Plumbers' WD40?!

[Digger]

Hmmm . . . is there such a thing?

I'm attempting to undo an undersink trap that has stubbornly corroded itself together at the uppermost connection directly under the sink. Obviously I dont want to damage the sink-side section but no amount of brute force and ignorance with two pairs of plumbers 'pliers' is unscrewing the damn thing.

Do plumbers resort to some sort of chemical wonder to loosen of these problem connectors?

[jas xjr]

is it a plastic trap or a metal one ?

[B17NNS]

What are the materials involved?

[Digger]

The old and the new replacement trap appear to be a relatively strong metal of some description. The under sink threaded section appears to be brass (having scraped some of the finish away with the wrench).

[NiceCupOfTea]

Get some penetrating fluid in there?

[Digger]

Yeah I know hence the question as to the most suitable. As I am out of wd40 and off to the shops do I buy said product or something more appropriate!?

[Ferg]

Heat.

[NiceCupOfTea]

WD40 isn't penetrating fluid. Halfords will have some of the latter and be open on a Sunday.

[spikeyhead]

Either mess about with plusgas or similar penetrating fluid or out with the blowtorch.

Careful using both as the fluids are often flammable.

[B17NNS]

I' try a bit of heat.

[mcflurry]

If you're replacing it, does it matter if the old bits that you're going to bin get damaged?

[944fan]

Plusgas all the way.

[Digger]

mcflurry said:

If you're replacing it, does it matter if the old bits that you're going to bin get damaged?

Nope, could be a hacksaw job but in the meantime bought some Wickes penetrating fluid. Will apply a few times and later I'll pour a few litres of boiling water down the sink & see if it shifts.

Thanks all.

[Digger]

Plusgas is it is then, soon to be followed by a hacksaw no doubt!!

[g7jtk]

Cut it off and buy a new one

[Digger]

Eureka! Patience & time to allow the fluid to penetrate has sorted it.

[Dogwatch]

Great! Was going to suggest shock and unlock otherwise.