Flux Residue (Green) on Copper Pipes & Pushfit (Speedfit

27 Jul 2007
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United Kingdom

I used some speedfit the other day.

I had to make a connection to the existing copper pipework.

I cleaned with wire wool the green staining and other muck for a couple of inches at the end of the pipe where I pushed the Speedfit connector.

I've just realised the green staining would have likely been residual flux left behind from years ago when the original copper pipes were welded.

So I am now concerned that the speedfit connection will be compromised as I've been reading flux is a big no no.

Is years old flux staining/residue on a copper pipe likely to cause issues.

Is cleaning it off with wire wool sufficient?

Should I replace with compression or check the fitting in say a couple of months for any corrosion?
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Flux is acidic, so washing it with plain water and wiping with a cloth will neutralise it.

Of equal importance is the condition of the pipe. Make sure that the pipe isn't damaged or distorted, and check for indentations. Make sure that there isn't any solder on the pipe that could interfere with sealing or the grab ring.

I have seen push-fit fittings blow off where there was only very slight distortion or damage to the pipe. This affects the grab ring's ability to grip the pipe.

If in any doubt, use a compression fitting instead with the correct insert in the end of the plastic pipe.

Copper pips is good and straight.

I cleaned up with wire wool which mixed with water as I was doing it due to the pipe being low down and dripping a bit.

I then wiped with a damp cloth.

The fitting is in place as I type and is sound and watertight.

What concerns me is whether the flux having been on the copper and going green before I cleaned it off will still be acidic to the speedfit connection and is it likely to corrode over time and pop off one day out of the blue!!

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