Got a Leaker

[davavd]

I confirmed in the last few days that my boat is quite a leaker - about 1.5" in 30 minutes. I did a leak test today (not as hard as I thought) and discovered the leaks are all around the top of the daggerboard trunk and around the bailer.

For the bailer, I figured to just remove it and daub epoxy paste around the inside of the hole, concentrating on the joint between the hull and the cockpit. The bubbles in the daggereboard trunk seem to be all the way around about an inch below the deck, almost as if the fiberglass cloth was not full saturated with resin.

Since the water is coming from outside, it seems like the repair should be outside, not inside the hull. I'm thinking that maybe the way to do it would be to add just enough (filleting blend) thickener to some resin to make sure it doesn't run too much, and coat the inside of the trunk with this, using a foam brush with an extended handle.

I do have a port in the deck just forward of the daggerboard trunk, so if the above did not work, plan B would be wrap the whoe trunk, from deck to bottom with a lyer of cloth and epoxy resin.

If anyone has any suggestions, I'd love to hear them.

 

[Webfoot]

I used West Epoxy and Microballons to coat the bottom seam of the daggerboard well. I would not coat the inside of the slot like you mentioned because you will not be able to sand the area smooth once the epoxy is dry, ie. the daggerboard will bind up and get scratched. I only did the seam because I could get at it and smooth it with a file.

 

[davavd]

For some reason, it just occurred to me to pull up on the deck at the port while I had my other hand on the deck/trunk joint. I can feel movement between the two and see a crack when I pull up, so that's where its loose. I guess if water builds up in the trunk it could leak there. Feeling around the top of the trunk, I can tell there is a flange which you would think would be bonded to the underside of the deck. For the front 2/3, I can feel a gap of about 1/8" between this flange and the underside of the deck.

 

[Wayne]

I confirmed in the last few days that my boat is quite a leaker… and discovered the leaks are all around the top of the daggerboard trunk and around the bailer.

That daggerboard trunk separation sounds like the sort of extra damage using high pressure, high volume compressed air for a leak test would cause.

OK, water isn’t going to be leaking in at the top of the daggerboard trunk very much since that spot sits above the waterline. Most likely the water is entering where you found the bailer leak and the daggerboard leak is just exacerbating the situation by letting air out at a quicker rate than the cockpit vent hole alone would.

For the bailer, I figured to just remove it and daub epoxy paste around the inside of the hole, concentrating on the joint between the hull and the cockpit.

Epoxy paste will coat the outside edge of the bailer hole, but my guess is once the bailer is removed you’ll find a separation between the hull and cockpit you will want to re-bond deeper than just the edge. I think you’ll find a less viscous resin like WEST for fiberglass will wick in the crevice farther than just a surface coating would. You may even want to force apart the two shells slightly and run resin farther into the split for a wider bonding area.

Oh, and don’t forget, when you are finished with the repair work you need new gaskets on your bailer too.

The bubbles in the daggereboard trunk seem to be all the way around about an inch below the deck… I do have a port in the deck just forward of the daggerboard trunk... Feeling around the top of the trunk, I can tell there is a flange which you would think would be bonded to the underside of the deck.

My approach would be two fold, first I’d clean out all the loose and rough fiberglass along the flange in the trunk. I’d flip the boat and run resin into the flange joint letting gravity take it further in.
Second, I’d go inside the hull and wrap the flange joint with some turns of glass fabric. Unless you found evidence there are leaks all along the trunk, I don’t see a need to mummify the entire thing.

If you thicken the resin, I would recommend using milled glass fiber for strength, but not too much or you’ll inhibit the resin’s ability to reach into rather than bridge small voids.

Once the repairs are completed, air test again to be sure the large leak didn’t mask a tiny leak somewhere else.

 

[davavd]

Wayne, I can't thank you enough for your excellent feedback.

 

[davavd]

Crack at top of daggerboard trunk, port side (with deck pulled up

starboard

Here's what the top of the daggerboard trunk looks like below the deck, port side, looking aft

and starboard side

I've run a v-shaped dremel bit along the crack, and (with deck pulled up) filled the resulting groove with unthickened epoxy. I then removed the stick pulling up on the deck and set a weight on the deck above the trunk. Next step will be to lay glass fabric across joint between trunk sides and underside of deck, working through the 5" port. I'm not sure whether all that putty-looking stuff is the way it is supposed to be, but my repair is going to have to span that, i think.

 

[Wayne]

The putty looks suspicious. I've not seen that in other boats and it makes me wonder if this trunk wasn't repaired once before. What I am accustom to seeing is a smooth transition from deck to trunk. Does the foot of the trunk show signs of being cut down and re-wrapped to coinside with the putty layer at the top end?

I'm speculating the crack you just filled corresponds to the interface between the putty and the horizontal flange seen inside.