Relocating a galley/ thru-hull question

[Westerly23]

Hello,

I would like to relocate our galley sink aft. The idea location is right above a cockpit drain thru-hull.

Is it acceptable to Y into this thru-hull for the sink drain?

Do you forsee any issues with this?

Thanks.

[ted655]

Is there any chance of backflow between the two drains? Which drain has the higher originating point, the cockpit? If so, then the p trap on the sink should block any oders or backflow as long as there is no back pressure at the discharge point on the hull.

[Westerly23]

Is there any chance of backflow?
Yes, from the sink into the cockpit, but the thru-hull is much lower than the cockpit, so it should'nt be a problem.

The galley sink is the higher of the two.

I would retain the shut off for the cockpit drain, this should elimitante soapy water from backing up into the cockpit while at the dock.

[ted655]

I always thought of the cockpit as having a scupper flap. Interesting that it has a shutoff. One more thing to remember before setting sail, open the cockpit drain.
Fewer hull holes the better, no? I don't see a harm to your idea.

[FAST FRED]

Bite the bullet and give the sink its own thruhull .

When grease or something plugs the discharge , it can be disconnected at the sink and the hose straightened out.
Then a broom handle can clear the blockage , and the hose returned to the sink drain. No need to touch the seacock if the hose ends above the water line.

FF