What's best for sealing and locking threads on skin fittings, seacocks & Hose tails?

[Albert Ross]

What's best for sealing and locking threads on skin fittings, seacocks & Hose tails?

I'm replacing all my skin fittings, seacocks etc.
I need something to stop the threaded joints leaking and untwisting.
Something to seal and to lock the joints.

What's best .. ?

PTFE tape (seals but doesnt lock) ?
Loctite (locks but does it seal) ?
Pipe jointing compound ?

What have you had success with ?

Thanks

 

[thalassa]

For fitting the valves on the skin fittings I've used Loctite 55 cord sealant. Much easier than PTFE tape. Still fine after a year.
http://www.youtube.com/watch?v=3o4uMq6yQiQ

 

[VicS]

I'm replacing all my skin fittings, seacocks etc.
I need something to stop the threaded joints leaking and untwisting.
Something to seal and to lock the joints.

What's best .. ?

PTFE tape (seals but doesnt lock) ?
Loctite (locks but does it seal) ?
Pipe jointing compound ?

What have you had success with ?

Thanks

For the threaded joint between say a ball valve and a skin fitting, which both have parallel threads, a back nut will enable you to lock the valve on the skin fitting firmly with the valve orientated for convenient operation.

almost any sealant suitable for use underwater will seal the joint.

 

[Albert Ross]

Thank you.

Loctite 55 cord sealant looks good for sealing.

I have back nuts for fixing the orientation of the valves.
There are however, other fittings which need to be sealed and correctly orientated but for which there is insufficient space for back nuts .. for example, angled hose tails that need to be sealed and fixed in particular position. These usually to have BSP taper threads.

Any more suggestions, please?

 

[vyv_cox]

I don't think I have ever heard of one of these fittings loosening by itself. Certainly none of mine have. I doubt very much that you need to be concerned about locking elbows and hose tails to the valves. I have always used Sikaflex 291 for virtually evey one of these jobs on board, although more recently I have been using PU40 which is half the price. I am also trying some of the hybrid sealants that seem to have plenty of successful users on these forums.

 

[PCUK]

Builders Sikaflex.

 

[KevinT1]

It depends if you are sealing the through hull fitting to the hull or the thread on the Bronze fittings

I asked Hallberg Rassy what to use to seal the threads - "would sikalflex or plumbers hemp be acceptable ?" and got this response "You must be joking, Sikaflex and ”plumbers hemp”. Serious?! The Yard is using Loctite 275, the best. If you need to dismantle something only use a heatgun, clean the area and reassemble"

Not cheap - but you can adust the angle and then it goes off in about 2 minutes.

 

[geem]

We use Geocell Works for this job and lots of others. £5 per tube

 

[BERT T]

I'm replacing all my skin fittings, seacocks etc.
I need something to stop the threaded joints leaking and untwisting.
Something to seal and to lock the joints.

What's best .. ?

PTFE tape (seals but doesnt lock) ?
Loctite (locks but does it seal) ?
Pipe jointing compound ?

What have you had success with ?

Thanks

CT1 will do both jobs, just make sure the surfaces are grease free before assembling.

 

[Keith-i]

Loctite 577. Easy to apply, can adjust the angle to suit and good strength; though weak enough to allow for the fitting to be undone if necessary.

 

[superheat6k]

Loctite 577. Easy to apply, can adjust the angle to suit and good strength; though weak enough to allow for the fitting to be undone if necessary.

+1 and only Loctite, not any cheap would be Loctite thread sealant. Will also re- seal weepy o rings, and gaskets.