Repairing a Crossed Plastic Thread

[Ian Grantham]

I have almost completed fitting a toilet when unfortunately I crossed the plastic thread coming out of the cistern when trying to attach the metal water supply connector.

Is there any way that I can repair the plastic thread so that I can attach the supply again?

[stanleyman]

You won't be able to repair it but you can probably rethread it as you connect. This can happen because of difficult access. The best way is to remove the cistern so that the connector is accessable to make the connection while you can see the alignment properly. Don't forget the washer.

You should have a service valve in the line and this can be used to break the line and make the final connection easy. Once you have encouraged the threads to go in the right way and have tightened up, refit the cistern with the tap connector and a short piece of pipe already connected. It's a simply matter to then connect to the service valve.

[ploughman]

Had self same problem when fitting a Redring shower. Just kept trying to straighten the plastic thread by re screwing the metal compression nut several times. Eventually succeeded.Lubricant may help. You may have enough length on the plastic thread to cut a small section off and start again. Good luck!

[joko]

try plumbers tape - the unsticky white paper/plastic stuff

[snook]

joko means PTFE tape. It's only about 40p a roll, from B&Q, plumbers' merchant or any good DIY outlet.

[timcapper]

If there's enough thread exposed, try cutting off the damaged part - check to see if there's enough play in your water supply pipe first!

[xrayspecs]

Buy another one - forget rethreading or PTFE tape.

[ploughman]

Dont use PTFE tape!!! Using this is what causes the trouble with plastic plumbing fittings in the first place.