Bottom damage

[Jim Kloss]

While sanding the bottom this morning I discovered a large crack running forward from the centerboard trunk at about a 30 degree angle from the midline. It was deep -- though the gelcoat and into the core. Obviously not a good thing.

A rectangular hard rubber (?) plug at the front edge of the centerboard trunk was also missing -- I've always wondered what it was for. Anybody know? If it's important, where can I find a replacement.

Is this repair just fill and seal, or does it indicate structural damage somewhere?

Jim Kloss
s/v Ambivalence
S2 7.9 #8

[dave]

Jim, it's a design and manufacturing defect in the boat. I repaired that same area about 18 years ago for the owner of the boat that I now have. The first time, I ground out about a 5-6" diameter area and the edge on the old laminate was ground to at least a 2.5 - 3" taper. I used West epoxy and Knytex fabric and even with that, the area cracked open again around one edge. Years went by and it was fixed again but poorly [not by me] and wasn't faired out properly so I need to do mine again for the third time. Do yourself a favor and go WAY out past what you think is adequate. I'm also going to use vinylester resin the next time. I have yet to ever have a repair crack or release with vinylester. Epoxy is always touted as the "go to" resin of choice, but not by me. Vinylester is actually stiffer than epoxy and is easier to work with and has a relatively long working time and then sets up quickly so you can get back to grinding and fairing much sooner. Cheaper too! I got some UHMWPE and cut a piece to fit for the bearing. I used 40 grit paper for the final shaping and left the scratches running fore and aft on the sides and front to help hold a bond. Nothing sticks to the stuff but with deep enough ROUGH gouges in it there is a strong enough secondary bond to keep it in place. As alway, wipe everthing down WELL with MEK before glassing or bonding for the best adhesion.

[Jim Kloss]

I repaired the cracks, which didn't seem as bad as I feared, sanded and painted the bottom. The repair looks good.

Ambivalence is still leaking however -- about a gallon a day! It's not coming from any of the through hulls or stuffing box. The water is salty, no oil but dark in color.

I think my next step is to pull the board to look for damage to the trunk; after that maybe put the boat back on the trailer, fill it with water and see if anything leaks out.

Any other suggestions?

Jim Kloss
s/v Ambivalence
S2 7.9#8

[Tom Elsen]

Hi Jim

Is it coming in (back) through the exhaust 'manifold' or the manual bilge pump exit?

[dave]

The best way to find most leaks is to put the boat on the trailer and use reverse engineering: remove the head floor hatch and put some water around the keel trunk if you think that may be the problem. If it is you will see water coming through around the trunk area on the outside. Just make sure that you hose in enough water to come up the side of the trunk a few inches to build some water pressure. Likewise with deck/transom leaks. Get inside the boat with the hatches closed and have someone spray a high pressure hose [NOT a pressure washer] on individual fittings.

good luck

[Roger Kuebel]

Two years ago I struck a ledge hard enough to pivot the c-board and force the aft edge of the board about two inches into the trunk/bottom. Several attempts at "professional" repair have not been completely successful (also had damage where top of forward portion of board went into trunk, but that repair was successful). I think I have pinpointed the source of the leak by sealing the cabin nearly ari-tight, pressurizing it, and watching where the residual water leaks out.

From inside the cabin, I removed the wood panel that covers the aft portion of the trunk so I could look down and see where the trunk joins the hull. There appears to be a stringer bonded to the hull athwartships right up against the trunk. I am thinking that it was possible that the board pushed into this stringer, letting water into the interior of the stringer, and if I don't get it completely dried out before my final repair I will be trapping water inside and will be creating another probelm.

Does anyone know the details of the construction of this area of the boat, or know anyone who does, or know anyone with experience repairing this area? Any help would be greatly appreciated.

[dave]

Nice job tracking things down Roger, I haven't been in there before. It DOESN'T sound like a very good place for wood. Before I finish with the rebuild on mine I think that I'll do like you and pull that aft section off and reinforce the whole area.