mjb920 wrote:
I am having a problem sweating a quarter turn shut-off valve for a
bathroom sink. It seems that since the valve is such a large chunk of
brass it takes a lot of heat to get it hot enough to melt the solder.
The valve gets damaged from the heat and then leaks. Since this is a
ball valve there is nothing I can take apart before I heat it. Thanks
for any advice you can give me. Jim


That is why I use compression fittings on shutoff valves.
Easy to install, years of service, and when they finally fail,
you can just loosen the nut and screw another valve onto it.

But, to your question. Get a small towel soaking wet, open
the ball valve and then wrap the part of the valve that is
away from the solder socket with the wet towel. Make sure you
use Mapp gas for soldering and apply heat to just the end of
the socket (where the tubing enters).

--
Robert Allison
Rimshot, Inc.
Georgetown, TX