Designer Radiator Valve Installation

[DLaing]

Last night I installed the valves on to my trendy new Bisque designer radiator. I wrapped PTFE tape around the threads and tightened. After filling, there was some water seepage from the joint (not the threads - the other side of the nut).

After numerous further tightenings, it still leaked, so I dismantled, added further PTFE around the joint and some Boss White. It seems OK now but the question is: should I have used PTFE and Boss White, or is an alternative jointing compound (perhaps silicone based) a better idea?

I discovered the radiator has a leaking weld anyway, so I have the opportunity to do it right when the replacement arrives!

 

[Jasonb]

Are you using Bisques own valves, I've fitted several of theirs and use a small amount of boss white both where the not joins the valve and on the olive where the valve joins the nut.

Jason

 

[DLaing]

Yep! I used Boss White on the connection to the pipework with no problems. Initially I just used PTFE on the connection to the radiator.

I take it PTFE and Boss White is the way forward then?

Am I the unluckiest person in the world to have a Bisque radiator leak from a weld or have you heard of other instances?

 

[2scoops0406]

Did you wind the PTFE (Poly Tetra Fluoro Ethylene or teflon to you and me...... (bloody daft chemists)) anticlockwise.

 

[DLaing]

Nope, definitely clockwise

 

[2scoops0406]

I have heard, (I'm not a plumber) that you are supposed to wind it anticlockwise, this is to compensate for the fact that to tighten the joint you have to turn it clockwise, thus enhancing the seal.

 

[DLaing]

But my understanding was that as you tighten the nut clockwise, you want the tape to be pushed into the threads, rather than being unwound by them.

 

[ChrisR]

Clockwise!

 

[Jasonb]

Looking at the end that will go into the rad I would wind clockwise, as you wind the thread into the rad it winds the tape on tighter.

Jason

 

[2scoops0406]

Intersting, I did a little, and I mean a little research on the web, on all the sites I deemed reasonable, those that expressed an opinion were evenly split between applying PTFE tape anticlockwise and clockwise. Now there is no way I'm going to cast doubt on an experienced plumbers views, I merely found it interesting.

 

[ChrisR]

I wish someone would invent something better - with more give in it. You never know how much is going to be enough until you've done the joint up! I have used a bit of LS-X leak sealer (type of silicone) , to answer the original question!

 

[PEDANTICVINDICTIVEMAN]

Pathetic when a company cant send out a bloody radiator without a leak on the damn designer garbage welded joint

 

[ArtfulBodger]

I wish someone would invent something better - with more give in it. You never know how much is going to be enough until you've done the joint up! I have used a bit of LS-X leak sealer (type of silicone) , to answer the original question!

I always use one wrap now - the normal PTFE is a complete pain & I have never understood how you are supposed to prevent 4' of the stuff from twisting before you put it on.

I would also be very interested in knowing of a product as good as LS-X which you can actually use more than once - you know, put the cap on and then when you take it off again for the next job you can get the stuff to come out of the nozzle as opposed to the tube as LS-X invariably does.

 

[ChrisR]

They've redesigned the caps on LS-X. If you look in the outer end you see there's a thin ring of plastic which invariably breaks. WOuldn't be surprised if it's porous enough to air to let the tube set, which it starts as soon as you open it.
If you fill the outer end of the cap with a hot melt glue gun it lasts a lot longer. Ordinary Silicon, or even some LS-X, slows the setting down a bit.

Have used the one-wrap "gas" tape for water and found it very intolerant of any movement in the joint. I wish I knew why one is thick and one thin!