undoing a plastic ubend under a basin

[newlyretired]

Is there a tool for this? It's pretty tight and I can't move it - and last time I took it off I couldn't tighten it enough to stop it leaking!

newlyretired

[AsleepInYorkshire]

I use a dry towel and an expanding wrench.

If you can't get a water tight grip then replace with new as it's probably the washer that's turned brittles or if you really want to spend as little as possible use some PTFE tape (but be prepared to test your patience)

Wickes do a range of cheap plumbing bits

AiYn'U

[bungeejumper]

I have an absolutely huge footprint wrench that my old dad used to have - the kind that can be adjusted to a wide range of gripping widths by moving a bolt. (Like this, only bigger. https://www.toolstop.co.uk/footprint-69 ... -wrench-7/) . But if you have to use that much force, there's a good chance that you'll nadger the big nut if it's only made of plastic. A strap wrench like this is kinder (https://www.amazon.co.uk/Silverline-598 ... 000O51BWW/), and it opens screw top jars as an encore.

Traditional tricks include dribbling a bit of olive oil down through the offending nut, and then using heat differential to shrink/expand the joint. Try putting a kettle of boiling water down the sink, followed by a jug of ice-cold water. If heat differential worked on the swinging arm bushes of a Triumph motorcycle, it ought to work on a plastic U-bend.

Agree with the last poster, though, that if it's that stiff, you might need to replace it. You can always cut the nut away with a mini hacksaw, followed by a judiciously twisted screwdriver. But try everything else first.

BJ

[bungeejumper]

Afterthought. I reckon AiY is probably onto it with the suggestion that the washer has gone brittle. (Or, as I've sometimes seen, it went in all skew-whiff to start with and is now crawling up the screw thread somewhere, far out of sight.)

If that's the case, a new washer ought to sort the problem, assuming that you can save the U-bend and the nuts. Ahem, I'm assuming that the washer is in the right way round, with the taper facing the right way? It wouldn't be the first time that that had happened.

BJ

[jfgw]

I second the hot water idea. Just running the hot tap may loosen it enough. I have never tried following it with cold water though. Hot water also helps when tightening up afterwards. I think it is more to do with softening the plastic than thermal expansion. Thermal expansion on a 1 1/4" trap nut will be insignificant compared to the flexibility of the plastic.

Tapping the nut around with an old screwdriver and a hammer might work.

Toolstation stock replacement trap washers and seals.

If you buy a new trap, pay the extra for a McAlpine one (assuming it will fit). Some of the ones from sheds are absolute garbage.

Julian F. G. W.

[bungeejumper]

If you buy a new trap, pay the extra for a McAlpine one (assuming it will fit). Some of the ones from sheds are absolute garbage.

Yip! B&Q's are particularly nasty, and the old Homebase ones were worse. McAlpines are the only ones I buy these days.

When we restored Bungee Towers, all those years ago, I found myself installing seven washbasins, three mostly double sinks, Toulouse and a bath, all in one go, and I still bear the scars from some of the crap fittings that were supplied with the hardware. A lot of it wasn't fit for purpose and had to be chucked immediately. So I still have a large box of unused waste pipe clobber, whose main function is to keep me supplied with washers, big plastic nuts and assorted other handy bits.

My biggest bugbear was that the supposedly one-and-a-quarter pipes could be practically any size - each manufacturer seemed to have its own pipe size standards, so as to force you to replace everything with a complete matching set of whatever you were trying to fix. (Gutter manufacturers are still doing it today. )

You can buy an assorted set of washers (fibre and neoprene/rubber) from a DIY store without too much fear of making a mistake. But wouldn't it be nice if they made bottle traps with the same sized sealing rings? I don't think I've ever dismantled one without finding that the seal has ruptured, which generally means getting a complete new trap because you won't see another seal in the shops.

Unless somebody knows different?

BJ

[GoSeigen]

Is there a tool for this? It's pretty tight and I can't move it - and last time I took it off I couldn't tighten it enough to stop it leaking!

newlyretired

Stupid question but if it is upside down are you turning it the right way?!

First thing I'd try is to apply a snugly fitting tool (e.g. pipe wrench) and whack it with a hammer to start it moving. If there's enough space, lengthen the tool handle with a metal pipe: a 4-5ft long handle works wonders...

GS

[bungeejumper]

First thing I'd try is to apply a snugly fitting tool (e.g. pipe wrench) and whack it with a hammer to start it moving. If there's enough space, lengthen the tool handle with a metal pipe: a 4-5ft long handle works wonders...

LOL, on a plastic nut? Well, you've brightened my morning. Right now, I think we can do with all the diversions we can get.

As a general rule, I find that brass nuts and screw threads respond to sudden shocks, because they may have become chemically fused into position, but poly plastic prefers a softly-softly approach, building the torque slowly until it shifts a bit. Would definitely start in with a strap wrench on this one. Still, each to his own!

BJ

[Dod101]

I have a sink bend which needs to be removed and cleaned out but I cannot move so I will revert to what I usually do in these circumstances and leave it to a plumber the next time I have one in.

Dod

[newlyretired]

Thanks for the suggestions - in the end I got the chap who originally installed the basin to come and sort it out

newlyretired

[stewamax]

If you buy a new trap, pay the extra for a McAlpine one (assuming it will fit)

Another vote for McAlpine!