"Ecnerwal" wrote in message
...

snip---- Wrap a damp rag around the middle if you like, but mostly
apply heat to the fittings, not the middle, and don't overheat

Yep!

I not only plumbed our entire new house, but I built the control panels and
manifold assemblies for the hydronic heating system. I've (successfully)
soldered more than 100 valves with no problems. I strongly support the
small strip of cloth, wet, wrapped around the body of the valve, away from
the two ends, which must achieve molten solder temperatures in order to
assure a fully soldered joint.

I have used both silver bearing (3-1/2%) and non-leaded solders---made by
Harris. I highly recommend them over the others, especially Oatey, which I
found to fill and run poorly. Use Bridgit for common
plumbing-----Stay-Brite for heating systems.

Clean the bores of the valves well with a stainless brush, and the ends of
the pipe with strip abrasive. Flux sparingly, but totally. Use an acid
brush. Use water soluble flux for easy cleanup. When the solder has
solidified, wipe down both ends of the valve with a wet rag, which will cool
and clean the solder joints perfectly. Do not disturb the joints until the
solder has set.

Harold