Using sealing compound ( LSX? ) instead of thread tape

Hi, all.
I've just installed another shower mixer ( an expensive Grohe one ), and as per usual, the connections to it are 1/2" BSP parallel.
The male BSP <-> compression adapters I obtained are a rather loose fit before we apply thread tape, and being a parallel ( as opposed to BSP-taper ) thread, they don't tighten up as you spin them on. They bottom out.
On goes the PTFE tape. In order to make even a vaguely 'tight' fit, I need to use what I consider a huge amount of PTFE tape. Something like 10 wraps or more. The threads are almost no longer visible beneath the tape! Then we tighten it up. Again, since it's a parallel thread, it doesn't get satisfyingly tighter as we do it up, it just continues at the same torque until it bottoms out. The more layers of PTFE, the higher the tightening torque.
This kind of works ( in as much as it usually remains watertight ), but is most un-satisfying. One of my connections then developed a 'weep', and I had to re-make it. Naturally, it was the most awkward one to get at. All in all, I'm fair scunnered of the "PTFE tape and BSP-Parallel threads" connection. So I'd like to look for an alternative, perhaps a jointing compound.
What I'd like to know is this:
What is the correct use of jointing compounds like LSX? Is it used *instead* of PTFE tape? How would it perform in the scenario I described, where a male BSP-P fitting is a fairly loose fit into the female? Is the viscosity enough to fill the helical leak path along the thread? Does it 'set' and provide mechanical strength as well as a seal? Or do I rely on bottoming out the fitting to loose the 'wobble', and let the LSX fill the helical leak path?
Or is it not suitable for this application?
--
Ron




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Why not try to use an old fashioned solution such as hemp and jointing compound. The threads of hemp easily stop any play. When they get damp they swell up and together with the sealing compound ensure the joint is water tight. I have always used this on coarser threads and when PTFE is not enough and have been very satisfied.
Good luck !
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On 2006-11-05 18:22:37 +0000, "Ron Lowe"

I've had this situation with taps such as Grohe and Hansgrohe, and for that matter, with large fittings on hot water cylinders and certain types of radiator tail and radiator.
I have used PTFE sealing liquid and it works effectively. Paint it on the male thread, leave it a short while to dry slightly and screw it in.
Two other alternatives:
- The age old hemp and Boss White (or green for potable) is very effective.
- Gas type PTFE tape. This is thicker than the mimsy plumbing stuff and doesn't have the same tendency to bunch up or be cut by the thread of the fitting.
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Ron Lowe wrote:

The trick with the ptfe is to apply a number of twists overlapping and increasing in thickness toward the rear of the fitting (you can twist the tape to make a narrower strand of it if needs be), so you have a cone shape to it. That way it gets tighter as you tighten.
Having said that, on large fittings (cylinder connections for example) I prefer hemp and boss white.
--
Cheers,

John.

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I found it very successful on a plastic thread connector to a cistern where the pipe was copper with a tap connector on the end and perhaps not perfectly lined up.
--
*Out of my mind. Back in five minutes.

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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I use this stuff (Pipe seal):
http://www.screwfix.com/app/sfd/cat/pro.jsp?cId 0136&ts796&id693
(But don't use it on immersion heater threads, you'll never get the bloody thing out again!)
Chris
Ron Lowe wrote:

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I've recently had to do the same job. I eventually gave up on PTFE and used LS-X and the ceiling hasn't come down yet!
I know you are probably not supposed to, but I just applied the LS-X over the top of the PTFE, as I couldn't be bothered to unwind it all! I didn't quite bottom it out.
What I did probably wasn't the official solution, but it did get my shower working. I also applied the same system to my leaking water softener connections, which had the same issue complicated by the fact that the male fitting was plastic.
Christian.
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Ron Lowe wrote:

Would this be any good? Loctite 55 Pipe Seal Cord 50m http://www.screwfix.com/app/sfd/cat/pro.jsp?cId 0136&ts714&idB142
--
Dave
The Medway Handyman
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