Thru hull elbow adjustments

[kcj]

Have 13yo Lagoon with a thru hull, ball valve and elbow... I know at least the valve is groco. Valve works fine. Boat is in water.

I am redoing the sanitation hoses, and it makes sense to rotate the elbow 90 to 120d to get a cleaner lead to the loop..

Will I be able to rotate the elbow relative to the valve? How dangerous is this procedure? Or Is it better to leave it as is?

Thanks in advance for your thoughts

[rbk]

Personally i would at least try it. If its that bad it should be dealt with either way. 13yo for a bronze fitting should be fine. Just have a bung and a plastic bag handy just in case. Worst cast you replace a rotten thru hull.

[a64pilot]

You’ll probably never get the valve off of the thru hull. But the elbow should be able to be rotated some, usually tightening is the best direction.

[David M]

What material is that? Is it galvanized steel? If so, remove it and replace with a non corrosive material. Silicon bronze or a non brittle plastic is best. Putting heat to it from a propane torch might help with the removal.

[gonesail]

whatever you do make sure you have a wrench on the valve itself .. to make sure when you are working the elbow you don't twist the thru hull and break the seal .. and go easy. you might want to install a new bronze elbow.

[deblen]

Seacock vs Thru hull
https://marinehowto.com/category/plumbing/

[TrentePieds]

Thank you for that wonderful pic, Deblen :-)

It illustrates absolutely perfectly a design/construction/application concept that many novices do not clue into just by seeing the conventional designations such as "NPT".

TP

[billknny]

If it is a proper straight thread seacock tailpiece, and it looks like it might be, the chances of turning it tighter to adjust the angle are pretty small. The rational behind using straight threads for this are that the threads SHOULD bottom out.

Tapered threads, used on household plumbing, don't bottom out, and can usually be torqued a bit tighter to adjust the angle of a fitting.

[rbk]

If all parts are in fact Groco (they do appear to be) there are a number of ways to achieve the shown setup properly with matching threads. Groco makes combination thru hulls with nps and npt threads. They also make a dual thread nps outside, npt inside and could be made with an nps nut (shown) an npt nipple to the npt valve. Also groco only makes bronze and stainless metal fittings. No galvanized or otherwise. Im still with the majority in that a proper base flange is ideal but don’t condemn the shown setup based on one picture.

[deblen]

Originally Posted by TrentePieds

Thank you for that wonderful pic, Deblen :-)

It illustrates absolutely perfectly a design/construction/application concept that many novices do not clue into just by seeing the conventional designations such as "NPT".

TP

I copied that picture from Maine Sail/Compass-so he is due the thanks.


It is the perfect picture to explain why a NPS or BSS (Straight Thread) should never be used as a thru hull without their mating Straight Thread SEACOCK or Groco Adapter.
Len

[deblen]

Originally Posted by deblen

Seacock vs Thru hull
https://marinehowto.com/category/plumbing/


Attachment 192170

https://www.sailfeed.com/2013/10/no-...-and-seacocks/

[HopCar]

Old style seacocks were better at handling this situation. They had male straight threads on the discharge side instead of tapered. You would use a gasketed tailpiece. This allowed you to turn the curved part in any direction and then tighten the nut. Groco still makes the tailpieces but they don’t make a seacocks hat can use them.
https://www.groco.net/products/fitti...-standard-flow

Sorry that doesn’t help but I’m old and tend to ramble on.

[kcj]

Thanks for the Many insights from all!

Sounds like the risks outweighs the gains...especially while afloat

[GordMay]

You might use a 90 degree Bronze Elbow Union, consisting of three parts: a nut, a female end, and a male end. A union (as opposed to a coupling) allows easy connection and disconnection, and alignment.