Voids around chainplates

[shard7]

I'm rebedding my chainplates after noticing some water intrusion, and was surprised to find that the top layer of the deck has a pretty large cutout around the chainplate itself. There was also some bondo-like filler surrounding it where the core should be, but it was weak and loose so I dug it out along with the surrounding soft core.




Does anyone know how best to fill this void beneath the chainplate cover? Planning to use through bolts and butyl tape to seal the cover, but need something solid in there for it to seal against. I was thinking perhaps epoxy with a filler to thicken it and add strength, or something like West System Six 10.

Thanks for your help!

 

[peaman]

First, the core needs to dry out pretty well. If you are able to fill the void completely, then thickened epoxy like West G-Flex should prevent further water intrusion into the core. I would consider using plastic wrap or something similar if necessary to keep the epoxy off of the chainplate, so the chainplate and deck can flex independently. Bolt holes in the deck should be countersunk to help prevent stress cracks and to improve sealing with the butyl tape.

 

[shard7]

First, the core needs to dry out pretty well. If you are able to fill the void completely, then thickened epoxy like West G-Flex should prevent further water intrusion into the core. I would consider using plastic wrap or something similar if necessary to keep the epoxy off of the chainplate, so the chainplate and deck can flex independently. Bolt holes in the deck should be countersunk to help prevent stress cracks and to improve sealing with the butyl tape.

Thanks for suggestions, very helpful! Regarding the chainplate, would a thin coat of silicone grease or wax (basically a mold release agent) be a reasonable way to keep it decoupled from the epoxy?

Drying out the core will be a challenge since the boat is outside in Seattle. We have a few dry days ahead of us, I may try to speed things up with a blow dryer from above and below. Anything else worth doing to speed up the drying process?

 

[peaman]

I think heat from the inside and cover from rain on the outside, with ventilation to allow warm air out, is the best you can do. If you have time, applying heat in multiple steps will get better results than all at once. That will allow deeper moisture to migrate to the newly dried area, for a more thorough drying.

I agree with your thoughts on decoupling the chainplate from the deck, if a clear gap cannot be maintained.

 

[shard7]

I dried it out as best I could, stuffing paper towels in there for an hour to soak up moisture worked well. Definitely not as dry as I'd like it to be, but hopefully good enough for a mid winter fix that'll last for a few years. I may drill some holes from below so that any remaining moisture has a path to freedom.

First batch of G Flex soaked in and spread nicely, will need to add a second batch tomorrow since the level eventually dropped below the top skin on two of them.

Thanks for the advice and pointers, not a fun job but worth it to keep the boat dry!

 

[Pete the Cat]

Thanks for suggestions, very helpful! Regarding the chainplate, would a thin coat of silicone grease or wax (basically a mold release agent) be a reasonable way to keep it decoupled from the epoxy?

Drying out the core will be a challenge since the boat is outside in Seattle. We have a few dry days ahead of us, I may try to speed things up with a blow dryer from above and below. Anything else worth doing to speed up the drying process?

I think you will be fine with your plan. Filling the gap with any thickened product would probably be fine. The chain plate is going through this and not clamping on the deck structures. Regular wax works for mold release and i agree that you want to keep it isolated so it can move. Butyl caulk is great.

 

[David Vaughn]

I think you will be fine with your plan. Filling the gap with any thickened product would probably be fine. The chain plate is going through this and not clamping on the deck structures. Regular wax works for mold release and i agree that you want to keep it isolated so it can move. Butyl caulk is great.

I'm about to start on the same project. How much movement should be allowed for, between the chainplate and the new epoxy filler (G-Flex)? Or will the flex in G-Flex be enough to allow sufficient movement?

 

[Pete the Cat]

I'm about to start on the same project. How much movement should be allowed for, between the chainplate and the new epoxy filler (G-Flex)? Or will the flex in G-Flex be enough to allow sufficient movement?

I think the gap needs to be only enough so that the deck is not involved with stabilizing the chainplate and rig. On some boats there will be flexing of the deck and the rig and you do not want them connected. My Tartan came from the factory with about 1/8" clearance, but you could fill any gap with butyl caulk and it isn't going to leak. I rebuilt a fiberglass Folkboat and had an irregular slot for the chain plates because of the angle needed to remove and reinstall them--I judged that it didn't matter. I made a SS slotted cover for esthetics. I have used G Flex but do not have enough long term experience with it to answer your question.

 

[shard7]

Ahh, sooo much better! Staying dry beneath despite the biblical rain Seattle received in recent days.

 

[peaman]

Ahh, sooo much better!

Very nice! The pictures also demonstrate one of the several great things about butyl tape over any of the tube caulk solutions, and that is clean-up of the finished project. The new install looks great.