Sealing the threads on Trudesign seacock

[Mister E]

I have read a lot of stuff about sealing the through Hull but have not found any information about sealing the threads.
Do you just do them up really tight?

 

[PaulRainbow]

I have read a lot of stuff about sealing the through Hull but have not found any information about sealing the threads.
Do you just do them up really tight?

Tru Design

TruDesign recommends the following sealants:


Adhesive Thread Sealants:
- Sikaflex 291i
- Sikaflex 591
- 3M 5200
- 3M 5200FC (fast cure)
- Bostik 920


Normal Sealants:
- Loctite 5331
- Loctite 55 Pipe Sealing Cord
- 3M 4200
- PTFE (Teflon) Thread Tape

I have used OB1 on my Marelon seacocks, they might be difficult/impossible to unscrew, but i'm of the mind that if one needs to be unscrewed it's knackered anyway and i'm likely to be ash.

 

[lektran]

I've used 291 on upwards of 20 trudesign connections on my boat and only one leaked afterwards. I fully coat the male end and very lightly coat the female end (you get squeeze out inside the pipe if there's too much on the female end).

You shouldn't need to firmly tighten any of the fittings except for the thru hull nut

 

[thalassa]

Did two Trudesign valves with Loctite 55 sealing cord seven years ago. They are still fine.

 

[Boathook]

I used ptfe tape and a back nut so that i could align the handle.

 

[Gixer]

Did two Trudesign valves with Loctite 55 sealing cord seven years ago. They are still fine.

Just bought some 55 after the PTFE failed to seal a joint on my cold water system. Doing the job tomorrow, any tips? Does look pretty straight forward TBH.

 

[sailorbenji]

I used ptfe tape and a back nut so that i could align the handle.

Where did you find the back nuts?

 

[Moodysailor]

I'm using CT1 on mine, for the same reason as @PaulRainbow in post #2. I personally won't use PTFE or non-setting sealant as I don't want the possibility of the fitting moving.

Not related to the OP, but as advice, Loctite 577 is excellent for metal fittings.

 

[michael_w]

Loctite 55 is the dog's danglies of thread sealant.

 

[jwilson]

I've used OB1 and CT1 on both bronze and a Trudesign seacocks. Lets you align the handle as needed without a backnut. I did once need to change an engine inlet bronze seacock whilst afloat that had been fitted years ago with CT1/OB1. A bit of gentle heat and non gentle force and it unscrewed from the skin fitting. Put a new one on with more CT1 with water pouring in. That was about 5 years ago, no problems since.

 

[Boathook]

Where did you find the back nuts?

Originally from tek tanks. But having just looked they dont list them.

I suspect that a brass one from a plumbers merchants will do the job with a good life unless the bilge area constantly has salt water in it.

 

[thalassa]

Just bought some 55 after the PTFE failed to seal a joint on my cold water system. Doing the job tomorrow, any tips? Does look pretty straight forward TBH.

No tips, apart of checking a few YouTube videos out. It is not about feeding the thread into the thread channels. But to build up the thread around the fitting. You should have sufficient wire thread on to need some force to spinning the valve on, while still able to adjust the position with some effort.

 

[Gixer]

No tips, apart of checking a few YouTube videos out. It is not about feeding the thread into the thread channels. But to build up the thread around the fitting. You should have sufficient wire thread on to need some force to spinning the valve on, while still able to adjust the position with some effort.

Worked perfectly

 

[Graham376]

Plumbers merchants will have a few thread sealants to choose from, I use Fernox Water Hawk.