White thru hull: can I install a seacock on this?

[hd002e]

Near the bottom of my bilge I have this white thru hull, feels like some kind of plastic material. Within the thru hull I unplugged this bung (see photos). Since this is under the battery box there is no space to install a proper bronze thru hull and seacock with a wide base flange etc.

With a calculated risk I would need to install a 90 degree elbow above the thru hull and a ball valve after that. My question would be: can I use the existing plastic thru hull with a bronze or stainless elbow + valve or should I change the thruhull to the same metal material as well.

I want to draw water from there to a galley foot pump for seawater wash.

Please consider I am in Turkey and don’t have access to the beautiful apollo and groco fixtures that I wish I had. There is very little bronze here but plenty of brass and stainless fixtures. Which of the two evils is better?

Thanks all!

[Kettlewell]

I'd use a Marelon seacock/ball valve and replace the fitting with a matching marelon through-hull there if you can have one shipped in. https://www.forespar.com/marelon-mar...plumbing.shtml

I wouldn't trust no-name bronze or stainless fittings. The existing nylon fitting is not very strong, and is designed for above-waterline use only, with no attached valve.

[Weatherbird]

I wouldn't use bronze or brass for the galley because they can contain arsenic and lead. I would use stainless or reinforced plastic.

[deblen]

Would that fitting have been for a transducer?? & you removed the dummy blank plug.
From pic,IMHO,threads look too fine for pipe thread and there is definitely not enough thread length to make a safe,strong mechanical joint.
IMHO-re-install the blank plug & drill somewhere else for a new SS 1/2"-3/4" thru hull/seacock.
Cheers/Len

[stormalong]

Originally Posted by deblen

Would that fitting have been for a transducer?? & you removed the dummy blank plug.
From pic,IMHO,threads look too fine for pipe thread and there is definitely not enough thread length to make a safe,strong mechanical joint.
IMHO-re-install the blank plug & drill somewhere else for a new SS 1/2"-3/4" thru hull/seacock.
Cheers/Len

A new location would be your best move. Also, that plug/through hull looks like it is from a speedometer sensor. If you are not going to use it fiberglass it. No need for extra holes in the boat.

[hd002e]

You know that’s a very good point! It did look awfully like a sensor plug.

It must be super old because the existing electronics dont have a transducer of this kind. I will renew the orings, grease that baby up and keep it plugged in for the time being. I may glass that in at some point in the future.

I already have a spare marelon thru hull + seacock I can use for the galley saltwater pick up and it would make me feel much better to use a thinner diameter (I think a 1/2 or 3/4) than this gigantic hole all the way in the bottom of the boat (requires disconnecting and removing two batteries to get to.

Originally Posted by deblen

Would that fitting have been for a transducer?? & you removed the dummy blank plug.
From pic,IMHO,threads look too fine for pipe thread and there is definitely not enough thread length to make a safe,strong mechanical joint.
IMHO-re-install the blank plug & drill somewhere else for a new SS 1/2"-3/4" thru hull/seacock.
Cheers/Len

[wholybee]

You don't ever want to use white plastic below the water line, and you don't ever want an elbow between the through-hull and the ball valve, even if bronze. And, you probably shouldn't have it near the battery box, both because of water near the batteries, and depending on how situation you don't want a battery to every fall and land on and break it.

If an elbow is your only option, I suggest a new location.

[hd002e]

Thank you! Very valid points! This strengthens my fears (in a good way)

Originally Posted by wholybee

You don't ever want to use white plastic below the water line, and you don't ever want an elbow between the through-hull and the ball valve, even if bronze. And, you probably shouldn't have it near the battery box, both because of water near the batteries, and depending on how situation you don't want a battery to every fall and land on and break it.

If an elbow is your only option, I suggest a new location.

[stormalong]

Originally Posted by wholybee

You don't ever want to use white plastic below the water line, and you don't ever want an elbow between the through-hull and the ball valve, even if bronze. And, you probably shouldn't have it near the battery box, both because of water near the batteries, and depending on how situation you don't want a battery to every fall and land on and break it.

If an elbow is your only option, I suggest a new location.

Marelon through hulls are white plastic.

[Fuss]

Take it out, it does not look good at all. At the very least , replace it with a trudesign fitting.
But to really convince you, when your boat is on the hard, take a 2 pound hammer and hit it hard.
It might just shatter like glass.

[Bowdrie]

Originally Posted by hd002e

Since this is under the battery box there is no space to install a proper bronze thru hull and seacock with a wide base flange etc. Thanks all!

To me, this is the operative sentence.
Others have already mentioned uses/materials, etc.
Next time you haul out get rid of that plastic whatever-it-is and do a repair job.
Locate a new thru hull/valve where it has proper space to service and easily operate.

[s/v Jedi]

Originally Posted by Bowdrie

To me, this is the operative sentence.
Others have already mentioned uses/materials, etc.
Next time you haul out get rid of that plastic whatever-it-is and do a repair job.
Locate a new thru hull/valve where it has proper space to service and easily operate.

THIS ^^^

[capt jgw]

Originally Posted by Fuss

Take it out, it does not look good at all. At the very least , replace it with a trudesign fitting.
But to really convince you, when your boat is on the hard, take a 2 pound hammer and hit it hard.
It might just shatter like glass.

I just replaced all the T-hulls on my boat. They were white plastic, and instead of fighting to unscrew them I just whacked them with a hammer and chisel from the outside. They all shattered into a thousand pieces. That convinced me that I wasn't just wasting time and money on the project.

[Tupaia]

Originally Posted by stormalong

Marelon through hulls are white plastic.

The external mushroom is white and you can't see this from inside the boat, the valve body is black.

[capt jgw]

You could easily remove the sensor through hull and use the hole for a proper seacock, but it's going to be way bigger than you'll need for a galley pump. You'd them have use adaptors to get the house down to the correct size for the pump. Not elegant but possible. Best bet IMO would be to put the dummy plug back in and drill a new hole.