Thread sealant for seacock ball valve?

[er9]

I read Mainesails article on replacing seacocks and thru hulls. He didn't say if or how he seals the threads between the Groco adaptor plate and the ball valve or from the top of the ball valve to the hose fitting.

in one of the picture there is a can of 'Megaloc' thread sealant and teflon tape. im assuming thats whats used or something similar? would you use teflon tape preferably or liquid pipe sealant? is one better than the other?

I dont think he would use the Sika 291 because it seems that would make it difficult to remove if necessary.

Thanks

[a64pilot]

I personally like the tape (less mess) but many like pipe dope.
I don’t think it matters, but we will hear different opinions I’m sure.

[sanibel sailor]

Straight or taper threads? Taper does not require sealant. Teflon tape reduces force needed to seat but does not “seal”

[er9]

Originally Posted by sanibel sailor

Straight or taper threads? Taper does not require sealant. Teflon tape reduces force needed to seat but does not “seal”

thanks the threads at those two points are NPT tapered. Groco valve and base.

[slug]

I use loctite thread sealant with Teflon on just about every plumbing joint

Different bond strength sealants are in the catalogue

[mikereed100]

Originally Posted by sanibel sailor

Straight or taper threads? Taper does not require sealant. Teflon tape reduces force needed to seat but does not “seal”

That has not been my experience. Whenever I have failed to use tape or pipe dope on tapered threads they leak, even with nylon fittings. When I disassemble and re-do with Teflon tape the leaks stop.

[er9]

thanks ordered both. will play around with them and see which one is easier to work with. doesnt seem like one is better than the other. McMaster had some very high temp/pressure tape that might be good for my fresh water circuit plumbing though.

[Coolerking]

RectorSeal T plus 2.. I build lots of seawater manifolds for our systems...this stuff works.

[Cheechako]

Originally Posted by mikereed100

That has not been my experience. Whenever I have failed to use tape or pipe dope on tapered threads they leak, even with nylon fittings. When I disassemble and re-do with Teflon tape the leaks stop.

Yeah, not my experience either, although... if you tighten pipe thread tight enough it will stop leaking. But man, I'm not going that far!

[Compass790]

Either or both will do. I've done a lot of threaded pipework & the best I've used for problem joints is Heldite & hemp but that is real messy. Virtually as good is pipe goop ( loctite hydraulic pipe sealant good but there are many others) followed by PTFE tape wrap then on top goop again.
Mostly though just thread tape is enough but use goop as well if you want to be 100% certain it wont leak at the threads.

[a64pilot]

As a kid I plumbed several houses with iron pipe, we cut and threaded our own lengths.
Never used any kind of sealant and it’s not needed with NPT threads.
Having said that I still use Teflon tape now it’s acts a a lubricant and makes it easier to tighten fittings, and I figure can’t hurt either, but it’s not necessary, not if the threads are correct and you tighten the fittings correctly.
NPT is of course an interference fit, tape or dope adds interference when there is none.

On edit there is essentially no pressure to speak of on a thru hull, it had better not leak or you have real problems

[mvweebles]

Why use an adapter plate with valve? I use the BV sea cock - straight thread beneath, NPT above to nipple. Rock solid valve and eliminates a fitting, and it's closer to the hull so stronger.

Personally, I like sikaflex on larger plumbing fittings. No problem removing.

https://www.groco.net/products/valve...lves/bv-series

[a64pilot]

The adapter allows replacement of the ball valve, without replacing the thru hull.
Plus it’s not a big deal to replace a ball valve in the water if needed if you have the adapter.

[mvweebles]

Originally Posted by a64pilot

The adapter allows replacement of the ball valve, without replacing the thru hull.
Plus it’s not a big deal to replace a ball valve in the water if needed if you have the adapter.

I'm a bit confused, but probably just semantics. To me, thru-hull is a somewhat generic term. A common configuration is a mushroom thru-hull with straight thread stem. On the inside is the valve - I typically use the term "thru hull" for the entire assembly.

The Groco adapter plate (which I assume is what is being discussed) appears to be an un-valved method to transition from straight thread to NPT to allow installation of a ball valve. The broad triangle base is clearly stronger than mounting a ball valve directly to the stem of the mushroom fitting, but my confusion comes in mounting the triangular base plate requires same work as mounting a proper seacock and cannot be done properly with boat in the water.

I must be missing something. I'm redoing thru hulls as we speak so interested in feedback. Though I am a fan of well-backed seacocks.

https://www.groco.net/products/fitti...flange-adaptor

[NYSail]

I used both a small amount of tape then coated with pipe dope..... forgot brand but not a single drip. I spoke with tech at Groco and he uses and recommends using both as well.

Greg