preparation is the key.

do all your machining and mechanical work first

clean copper that has been cleansed of all oil or surface tension debris is
critical to your end product

naptha removes nearly all hydrocarbon type surface contaminants

to etch and open the atom structure, i use plain old toilet cleaner with
acid content (Hydrochloric) , even the smelly stuff works.

complete rinse in clear pure water until bright and shiny

then immediately into the solder bath or pot if you can afford it.

blowtorch heat will only cause instant creation of copper oxides, thus
causing troubel, that why we use solder pots

flux is cheap, use it freely

60/40 solderworks fine, lead free worksfine, lead alone will oxidize
eventually

use ventilation to draw fumes AWAY from the operators/personell supply
masks if needed.

"CS" wrote in message
...
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.

TVMIA