Fix incomplete solder

I have a copper manifold that I attempted to build. It was a series of tee's, 90 degree angles, and straight pieces soldered together. Since it was very important that the manifold be level, I decided to put flux on all the pieces, put it altogether, and then start soldering it. As such, I soldered one side of it (the bottom) and then flipped it over to do the top. Except I made a glaring mistake -- the flux melted and flowed away. So now there is no flux left to finish the top side of the piece. Any suggestions?

I keep my manifold dry fitted nice and snug so I can take it apart for cleaning. If you want it soldered though, you should be able to solder the whole circumference of the tube all at once instead of top and then bottom. Just take it back apart. The solder will melt with the torch. clean it up really good and get it shiny again. When you heat up a joint, keep the flame down the tube a little ways. Don't put the flame where there is flux. When you see the flux start melting good, then hit it with your solder. Keep the solder in contact with the tube until it runs all the way around. usuallly happens pretty quick.

Undoing things is not a very good option... there are over 40 joints, and I doubt i have the propane left for that. I'm hoping for a better option

As long as it stays together there should not be a problem.

It leaked to begin with... it still leaks a little, but not nearly as much as it did initially (before applying any solder).

stephelton said:

there are over 40 joints

Click to expand...

Holy cow! What are you making?

I'd sure try to redo those before I'd take it apart. If you wipe the joints and reapply solder when you reheat the joint it will draw the solder into the joint. As the existing solder begins to melt apply more solder to the joint. It won't be pretty but nothing short of starting over with new pieces will look good.

If this is a mash tun manifold why do you care if it leaks?

Agreed, mine is just dry fit so I can disassemble it but the original question was how to fix the incomplete solder joints.

Hang the fittings you want to solder over the edge of the table and put something on the other end of the manifold to weigh it down. Heat the fitting from the bottom and add solder to the joint, it will draw through joint all the way to the bottom. You can also heat the joint up and brush some flux around it if you want, the heat will draw the flux in.