievert is first class equipment.
I tried different flux. I definitely need hotter flame.
Don’t confuse heat temperature with heat quantity. A cup of boiling
water has more heat than a red-hot needle. You don’t need a hotter
flame, you need more heat.
A good example is trying to use a soldering iron designed for
printed circuit boards to solder the seam of a coper jug; it will
have no effect. Use a soldering iron designed for the job, and it
will work. Both reach the same temperature, but the bigger iron has
more heat. It’s not hotter, just bigger.
As I mentioned before; a propane flame is quite hot enough to solder
silver and/or gold. Your problem is that that the heat is escaping
before it’s had a chance to get the joint temperature high enough to
melt the solder. Use fire bricks to conserve the heat and, possibly,
a bigger flame.