unless you need a large roll, get a radiator shop to sell you a few yards of
solder and bring a bottle for a pint of organic flux. I prefer 70/30, but
many types are available. The Eutectic (longer heat range between liquid and
re-solidified ) solder used for rads is much better than the crap for
plumbing sold at your local hardware store.
http://www.alchemycastings.com/lead-products/solder.htm
I used to build new replacement radiators for rare cars, and repair some.
New stuff is much easier.The metal has to be absolutely clean and bright for
the joint to hold and the solder to flow.
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty