actionoptics
Well-Known Member
What is the recommended method/material to seal the threads of the new stop cocks I am fitting. Is PTFE tape sufficient?
Sealing stop cock threads
- Thread starter actionoptics
- Start date
fluffc
Well-Known Member
It's what I use.. and the boat's not sunk yet /forums/images/graemlins/tongue.gif
Searush
Well-Known Member
PTFE tape is the modern stuff, old timers like me might use white lead if we can get it - but it does tend to harden with age.
ShipsWoofy
Well-Known Member
work fine for me too.
garvellachs
Well-Known Member
Using ptfe tape, how do you overcome the problem of tightening up the valve and it coming to rest in the wrong position for the handle to open and shut - in a tight space that is. I've found myself trying to vary the amount of tape to get it to tighten in the right final position but it all seems too crude? Any thoughts?
Blue5
Well-Known Member
I was reccomended a liquid sealant called "Heldite" obtainable from plumbers merchants and allegedly used in aircraft indusrty.
Does what it says on the tin and the boat aint sunk (yet)
Does what it says on the tin and the boat aint sunk (yet)
ShipsWoofy
Well-Known Member
If you find out please tell, I have two that are not quite where I would like them.
I guess you could saw off the top threads of the through-hull until it is in the correct orientation, but I will live with a 10° offset.
I guess you could saw off the top threads of the through-hull until it is in the correct orientation, but I will live with a 10° offset.
ShipsWoofy
Well-Known Member
I have a big tube of that in the shed, used is for gasket sealing in the past, no reason it should not work. It is quite nasty stuff and requires ventilation while applying, if it is the same strength of the aircraft stuff.
Blue5
Well-Known Member
To vercome orientation problem I used a backnut, offered it all up dry until I got the correct position and then removed the valve and painted the thread with sealant (Heldite)
FrankJB
Member
I posted this back in Novermber for for what it's worth...
"I had a bad experience with PTFE tape last season. I had fitted a new skin fitting and seacock the winter before using PTFE tape for the seacock joint. It worked fine for that season but after the following winter lay-up it began to seep on relaunching (costing me a vast sum of money to have it hoisted out again for 20 minute to fix it!).
When I dismantled it I discovered that the thread was such a good fit it had removed almost every trace of the PTFE tape!
I would use Hylomar or Hermatite with the benefit of hindsight. "
"I had a bad experience with PTFE tape last season. I had fitted a new skin fitting and seacock the winter before using PTFE tape for the seacock joint. It worked fine for that season but after the following winter lay-up it began to seep on relaunching (costing me a vast sum of money to have it hoisted out again for 20 minute to fix it!).
When I dismantled it I discovered that the thread was such a good fit it had removed almost every trace of the PTFE tape!
I would use Hylomar or Hermatite with the benefit of hindsight. "
abbott013
Well-Known Member
A boat yard recomended PTFE and sika flex on threads, the threads are not tapered so i used brass nut (like the ones on skin fittings) to lock the valve to the skin fitting
Searush
Well-Known Member
Apologies for minor thread hijack;
[ QUOTE ]
(cut) (costing me a vast sum of money to have it hoisted out again for 20 minute to fix it!).
(cut)
[/ QUOTE ]
I love the LM27 long keeler, but why did you haul her out rather than drying out against a quay? One tide would have seen you sorted and a long keeler would be comfortable enough if you got her to lean a bit with chain or water butts.
Not criticising, just trying to understand the problem better.
[ QUOTE ]
(cut) (costing me a vast sum of money to have it hoisted out again for 20 minute to fix it!).
(cut)
[/ QUOTE ]
I love the LM27 long keeler, but why did you haul her out rather than drying out against a quay? One tide would have seen you sorted and a long keeler would be comfortable enough if you got her to lean a bit with chain or water butts.
Not criticising, just trying to understand the problem better.
Sheff
Well-Known Member
[ QUOTE ]
Using ptfe tape, how do you overcome the problem of tightening up the valve and it coming to rest in the wrong position for the handle to open and shut - in a tight space that is. I've found myself trying to vary the amount of tape to get it to tighten in the right final position but it all seems too crude? Any thoughts?
