leak around 360 degree light on the Tom Cat.

[thataway]

We have occasionally noted a rare drop or two from the place where the wiring to the 360 degree "steaming/anchor" light, when we have a heavy rain. On the Tom Cat this is put on the aft top of the roof, which is cored with end grain balsa.

Today, we decided to eliminate this minor leak. No surprises here:

1. Bostic sealant was used to seal this--it was not effective.

2 The balsa Core had rot in it, both around the large hole, and the screw holes.

3. There is a hole in the bottom of the Perko fitting, which allows water to go into the area sealed off.

4. There was no epoxy sealant around the 3/4" hole (only 1/4" hole was necessary)--or around the screw holes.

The Bostic was still elastic, and it took a fair amount of pressure to break the Perko fitting free. I removed the screws holding the wires in the cabin roof inside, to free up the wiring. I removed the "vent" cap on the underside of the cabin, which hid the wiring exit and sealant.

There was rot in the balsa core--with wetness to the screw holes. I used knife blades, dremel tool bits and removed all of the wet and rot balsa core (about 1/2 to 5/8" beyond the center hole). I used a heat gun to be sure that there was no residual water. I then ground out the screw holes to 1/4", and undercut the balsa, with grinding a fresh edge on the fiberglass layers. Then I mixed medium density filler and cabosil with eopxy, and filled all of the area where there had been rot (I actually narrowed down the hole, to about 1/4", in the center.) After I let this epoxy set up, then I drilled out the center of these screw holes. The area was filled with fast set 4200, and then the plate put back in place. I also filled the "drain hole" with 4200--and probably will drill out a hole to the outside, when the sealant sets up.

Hopefully this will resolve this only leak in the Tom Cat 255. I suggest that all Tom Cat owners, or any one who has a cored center top, where the light fixture goes through this cored top, check it. If it is OK--then rebed with 5200, and seal the edges with epoxy. If it has water intrustion--then do the complete repair.


The photos shows the large hole, with glass on top and bottom, void where rottena and wet balsa removed. There is also a screw hole, before it is drilled out and filled.

[Captains Cat]

Thanks Bob. I'll check mine as I'll bet all the TC folks will as well.

Charlie

[matt_unique]

I removed the interior and exterior screws to the light/covers. I could not see any evidence of water intrusion inside under the clamshell.

On the outside the plate was very snug against the roof. When I pried the plate up I could see the entire thing appeared filled with a white compound, probably Bostic. I was concerned about pulling on the wires. I rebedded the exterior screws with Fast set 4200.

Bob - did you have to remove everything (i.e. all the bostic) to see evidence of water damage? I have never noticed water dripping inside the cabin (though I have found a little water right in front of the door inside with no apparent source).

[BrentB]

Bostic the nemesis

Did removing it take more time than rest of the repair?

[Minnow]

Worth noting, as it happens on the 25's and probably all the rest, is that even with a proper perimeter seal around the mount, is that water can still enter through the gap between the plastic collar and the mast.

If you don't much night cruising, leave the cap on instead of the light mast.

[localboy]

Just one more reason to eliminate the [front] Perko light ( which is my anchor light only) and re-wire the all-around white on the radar arch ( which is the running light) for both uses on 'Au Kai.

[Levitation]

Bob, I am planning to offer the new owners of C-DORY the chance to have you inspect the first new boat they build...
I bet with your experience you can find stuff that needs improvement that they don't even know exists...
That could be their new advertising shtick - a big indelible ink stamp on the side of the hull that says 'inspected by BOB'.
denny-o

[thataway]

Matt,
Yes, I removed all of the Bostic. No more leaking. Of course we have from 65 to 85 inches of rain a year down here, so it does get a real soaking.

I have just left my LED light and cap in place. I pretty well sealed the area around the pole/tubing, as well as beding down the Perko fitting properly

I doubt if Sea Sport wants my suggestions...If they ask, I'll be happy to send them a long letter..but am not holding my breath. These problems are not unique to C Dory. Although I have looked looked at a number of C Sports (including the nice 32 cats), I didn't look THAT closely...

[marvin4239]

I had a lot of problems with my all around light not making good contact that I finally replaced it with a hard wired folding LED light.

When I removed the old light it hadn't leaked but I really don't know why it didn't have any sealant what so ever. My roof hand rails have all leaked and I've got to take them off and seal them up.

[/img]

[matt_unique]

I was concerned about lifting the pole fitting too far and pulling the wires. There is no slack in the wires inside. How did you address this? Were your wires flat and mounted snug (without apparent slack)?

Mine is really bonded down and takes considerable effort to pry under with a screw driver.

[thataway]

Matt,
There was not a lot of slack, but as you can see from the photo, I was able to get the Dremel bit in and route out the core. I covered the wires and under the area with tape and Sarin wrap when putting in the Epoxy filler.



As you can see in the back of this photo, the wires come out of the head medial bulkhead, and there was enough slack to work with them.