CS wrote:
I have some lengths of cooper bar - 1 inc x 1/2 inch x 5 inch - used
as interconnectors on 2v battery cells. I wish to tin them and can
either cart them off to an electroplater or tin with solder. Solder
wire worked fine on a test piece with a blow torch. My question is
which solder bar to go for - lead free or leaded?? My instinct is
leadfree - tin with some silver and possible copper - something like
Sn96/Ag4.

Unless you need to use lead free solder, I would use traditional
lead-tin solder. The general consensus seems to be that lead free solder
is less satisfactory and more difficult to work with.

Best wishes,

Chris