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J/35 poor bilge drainage.


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I don't know if this is common on j35s or not, but the links between the bilge compartments on my boat were done very poorly! The holes linking the compartments were goobered over with fiberglass and gel coat which causes them to clog easily and not drain very well at all. As a result, I get a lot of standing water from my prop shaft seal which must also be allowing microbial marine life in to the bilge, which then in combination with standing water makes for some pretty disgusting stuff that grows in there without ever being able to make it to the bilge pump.

 

I've taken a round rasp file and opened up the holes and tried to work them down to allow for better drainage, but the compartments themselves are not designed well and unless they go really crazy with a grinding (which I'm afraid to do) they will retain standing water as the holes connecting the compartments are too high up by design.

 

What I'm thinking to do is to dry the compartments entirely and scratch them up with like a 60 or 80 grit sandpaper to help an epoxy mechanically adhere to the bottom of these compartments. The idea would be to fill them up with epoxy so that once the epoxy hardens the compartments can actually drain properly.

 

Before I do something stupid, I wanted to run this idea past you guys and also ask are there any other solutions that I'm not thinking of? And what epoxy could I use for this purpose that would actually adhere and due to the sheer volume that I need, be somewhat cost-effective.

 

@Bump-n-Grind@Great White your input is welcome.

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I'm kinda with SL on this one. my boat doesn't really have that problem. my little electric pump can never get the last few drops out of the lowest part of the sump, but whatever water comes in the boat either thru the shaft log or the rig or the 1000 other places that water comes in always finds its way to the bottom. I keep a good sized household demudifier on the boat and that seems to collect and pump out the galley sink drain, whatever the bilge pump can't get...

does your boat generally sit correctly on its lines?

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@Bump-n-Grind

I think it is sitting properly. The boat would have to be very deep by the bow for that stuff to even half drain.

I will say that my drainage passages from the v-birth are horrible too! I've lifted up the covers to find probably about 10 gallons of standing water there once and the passages are so caked with gel coat and other at factory defects that I can barely squeeze a coat hanger through to unclog small contaminants and get it to drain at a trickle. I don't know how to safely address that problem because I've not been able to trace where the v-birth is draining to. It appears to be going straight to the main bilge and not to the bathroom compartment.

But now that I am aware of the issue, I just keep an eye on it and make sure that the trickle ports are open. My biggest problem right now is with those rear compartments because the standing water is causing things to grow and it stinks up the cabin which makes it unpleasant for female company ;-)

 

So, any recommendations on how to address it? Or what is the cheapest by the gallon epoxy that you can think of?

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TPI built J's had air dry gel coat slopped on after everything was tabbed together. Limber holes were drilled just before gel coat applied. So they could not get the holes down to the bottom of the stringer, and gel coat lakes make it worse. I have gone thru quite a few J's of this vintage with a Dremel (or similar) grinding the holes down to the hull laminate. That helps a lot - the other trick is to store all the loose gear in the forepeak to get the bow down. This gives those aft sections some slope to get them to drain - there is enuff rocker in the bow that those sections will still drain. But a wet/dry is still the easiest/fastest method to keeping those bilges dry.

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3 minutes ago, longy said:

TPI built J's had air dry gel coat slopped on after everything was tabbed together. Limber holes were drilled just before gel coat applied. So they could not get the holes down to the bottom of the stringer, and gel coat lakes make it worse. I have gone thru quite a few J's of this vintage with a Dremel (or similar) grinding the holes down to the hull laminate. That helps a lot - the other trick is to store all the loose gear in the forepeak to get the bow down. This gives those aft sections some slope to get them to drain - there is enuff rocker in the bow that those sections will still drain. But a wet/dry is still the easiest/fastest method to keeping those bilges dry.

and that, dear friends, is probably why I don't have this issue.. there's a metric fuckton of stuff/sails piled up in there. as for draining the forward cabin/shower sump, that did clog up on me a few years ago and about 3 seconds with a pressure water aimed into the limber hole under the forward bunk blasted that channel clear and it drains freely now. I blast a garden hose spray nozzle thru there once a year just to keep anything from accumulating in that channel.

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I have the same issue in my Alerion Express 28, also by TPI.
If attempting to clean up the limber holes with a Dremel or die grinder, should I assume that the hull laminate is continuous under the floor ribs?
Wouldn’t want to breach the encapsulation of the balsa.

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Are the stringers part of an inside laminate that collects water that drains out through the limber holes? 

If not then I'd be tempted to dry out the bilge, epoxy fill the limber holes entirely, give the whole lot a thorough clean / key and paint and then leave as is. 

I personally quite like the fact that bilges on my boat aren't linked as it lets me pinpoint leaks, & in general modern fiberglass shouldn't really be getting water in the bilge other than from keel stepped masts / old school engine packing glands. 

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I race the boat, so loading up the peak with ballast sounds like a terrible idea. My holes are really high up and I am concerned with grinding any more than what I already have due to fear of grinding through the encapsulation and causing a bigger problem. 

I think I'm going to go with the epoxy route. Just placed a $220 order for 6L of epoxy (probably 3x as much as I need, but I don't want to be short and I can use it on other projects) and I am going to just fill the bottoms to the level where they will drain properly. 

@Bump-n-Grind you might have another story to tease me with for the next decade...

https://www.amazon.com/EcoPoxy-FlowCast-Casting-Working-Counters/dp/B0829T7Y5D

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dont mean you keep it up there while your racing, just when the boat is parked in the slip or cruising if you need the space in the cabin. it's part of pre/post race drill to move the bags in and out of the forepeak and sorta arrange them in the order they might get used during a race. 

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I still think you'd be better off grinding the holes down to meet the sump base and then sealing them up good with epoxy than filling the base up with epoxy to meet the holes... but do what ya want, it's not my boat :wacko:

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Yes, putting weight in the bow is only for storage when sitting at the dock. Move it all to appropriate spots when leaving the dock. If you insist on filling the bilges - do a test to see how well it self levels first - I think you'll need to brush out the edges to get a flat join. And weight the boat aft just a bit when pouring to achieve a downhill slope to the pour once it's hard.

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3 hours ago, Bump-n-Grind said:

I still think you'd be better off grinding the holes down to meet the sump base and then sealing them up good with epoxy than filling the base up with epoxy to meet the holes... but do what ya want, it's not my boat :wacko:

I'd be inclined to epoxy some rigid tubing in the holes to keep the laminate isolated.

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16 hours ago, SloopJonB said:

I'd be inclined to epoxy some rigid tubing in the holes to keep the laminate isolated.

This...but with flat bottomed race boats, a small wet dry vac & a good sponge and bucket are the best answers 

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Might want to consider using filler in the epoxy in the bilge sections you are cambering for better drainage.  Straight epoxy is heavy, and somewhat weak compared to epoxy plus fillers.  Maybe light fairing filler as it's easiest to sand, and you'll be doing some sanding/grinding to get smooth straight cambers that get the water to flow where you want it. Probably won't need multiple quarts of epoxy either.  

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