Thread sealant for sterntube assembly -recommendations, please.

Poignard

Poignard

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The traditional type of sterntube assembly consists of a bronze tube with a thread cut on each end for the inboard and outboard bearings to screw onto.

What type of pipethread sealant is best for sealing this thread?

Access to the male thread is very restricted so PTFE tape is no good.

I want something that can be taken apart in future, i.e. a sealant not an adhesive.
 
I used caulking cotton - just a thin thread and Boatlife caulking which is not an adhesive. No problem getting it undone again
 
If your not in a hurry (couple of days) I have the type recommended by manufacturer of my boat. The prop. shaft bronze sleeve is jointed in the middle with a bronze coupling, inside this is another cutless bearing.When you use the sealant dont put sealant on all the threads as it sets as you tighten and you wont be able to tighten fully.you only need 2 threads covered on the male bit(at the end of the thread,not start) and 2 threads on the inner part of the female bit.I used a cocktail stick for the female bit.It also wants to be as cold as possible. If you balls it up as I did first time,I put too much sealant on, You can undo it with a blow torch,but you might knacker the cutless! !
 
Laco manufacturs a PTFE paste which you can buy from most pipeline or plumbers merchants. It is a paste and not an adhesive. I use it regularly on high pressure screwed pipejoints and it works fine. Put plenty on both the male and female threads, the joint will disgard any residual paste.
 
Not sure that is necessary. The threads do not need locking if the housings are held in place with screws into the deadwood. This needs sealing anyway and a caulking is perfectly adequate and comes undone relatively easily.
 
I used Boatlife polysulphide when I did mine. Just a smear on the threads inside the outer bearing housing and on the end of the threads at the inner end of the tube. A good bead round the mating surfaces of the outer housing and clean off the excess before it sets.
 
[ QUOTE ]
I used Boatlife polysulphide when I did mine. Just a smear on the threads inside the outer bearing housing and on the end of the threads at the inner end of the tube. A good bead round the mating surfaces of the outer housing and clean off the excess before it sets.

[/ QUOTE ]

Second that ! Boatlife polysulphide. Designed for underwater and fairly easy to clean up the threads when taking apart again.
 
Thanks for all the helpful suggestions. /forums/images/graemlins/smile.gif

[Problem now is - which one to adopt? /forums/images/graemlins/confused.gif]
 
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