I have followed this line of e-mails for a while and just felt the
need to add my two cents.
I currently live in Madison WI. where I have taken some classes at
the U of WI… The instructor of the metals course is Fred Fenster
and he is the main reason I went back to school since he is near
retirement. In the classes he teaches we would routinely solder very
large pieces of copper for rais ing ,sinking , sculpture, etc… the
way we were taught is to first use a lot of flux to prevent the
coppe r from oxidizing. Prips flux is great for copper and silver but
remember to cover the entire piece, inside and out, not just the
joint. Second the torch has to be large enough to bring the piece up
to solderin g temp before the copper can oxidize. The classroom has
several large gas and compressed air annealing touches that are great
for this as the flame
can be adjusted to be slightly reducing and about 1 - 1 1/2 feet
long. Third, have your piece on a rotating annealing pan so you can
turn it for even heating. Forth, resist the temptation to hold the
flame on the joint as this will burn off your flux, oxidize the
joint and the solder, the heat will only be carried to the rest of
the piece so the joint can’t heat to soldering temp, and it is easier
for you to melt a hole in your seam. this does take up a lot of space
and needs some major venting. so if you know someone who welds they
might be able to help you set up a temporary work area in a garage or
outside. You might also try contacting Fred Fenster at the
University of WI. Madison for advise and his schedule of where he is
teaching during the summer.
as a last thought I want to let you know where I had problems. I
have made jewelry for years and have mostly used the Smith Little
Touch. I had a very hard time with the size flame needed for big
items like hollow ware.
big job 3D big flame I tended to use to small a flame and gave my
self more work then I needed to.
Well that is more then two cents but I hope it helps you. gook luck,
Jerry Honorably, Gerald A. Livings