Sealant for skin fittings, hose tails and ball valves

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RJJ

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Hi all

Just planning for the fitting of trudesign through hulls and ball valves. Two questions please.

I am minded to epoxy the through hulls...trudesign recommend epoxy as one of a number of options. Has anyone done this (as opposed to the usual 291 or similar route) and has experience to share?

Second, what is the recommended non-permanent sealant for the ball valve and hose tail threads? I would like the option to remove without too much fuss...if there is such a thing! Thanks
 
As much as there are uses for Sikaflex I certainly wouldn't recommend, the bedding of through hull fittings is fine by me. Done it for years, and never had a comeback.

Ball valves and hosetails.. a trick I've used is the taping of threads with PTF and then smear/fill the threads with Sikaflex. The PTF gives you a degree of positioning flexibility, and the Sikaflex locks the joint. The PTF tape acts as the bond breaker if you ever need to remove. Again, I've never had a problem using this method over many years..
 
Lucy52 said:
I did this recently, answers on the TruDesign website.

How to install and seal a TruDesign Skin Fitting into the hull ?

Tru Design

lower down the page "download information sheet" for instructions.

What sealant can I use on TruDesign Threads?

Answer
Thread sealing options:
- - 3M 5200
- 3M 5200FT (fast cure)
- Sikaflex 291i
- Loctite 5331
- Loctite 55 Pipe Sealing Chord
- PTFE Thread Tape

Hope that helps.
Click to expand...
Yep thanks, I have the instructions. But keen to know which of the above is best on a non-permanent basis.
 
Tru Design tested all the ones they listed as being ok. Touch wood, I chose the Locktite 55, so that I could set the handle in a convenient position without worrying about the through hull thread position. This would also help the hapless poster who had all his handles fitted by the yard all over the place, he could remove them and refit them in the desired orientation with Locktite 55. From a previous post I believe you can get a locking nut too.

LOCTITE® 55 Pipe Sealing Cord
A coated multi-filament cord designed as a faster method than Teflon tape to seal threaded fittings. The main
advantage is that a component, for example a Ball Valve, could be screwed down then screwed back a turn to suit
positioning whilst still maintaining a tight seal. This eliminates the need to remove the entire Ball Valve and apply more
tape as with traditional Teflon tape.

I think there is no "right" answer.
 
I have recently replaced my remaining five metal ball valves with Forespar Marelon, having repalced the first two two seasons ago. I bedded the mushroom thru hull after trimming to the correct length, with 291, which I left a full week to cure, but I was carful not to get sealant on the thread where the valve itselfs screws on. I did use the valve gently screwed on the locate and hold the skin fitting whilst the 291 cured.

After a week's cure period I then screwed the valve on finally and hand tight using Loctite 577 smothered on the threads of both the make and female. I do not expect any leaks, but the loctite wil mean the valve can be removed without disturbing the skin fittign mushroom.

I would be concerned that epoxy would leave no flexibility in the joint.
 
Thanks, so recommendations so far are loctite 55 or 577, or the combined tape+291 technique.

superheat6k said:
I would be concerned that epoxy would leave no flexibility in the joint
Click to expand...

The idea of epoxy is to add structural integrity to the fitting. Trudesign say as much in their blurb. When farting around with hose tails etc in future there is potential to apply quite some lateral, twisting and downward force, and I am tending to the view that I will be more comfortable with epoxy plus silica.

I am not sure why flexibility in the joint would be preferable? Thanks
 
[QUOTE="RJJ, post: 7062000, member: 36536"
... I am not sure why flexibility in the joint would be preferable? ...
[/QUOTE]
I prefer a decent sealant and associated flexibility in case a pipe gets trooden on or some heavy rests on it. That said I have been bedding skin fittings in sealant for ~ 35 years and never had one leak.
 
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