Water tank on a compass 29

[Herreshoff]

Hi,
We are trying to trouble shoot a problem with the built in tail water tank of a compass 29. The tank supposedly holds 120litres however even when empty (we know because we've removed the hoses and put a rope down which came up dry) the tank isn't accepting any water. It just overflows after 10 litres. Any ideas?


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[JPA Cate]

If you have one, could you post a plan of your boat?

Personally, I am not familiar with the Compass 29 "tail tank".

HOwever, if there is a lot of water that you did not put into that tank, I'd think the first thing would be to empty all of it--and you may need an external pump to do this.

If you're brave enough, taste test the water. If it's salty, somehow your're getting ocean water into it. Check EVERYwhere salt water could get in.

If it is not salty, pump it all out. If possible, clean the tank, make an aperture if necessary. Then check carefully all hoses and their clamps, then fill the clean tank.

Be sure to test the water at this point, to make sure it is okay.

Household bleach, in the ratio of one tablespoon to ten gallons is adequate to kill biota in fresh water. You will need a charcoal filter, then, to filter out the chlorine.

Ann

[Snowpetrel]

I am guessing it's a keel tank? Anyway, might be a breather issue? Weird that the ropes dry.. My first thought was water trapped in the fill and return lines acting to stop the air getting out, but a dry rope might disprove this. Best bet would be to remove the fill pipes and fill it with a hose from inside directly into the tank. Ideally cut an inspection hatch into the top of the tank. Good for cleaning, and other things. Another thought is the tanks full and it's a pump suction issue?

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[Herreshoff]

Thanks for the responses.

We're fairly sure the tank is empty. Firstly the water pump is pumping dry and by putting the rope down into the tank and it emerging dry I'm fairly sure there is nothing in it.

I'm beginning to think it is a breather problem as well. I can't find a breather pipe or a valve anywhere. On my own boat, (not the compass) air blasts out of the breather on deck with enormous force. I was wondering if the same type of breather valve could be added like the ones we use in plumbing for the head? The ones at the top of the loop.

I began to double guess myself because the water input hose (which is large in diameter) would surely allow air to escape and thus mean that it's not a breather problem. The only way I can think it would not allow the tank to breath would be if the input hose exits deep into the tank at a point where there may be some dregs of water left over. Therefor the air would not be able to escape. I theorise. It's a head scratcher.


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[Herreshoff]

Oh. Yes it's a keel tank. The hose input/outputs are under the engine making close inspection difficult.

As to the tail tank reference. I've never head it called a tail tank either however that's how they refer to it on the compass website.


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[Snowpetrel]

Can you try filling it backwards via the outlet pipe? See if air comes out the filler.

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[Herreshoff]

Good thinking. It's night time here in oz so will try tomorrow morning.


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[Djarraluda]

Same basic arrangement as the C28 with the aft end of the keel glassed-in.
Must admit it has always been a keel tank to most of us, never heard of a tail tank before, but it is descriptive enough to indicate what you mean.
Lots of the boats (28 and 29) have cut a 100mm dia inspection hatch under the engine, but not a practical solution with the engine in-place still.
I assume you are also looking at the Forum on the Compass site on Google Groups. We are quite active there , especially for the 28 and 29s.
Most likely cause is a blockage in the fill pipe. I assume you have the standard arrangement, with a 1 inch flex hose from the top of the tank, straight up to the bridge deck mounted filler. There were a lot of boats home completed, so the inlet pipe may even be taken down to low level in the tank. I wonder if the pipe itself is deformed, but then you say you have removed it already.
Try removing the outlet hose, which has a fixed dip pipe inside the tank, dropping close to the bottom. Then use bellows from an inflatable boat or similar to push air into the tank. Cover your eyes but keep close and listen as well as watch. Weird gurgling and other strange sounds indicate an excess of sludge. Boats of this age tend to accumulate such.

Roger

[mitiempo]

Originally Posted by Herreshoff

I was wondering if the same type of breather valve could be added like the ones we use in plumbing for the head? The ones at the top of the loop.
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The type of anti-siphon used in head plumbing won't work - they let air in, not out.

[Jim Cate]

Perhaps the previous owner put a large poly bag of white powder in that tank and forgot about it. Now there iis only enough room for 10 litres of water...

Jim

[Herreshoff]

Well that scenario we can live with.
Who needs water.


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[Dave22q]

I assume you say its full because the fill pipe overflows. as the tank is really empty the problem almost has to be in the fill pipe. try pumping air into the tank outlet and see if you can blow out the obstruction. stay clear of the fill pope when you do this.