Firstly, hello all.

Not sure which sub-forum I should have posted this in, so if it's in the wrong one could a kind passing mod please move it?

My query isn't strictly refridgerationy, but I fgured you guys would have a lot of experience of soldering/brazing copper...

I'm building from scratch a large passive heat exchanger/radiator - the problem I have is in trying to solder thin heat fins (0.005"/0.125mm) to round copper pipe (0.4mm or 0.6mm thick walled). If possible I'd prefer to use high silver content solder (better heat transfer than tin and all).

This is my first time soldering metalwork and not sure what I'll need to solder the fins to the pipes.

Trying to keep things as cheap as possible, so don't want to have to buy an expensive blow torch if I can help it.

Things are also tricky as the fins are going to be 1cm apart so soldering is going t be a bit hampered. I picked up a small butane pencil blow torch from ebay for a few quid - is this going to be of any use?

I understand the large surface area to volume of the heat fins is likely to make soldering tricky as the heat will be dissipated very quickly... Would using high silver solder be out of the question, and does a small butane blow torch have any hope of soldering high Ag solder?

Any help massively appreciated.

Cheers,

Tom