[/ QUOTE ]
If it's stopped in the wrong position.............. use a bigger spanner /forums/images/graemlins/smile.gif
Using ptfe tape, how do you overcome the problem of tightening up the valve and it coming to rest in the wrong position for the handle to open and shut - in a tight space that is. I've found myself trying to vary the amount of tape to get it to tighten in the right final position but it all seems too crude? Any thoughts?
[/ QUOTE ]
If it's stopped in the wrong position.............. use a bigger spanner /forums/images/graemlins/smile.gif
Sheff
Well-Known Member
[ QUOTE ]
A boat yard recomended PTFE and sika flex on threads, the threads are not tapered so i used brass nut (like the ones on skin fittings) to lock the valve to the skin fitting
[/ QUOTE ]
PTFE should only be used on tapered thread. If a parallel thread then a mechanical seal is required........... doughty washer or similar.
A boat yard recomended PTFE and sika flex on threads, the threads are not tapered so i used brass nut (like the ones on skin fittings) to lock the valve to the skin fitting
[/ QUOTE ]
PTFE should only be used on tapered thread. If a parallel thread then a mechanical seal is required........... doughty washer or similar.
abbott013
Well-Known Member
If it's stopped in the wrong position.............. use a bigger spanner
not a good idea unless you hold the skin fitting, to stop it moving and breaking the hull seal.
not a good idea unless you hold the skin fitting, to stop it moving and breaking the hull seal.
Sheff
Well-Known Member
[ QUOTE ]
If it's stopped in the wrong position.............. use a bigger spanner
not a good idea unless you hold the skin fitting, to stop it moving and breaking the hull seal.
[/ QUOTE ]
Nope, definitely not, which is why the smiley made it a light-hearted post.
Seriously, if it's a metallic through hull fitting with enough exposed threads between hull lock-nut and the valve you're fitting you could use a toothed wrench (stilsons etc.) to oppose the force of a larger spanner.
If it's stopped in the wrong position.............. use a bigger spanner
not a good idea unless you hold the skin fitting, to stop it moving and breaking the hull seal.
[/ QUOTE ]
Nope, definitely not, which is why the smiley made it a light-hearted post.
Seriously, if it's a metallic through hull fitting with enough exposed threads between hull lock-nut and the valve you're fitting you could use a toothed wrench (stilsons etc.) to oppose the force of a larger spanner.
abbott013
Well-Known Member
Just one last thing, what is a doughty washer, can you post a link so i can see a mechanical thread seal.
FrankJB
Member
I think its Dowty as in Dowty Rotol. Here is a link Dowty Washer
FrankJB
Member
[ QUOTE ]
Apologies for minor thread hijack;
[ QUOTE ]
(cut) (costing me a vast sum of money to have it hoisted out again for 20 minute to fix it!).
(cut)
[/ QUOTE ]
I love the LM27 long keeler, but why did you haul her out rather than drying out against a quay? One tide would have seen you sorted and a long keeler would be comfortable enough if you got her to lean a bit with chain or water butts.
Not criticising, just trying to understand the problem better.
[/ QUOTE ]
Yes, I'm totally with you on that but there aren't many places you can dry out in Poole Harbour and nowhere at Ridge Wharf which was where I was at the time. /forums/images/graemlins/frown.gif
Apologies for minor thread hijack;
[ QUOTE ]
(cut) (costing me a vast sum of money to have it hoisted out again for 20 minute to fix it!).
(cut)
[/ QUOTE ]
I love the LM27 long keeler, but why did you haul her out rather than drying out against a quay? One tide would have seen you sorted and a long keeler would be comfortable enough if you got her to lean a bit with chain or water butts.
Not criticising, just trying to understand the problem better.
[/ QUOTE ]
Yes, I'm totally with you on that but there aren't many places you can dry out in Poole Harbour and nowhere at Ridge Wharf which was where I was at the time. /forums/images/graemlins/frown.gif
boatbuilder
Well-Known Member
Put the skinfitting in place with the backing nut loose. Screw ballvalve onto skinfitting with someone outside to stop skinfitting rotating.
Rotate ballvave and skinfitting so that you can operate the lever, put sealant onto flange and backnut, tighten up.
Jobs a goodun.
Rotate ballvave and skinfitting so that you can operate the lever, put sealant onto flange and backnut, tighten up.
Jobs a goodun.
