It is part “set up” and part torch size. When you want to solder one
piece on another you can set up on screening. This allows you to
heat from the bottom and then the top. I always put the most massive
piece on the bottom and heat from the bottom until I can see a dull
red color. Then move the heat to the top and heat there until you
see the solder flow. The trick is to recognize when you have heated
enough from the bottom. If silver is on the bottom, it will change
colors. It will change to a golden color, then grey, then the dull
red you are looking for. Don’t get to light or bright red, or you
may have the dreaded fire scale. I set a stainless steel screen
between 2 fire bricks. The is set up very close to the edge of the
bench.
The torch could be bigger. I have a natural gas/oxy set up. I have
seen people get great results with map gas that they get at the
hardware or builders supply. If you can afford a larger torch go for
it. The larger torch will help with things like casting in the
future. Steve Ramsdell