Marine Trader Question

[Autoteacher]

We have a 1986 Marine Trader 40 ft Sundeck model.
We have lived aboard for the past 3 years slowly rebuilding this neglected boat.

We now have a problem we discovered when we cleaned and paited the bilge in front of the holding tank and aft of the holding tank is a shower sump then another bilge . We note a small amount (less than a half a cup in 24 hours) of clear sea water in the aft shower sump the aft bilge is dry. this is not draining from shower or the AC drain, BTW. The forward of the holding tank bilge is showing a tablespoon of seawater also, no smell so the holding tank is not leaking. This seawater is tan colored like weak tea. We cleaned the bilges, scrubbed the old loose paint and dried them out, poured Rot Doctor CPE in and let set overnight. So all the screw holes from previous pump and switch installations were filled. Then we painted the bilges with Rustoleum marine grade white paint. The two small water amount still leak in. They seem to appear at the seam where the holding tank meets the hull. Any ideas? Experience with this problem? Recommend solutions? Our next planned haul out is Dec 2014. Last haul out and diver saw no problems. I suspect the keel is leaking from a crack or damage to gel coat. Does anyone know how the keel is constructed on these boats?

 

[Capt Kangeroo]

It wouldn't be a crack in the gel coat, it's not structural but could be a crack in the glass itself if you hit something hard enough. Possibly an area of delamination but I think it highly unlikely. The hulls on those Traders are built like tanks, solid glass & ridiculously thick. I did see something similar on a friends boat where he had a small leak along the keel, it turned out that the last layer of glass applied in this area did not stick to the previous layer (dry bond) and the water was actually coming in at a thru hull and traveling between these two layers of glass and coming out a couple of feet away at a seam.

Just a thought and something to watch for.

 

[Moonstruck]

It would be hard to tell where it is coming from, but the tea color sounds like it is coming through some rotted wood. There should be a stain trail somewhere from where it is breaking to the surface. However, like the prior post said, once inside the laminate it can travel in hidden ways. Good luck.

 

[Ski in NC]

Is it a cored bottom? If not I would not worry too much. Seems more of an annoyance. If cored it could be turning into a swamp.

On one boat (not MT) I put a through hull fitting in and the plug from the hole saw came out in two pieces. There was a layer of sawdust between them!!! They put layers of glass over sawdust!!

Chasing that leak can be a PITA. Water definitely moves around. Leak could be a good distance away. Trying to plug it from the inside won't work as the hydraulic pressure will force water into your patch. Gotta do that on the hill, or from the outside if you can find it.

Edit- saw it was not cored bottom.

 

[yo]

I would think that you may have a leak in your shaft log, (pin hole in SS) and that will let water into the keel which will find its way into the bilge. just a thought.
mike

 

[psneeld]

picture would help..if not, might be in Jekyll Island on the 12th if you want me to take a look.

 

[Autoteacher]

Thanks for everyone that replied. After a great deal of thought on what you said I slowly reevaluated the problem and discovered the the water came from the port side shaft seal that is not dripless. The design was to allow this water to drain to the forward engine room bilge. But a overlap of fiberglass did not quite make a seal on the stinger and water seeps under the holding tank. I assume the clear water aft travels only a short distance and the tan water forward travels under the Holding tank long enough to become discolored.
Thanks again for thought provoking insight. You are the value of the forum!

 

[boatpoker]

Associating "tea" colour and an unsealed stringer requires further investigation.
As Moonstruck said, that colour is normally associated with water coming through wood.
Suggest you take a very close look at the core of that stringer and ensure it is sound and dry.

 

[alormaria]

Tea colored water is never good on a Marine Trader.