vanity sink won't drain

[sailor]

I have recently purchased a Cape Dory 270. I found it in portland oregon and after a favorable survey decided to purchase. I am slowly working through the minor deficiencies but one has me totally stumped. The small oval sink across from the head will not drain. It has a plastic fitting underneath the bowl which is a 90 degree bend. The hose then runs parallel for a foot or so through the bulkhead and drops down to the through-hull. I can put water in the sink and place a rubber pipe in the sink drain of the proper size to fit tight and blow on it and can hear the air and water exit below the waterline. This sink is at least as far above the waterline as the kitchen sink, if not a little higher. Anyone else ever encounter this problem. I want to keep it as it has the really neat retro faucet handles, and also would be really useful being in proximity to the head.

[Jim Walsh]

That really sounds odd. There has to be an obstruction. I'd give it a shot with a mini plumbers helper. Sometimes the hydraulic action of plunging is better than the mild puff of air from your lungs.

[sailor]

I am going to the boat tomorrow and will try some things. The previous owner said he seldom used the sink but when he did he just stood on the port side and it would drain. Will report back.

[sailor]

totally dismantled the sink system. No obstruction anywhere. Even took a still wire and inserted it into the elbow at the through hull and let the water gush while I verified its' passage through to the outside. Don't understand it. I did fill up the sink and watched it drain. It does drain, but very slowly.

[tjr818]

It sounds as though the sink might be closer to the waterline than you think. What size drain hose does it have? Perhaps you could disconnect the hose from the sink and then start lowering it until you have water coming back in. That would give you a good idea of where the waterline in relative to the sink.

[Steve Laume]

Getting rid of the 90 degree fitting would help a lot. Not only does making a bend slow things down but the fitting itself, effectively reduces the size of the hose. You want nice sweeping runs with as few fittings as possible.

On Raven, the sink drains are very short and straight down to the through hull fittings, Steve.

[sailor]

I did check the water level with the hose disconnected from the sink and there is at least 4 inches to play with. The hose as I recall was 3/4 and a bear to get off. The elbow at the bottom necks it down to about 1/2".

[tjr818]

3/4" seems small to begin with, then necking down to 1/2" makes it pretty tight. What size are the through hull and seacock, and are they clear. 4" head isn't much, but it should be enough for water. Hmmm

[Astronomertoo]

3/4" seems small to begin with, then necking down to 1/2" makes it pretty tight. What size are the through hull and seacock, and are they clear. 4" head isn't much, but it should be enough for water. Hmmm

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I will bet on the seacock/valve exit being full of late summer blockage.
BC