Any Mainship 40 owners here?

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DXM

DXM

Newbie
Joined
Jul 29, 2018
Messages
2
Location
Sarasota, FL
I’m looking for any advice. I have a 1994 Mainship 40 and the front bilge is constantly full of water. Every 4 days I can manually pump out about 10 gallons. However the level never rises enough to turn on the float switch! I’ve spent countless hours trying to research and found that the ac pan drain drops right into the bilge. This weekend I replaced the shower sump and plumbed the forward ac into it. I also removed the holding tank and now the water level rose! But still not enough to activate bilge. When I manually run bilge the level barely changes mainly because the pump air locks and the water comes back down the hose. I tasted the water and it had a faint salt taste but that could just be residue. The boat was just splashed 2 weeks ago after a new bottom job, and forward of this bilge there are no below the waterline holes and no thru hulls. The 2 thru hulls in the bilge have sea clocks closed and they are not leaking. I am able to vacuum area dry and within 12 hours it is filled up again. Any ideas? Boat was just surveyed last month and no hull issues were found, not even blisters. Could a Norcold fridge be the culprit? Since it appears the factory ran the ac drains to the bilge I’m guessing the fridge could do the same, but would it produce that much water? I have ripped up the entrie floor forward of the galley and cannot find any water. All areas are dry. :banghead:
 
We have an older MS 40 but the bow is actually the lowest point when sitting at the dock. I've re run the aft ac drain and the stuffing boxes will contribute a little water when underway ( or maladjusted). Unfortunately it could be anything. Rub rail, deck fittings, loose hose clamp on a fw or sw line. I think your best best would be to try to trace it back. Vac it dry, wipe it dry, and see where the trickle comes from. Watch the inside of the hull too, especially after a rain. Good luck
 
I have a Mainship 400 , 2007 with a similar problem. I built a dam with plumbers putty fore and aft of the forward sump and found the water was coming from towards the bow. Water appears to be fresh. I get about a gallon a week even when the weather is dry and nothing running but the fridge, when tied up at the marina. I too am stumped as to where the water is coming from.
 
You should probably specify that you're discussing a Mainship 40 "Sedan Bridge" and not a Trawler. Mainship made both. Just my .02
 
Mainship 400 trawler

Shrew said:
You should probably specify that you're discussing a Mainship 40 "Sedan Bridge" and not a Trawler. Mainship made both. Just my .02
Click to expand...

Not sure if you were referring to my question or the previous one but my Mainship 400 is a trawler, not a Sedan Bridge design.
 
I'm not familiar w/ the 400 design details...

Have to wonder - if they plumbed AC Cond drain to bilge what about anchor locker drain?
 
I had water in my fwd bilge, traced to bad shower sump pump. The sump box was overflowing into the bilge.
 
jemcne7 said:
Not sure if you were referring to my question or the previous one but my Mainship 400 is a trawler, not a Sedan Bridge design.
Click to expand...

The statement was directed towards the OP.
 
You might try putting some paper towels in the forward bilge up on the sides to see if they get wet. Another trick is to dust talcum powder on the sides to see where the water is draining into the bilge.
 
We have a dehumidifier that we leave on and sitting in the shower (drains into the shower). I read in the Mainship manual that the (closed) shower sump required the head breaker to be on, so assumed it was overfolowing into the forward bilge and I had solved the mystery.

However testing that proved not to be true, as the shower sump turns on automatically even if the head breaker if off. So still searching for a solution :(
 
Mainship 40 Sundeck 1986 Wandering Star

Hi Everyone, We're new to this Mainship forum. We bought her last July. She needs some work on some of her systems, but all in all she's in good shape. We'll look forward to chatting with y'all as we spruce her up more. In the meantime, safe travels.
 
Shrew said:
You should probably specify that you're discussing a Mainship 40 "Sedan Bridge" and not a Trawler. Mainship made both. Just my .02
Click to expand...
Ours is a 1986 Sundeck model, and we have had none of these problems. Just a few others.
 
We had a MS400. Problem turned out to be a clogged condenser pan drain under the Salon AC below the helm station. Condensation would come over the lip of the pan.
 
sedan bridge bilge issue

Just curious if you figured anything out, I have the exact same problem with my 1994 sedan bridge.
 
Water, water...from where?!

Try process of elimination.
It’s likely fresh water is plumbed throughout the boat. (My 350 has fresh water plumbed to the bow anchor washdown as well as the head, and the hot water heater is under the side-cabin berth)
Check for pressurized water system leakage- disconnect dock water feed (don’t trust the valves) overnight and when away, compare water accumulation results with previous. Make sure to switch off the Fresh Water Pump as well (which should not be on if you are on dock water)
I had a problem with my fresh water tanks self-filling to the point of overflow: turns out the Fresh Water Pump (Jabsco) by-design provides a ‘check valve function’ which was leaking dock-pressure water back to the tanks! When I replaced the pump I also added an in-line check valve to prevent that problem.
Localize the source. Monitor all bilge areas, (I have 3 bilges/pumps, plus an isolated bilge under the engine with no pump) use colorant/food dye to determine water migration, dip paper towels to check for color, etc.
It’s a game
 
Water in Bilge

DXM said:
I’m looking for any advice. I have a 1994 Mainship 40 and the front bilge is constantly full of water. Every 4 days I can manually pump out about 10 gallons. However the level never rises enough to turn on the float switch! I’ve spent countless hours trying to research and found that the ac pan drain drops right into the bilge. This weekend I replaced the shower sump and plumbed the forward ac into it. I also removed the holding tank and now the water level rose! But still not enough to activate bilge. When I manually run bilge the level barely changes mainly because the pump air locks and the water comes back down the hose. I tasted the water and it had a faint salt taste but that could just be residue. The boat was just splashed 2 weeks ago after a new bottom job, and forward of this bilge there are no below the waterline holes and no thru hulls. The 2 thru hulls in the bilge have sea clocks closed and they are not leaking. I am able to vacuum area dry and within 12 hours it is filled up again. Any ideas? Boat was just surveyed last month and no hull issues were found, not even blisters. Could a Norcold fridge be the culprit? Since it appears the factory ran the ac drains to the bilge I’m guessing the fridge could do the same, but would it produce that much water? I have ripped up the entrie floor forward of the galley and cannot find any water. All areas are dry. :banghead:
Click to expand...


One suggestion would be to get some food coloring and put 1 color in forward AC drain pan, another color in main salon AC pan, another color in a bucket of water and pour into anchor locker. Do one at a time and inspect bilge after a day or so after each treatment. Using different colors helps keep items separate. I use this trick at my rental properties when I suspect a leaking toilet. A couple of drops changes 3 gallons of water. Yellow may be difficult to see, but give this a try.
 
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