Liquid or Paste Flux

by David
(Texas)

What, if any, are the advantages of gel or paste flux over liquid flux? The paste flux I've found seems to be geared toward electronic applications. I work in copper foil and lead came and have been using the same liquid flux for came and foil since I started working with glass several years ago.

Would appreciate your thoughts.

Answer

I personally use a liquid flux for copper foil and a paste flux for lead came. The paste I use is Nokorode which is available in most hardware stores as well as from most stained glass suppliers.

I don't use paste on copper foil work. It's too hard to clean off the glass and it does splatter. You use a lot more on foil then on lead, thus a lot more splattering! The cleanup for foil is quite different from lead cleanup, and paste flux is difficult to remove with water. Glasflux is my flux of choice for copper foil.

I like paste flux for lead because it stays precisely where I want the solder to flow. It doesn't spread around like liquid flux does. I always get beautiful solder joints with it. It doesn't splatter on lead because you don't hold the iron on it as long as you do when soldering copper foil. For cleanup, I simply wipe it off before I start puttying. The putty and brushing with whiting process cleans off any paste flux that remains.