How much flux should be used when soldering a pipe?
Question:
Answers:
Enough so that when you use a flux brush and paint it on the fittings there is a uniform coating all over before you apply the heat. And that is not much - maybe a couple of blobs about the size of a green pea.
The flux should flow up the pipe. It is more an art than a science.
A thin layer of flux inside the fitting and on the pipe is all that is needed. Any excess will merely melt and run off.
Just use enough flux to coat the inside and outside of the surfaces.
Tough to describe.
Coat the 2 pipes with flux and don't worry about if you put too much on. The excess will get thin with heat and drip away.
It can make a mess of what's under it so be ready.
Solder is another story.
How much? Use a brush and apply a thin coat. Flux is used to help make the solder flow easier. The biggest thing is to make sure your joints are clean and shiny, free of any oils and dirt. Don't touch a clean joint even with your fingers. Make sure your heat source is "above" the joint you are soldering, as it is the heat that draws the solder into the joint itself.
Surprisingly, it takes very little.
When you apply it, a thin coat inside the fitting and on the fitting area of the pipe is all that is needed.
Johnson's if a very good brand by the way. So is Laco
NoKorode separates in the can and has caused problems for me on the job, so I stay away from it.
Flux prevents oxidation which hampers solder from attaching to the copper.
More Related Questions & Answers...