Mainship 430 slow galley sink

[BSwindale]

The double galley sink on our 2007 Mainship 430 drains slowly. The water backs up into the other side of the double sink while draining. I checked the trap, and forced water from a hose through the drain line, which seemed to flow clear. Anyone have any suggestions?

 

[Dougcole]

The galley sink on our 400 airlocks sometimes. Use a clean toilet plunger to clear it.

 

[Comodave]

Where does the drain go? Does it go into a sump or directly overboard? I am not sure why you would even have a trap in a boat since the purpose of a trap is to block sewer gas in a home. The trap may be part of the problem. If it drains into a sump the trap may block smell from the sump.

 

[BSwindale]

It drains directly overboard, after being joined by the drain from the wet bar on the the fly bridge. I’m not sure why the trap is there either. Maybe to keep critters out? My head sink and shower dumps seem to go to this device, then overboard. I can’t see if the galley sink has one of these. Is this just a manifold of sorts, or something else?

 

[Mac G]

Where does the thru-hull exit for those fixtures?
Above the W/L or below the W/L?
If above, then something must be blocking it.
But if below, then it just takes time for the water level in the pipe to equal the water level of the hull, especially if the boat is not moving.

 

[BSwindale]

The thru hull is above the waterline. I have flushed it with a pressure hose from the dock, and it seems to flow well. I may just have a low spot in the drain hose. Just wondered if any other Msinships had a similar issue

 

[Mac G]

That situation is common on sailboats and we have it too on our GB42 - the forward head sink exits above the W/L and is fast whereas the aft head sink exits below the W/L and is slow if boat not moving through the water.

Aft 50+ years as a sailor we switched to trawler life 2 years ago. One of the first things I did, pre-purchase while on the hard, is identify and locate every single thru-hull fitting so I could inspect them and see what they served and know how to get at them in an emergency.

Turns out our GB42 has a total of 27 thru-hull fittings between above the W/L and below the W/L, not counting vents. I recognized the aft head sink as a possible issue, which is indeed the case.

 

[Mac G]

Sorry, was typing my follow-up before I saw your reply.
If above W/L then will suggest you rip out and replace with new hoses and forego any sort of unnecessary trap situation.
Hoses can gum up overtime, especially a galley sink where who-knows-what may have been dumped through there over the years.
Start clean and fresh.

 

[BSwindale]

I think I found the issue after removing the back of a cabinet The drain hose takes a big dip down, then back up, then another small dip down before the thru hull. I'll try to raise it to a gentle slope. New hoses are probably a good idea too. Thanks all for your input.

 

[C lectric]

THe sink hose should go down to the exit overboard, NEVER up or that UP will act as a trap and hold stinky material.
THat mfld. looks home brew and its up to exit configuration is haywire.

Rearrange the connections so all of them enter any mfld. downwards. Use Y tees or simply redesign so all connections point down to the mfld.

But get rid of that mfld and arrange all the connections so they point down even if you must redesign including the hoses themselves..

 

[hmason]

FYI, the admiral once dropped a diamond ring down the galley sink. Thank goodness for the trap. Don't leave home without one!

 

[BSwindale]

Thanks all. I’ll try to reroute the galley drain, have to pull the fridge to get to it. The manifold in the photo is for the lav sink and shower sump pumps. The pumps struggle to overcome the pressure head of the rising hose. I think this is a factory install, right now I don’t see any way of reaching it. That could be a future project!

 

[Cartouche]

The double galley sink on our 2007 Mainship 430 drains slowly. The water backs up into the other side of the double sink while draining. I checked the trap, and forced water from a hose through the drain line, which seemed to flow clear. Anyone have any suggestions?

Happened to us on our 390 we were portside docked and the fender was covering the drain hole, it is a straight run overboard from the sink

 

[Comodave]

That’s why they make reciprocating saws…

 

[Delta Riverat]

FYI, the admiral once dropped a diamond ring down the galley sink. Thank goodness for the trap. Don't leave home without one!

Yeah, I thought about that. Checked to make sure there was a guard in the drain fitting that would not pass the ring because they all go straight to the through hull. Fast too, you turn on the water and you hear the splash outside in 1 second.

 

[AlanT]

Check for a blockage in the line. Our brand new Hylas 49' had a similar blockage which we eventually traced down to construction debris in the drain plumbing. By this time we had installed an inline mascerating drain pump which we actually embraced and used to drain the sink since it exited below the waterline and it could push the standing water in the plumbing out of the boat, preventing stinky drain water loitering in the standpipe.
~A

 

[DrissZougari]

Is that a treaded cap (for cleaning) at the end of your contraption?

 

[Comodave]

A friend of mine had a DeFever that had a below the waterline drain on the sink. I think that they did it that way so there wouldn’t be stains on the hull side but it was constantly getting plugged up with marine growth.