On Tue, 7 Feb 2012 14:41:58 +0000 (UTC), Doug Miller
wrote:

teabird wrote in news:b0ed7e7e-d0ed-4988-9825-
:

Hello,

I have some 1/2 inch type M copper pipe and 4 90* elbows that I'm
sweating together for practice. I've cut some 8 inch pieces and
yesterday was able to solder one end of each ell to 2 tubes. It took
a few extra tries but I was able to draw the solder into the joint
pretty well. There was alot of smoke created, white and brown. I'm
using yellow canister (Map gas?), cleaning the joints with emery
cloth, flux and using lead free solder.

Are you also using a MAPP torch? You won't get a proper flame if you try to use a bottle of MAPP
gas with a propane torch.

Today I can't seem to get the solder to draw in. I've prepared the
joints as before and am attempting to create a square with the tubes
so this time the ell is connected to 2x 8 inch pieces. I also notice
that even though the solder is eventually melting it is not drawing in
the joint, and when it hardens it has a yellow color to it.

Where are you applying the heat? A common mistake is to heat the joint between the pipe and the
fitting. Always heat the fitting only: the pipe will get plenty hot enough anyway.


You always heat the biggest heat sink first - which in this case is
the PIPE. The fitting is smaller and thinner and heats faster. I
always heat the pipe where the fitting ends, then move the torch to
the fitting just as I touch the solder to the joint.
Also, make sure to clean and flux both the fitting and the pipe.