Flux

[coliholic]

Installing a complete CH system using a Potterton combi boiler and using copper pipe and having a jolly good time doing it. Great fun. Trying to keep joints to a minimum so bending the pipe to all sorts of weird shapes and it's all coming on well so far.

Soldered and tested a few joints and so far no leaks. The process I'm using is clean the pipe with wire wool, brush flux on the pipe and the joint and then heat till solder runs and add a bit more to solder "just to be sure".

But when I did my engineering apprenticeship many years ago, when Pontius was still a pilot, I recall that whilst you were heating the components, you brushed on additional flux whilst heating the join. Must admit I've done that with some of the joints and some I haven't and it doesn't seem to make a difference.

But what's the current correct practice? Add more flux or not? Maybe fluxes are better/different to the old fashioned Bakers flux we used in "the olden days".

Anyone know please?

 

[Whitespirit66]

A light even coat on the pipe, twisting the fitting a bit as you push it over the end of the pipe.

Some people dip the tip of the solder in the flux, but it's not nacessary. You can use the brush to remove any excess build up from around the fittind hole when the pipe has been inserted, but you don't need to be brushing more on.