Thru-hull fittings at transom - 28TE

[Nancy]

We're replacing the thru-hull fittings on the transom. They all connect to drains in the cockpit. There are six of them:

• Two 2" black ones with flapper covers connect to the drains at the aft corners of the cockpit

• Four 1" I.D. white ones connect to the various cockpit sole compartments and lazarettes

Why do the black ones have flappers and the white ones don't? They all serve as drain fittings, all are connected to hoses inside the boat, and all of the drains are at approximately the same elevation inside the boat.

The white ones are Forespar Marelon and are easily sourced. Any idea what the black ones are and where I can find them? Can I use Marelon fittings instead? Any reason not to use Marelon?

transom-1-05.16.17-1600.jpg

thru-hull transon1-11.24.17-1200.JPG

thru-hull transon2-11.24.17-1600.JPG

[Sisu22]

I always thought that the flappers keep blue water from sloshing back into the cockpit through the large corner drains. But you are right that the other scupper drains are about at the same height so in theory water could come back up through those ones as well. Maybe just to a lesser degree and the scuppers have a longer way to go and some angles to slow down the flow. Not sure on the sourcing but if they look relatively functional maybe they can be re-used?

[Nancy]

maybe they can be re-used?

They broke when they came off the boat. The flange is molded to the threaded portion of the fitting, and the door hinge is molded to the flange.

[Sisu22]

Nancy - maybe these would fit the bill?

Attwood Corporation 3876-3 Scupper Valve
by Attwood Marine Products
Link: http://a.co/jjKDRsS

[amber jj]

On our 31 the 2 rear scuppers in back corners of the cockpit have the flaps to stop the back wash which if were not there could let a considerable amount of water in from a wave or when backing down.The other drains are for the hatches and those drains are connected to the through hulls by hoses with a check valve before the through hull fitting.

[Pitou]

A good candidate from Marine East:

https://www.marineeast.com/a_sch/sch_de ... &pid=09_03

[Nancy]

Thanks, Kevin! Somehow I overlooked those when I checked Marine East. They might be the ticket although I'd be happier with Marelon.

Amber, if we go with a fitting with no cover, we'll use a flapper such as the Attwood. Thank you.

[trevorpresler]

Hello! Thanks for the submission! Your post is quite interesting, and I am happy to be supplied with the full description of the process!

[Nancy]

P.S. I believe the MarineEast fittings are the same as the originals.

[Dr Luke]

Then there's always the Perko chromed bronze version...
https://www.westmarine.com/buy/perko--2 ... ecordNum=2

[Norseman]

Getting tired of standing water in the aft corner scupper wells: It goes green, nasty and never really evaporates as fresh rainwater keeps it full.
Has anybody filled in the bottom with epoxy to the level or slightly above the bottom of the through hull?
Should be a simple job with an instant reward and the only negative would the difficulty of removing and replacing the mushroom thru hull sometime in the future, if ever.
Am I missing something...?

AD5CAFCB-B17F-4327-9408-8A4E3A0552A1.jpeg

[Nancy]

If you fill those wells as described, won't water be blocked from draining into that well from the narrow channel that runs the length of the cockpit?

[Norseman]

If you fill those wells as described, won't water be blocked from draining into that well from the narrow channel that runs the length of the cockpit?

Nah, the narrow channel is a inch higher than the floor of the scupper well.
I am curious as to the function of the well, must be a reason they designed it that way, which is why I hesitate to fill it with epoxy.
Perhaps try with starboard first.

[Nancy]

Nah, the narrow channel is a inch higher than the floor of the scupper well.

Ah, the advantage to being able to walk onto your boat at a moment's notice vs. driving to the yard, climbing over snowbanks, setting up a ladder, finding a tall person to unzip the zipper door in the shrinkwrap, etc., etc. Nah, not happening.

Good idea to try first with something removable. I wouldn't want to epoxy over the thru-hull fitting.

[Norseman]

Nah, the narrow channel is a inch higher than the floor of the scupper well.

Ah, the advantage to being able to walk onto your boat at a moment's notice vs. driving to the yard, climbing over snowbanks, setting up a ladder, finding a tall person to unzip the zipper door in the shrinkwrap, etc., etc. Nah, not happening.

Good idea to try first with something removable. I wouldn't want to epoxy over the thru-hull fitting.

Yeah, one is spoiled, boat in the backyard..

Nah, would never epoxy over the thru-hull fitting, just raising the floor in front of it.