For Stuart LeVine
Teresa, pass this along. First off my conversion of the 1.25 mm
thickness equals .049 in. or about the same as 32 oz. 32 oz is .043
in. or most people would say some thick stuff.
When I work with this thickness of copper using a oxy/acetylene
torch I use a #5 tip. The hole in the tip is about .7 mm or the forth
to third largest tip cleaner file of a standard tip cleaner. Of
course I am either brazing or using phos copper rod. It takes only
part of a second to get the copper hot enough, which would be a
medium red glow for the phos copper. You have to be quick with this
size of tip or you could over heat the copper and burn a hole. But
you want to make sure it is plenty hot enough for the rod to flow.
When using a oxy/proprane torch the temperature of the flame is not
as hot as an oxy/acetylene torch. Also I find it hard to braze with
propane. Just not enough concentration of heat at the location to
braze because of the tip designs. Therefore you are heating the whole
piece up not just at the location to weld. I would suggest if you
desire to use that thickness of copper use oxy/acty torch or like you
said you will be there all day trying to weld. Also the copper might
be building up scale or oxidation on the surface that will effect the
heat to penetrate. Make sure it is clean.