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?