My Com Pac Sun Cat came with three cleats (a single bow and two stern) - I'd like to add two midship cleats to make tying up with springlines easier. I've done some searching on the web and the overwhelming consensus is to use backing plates rather than washers.
I've been in touch with Com Pac (an aside: they are great to deal with and always respond quickly to inquiries) who tell me that they don believe a backing plate is necessary. The reasoning is that two outboard bolts will go through the deck and the hull flange, where it is pretty thick and that they think the deck is strong enough for the loads from the two inboard bolts. The Sun Cat owners manual states the Com Pac uses a foam core (a "micro-balloon resin mixture") that the factory claims is far more resistant to water damage than balsa or ply.
I think that backing plates are cheap insurance and plan on using them even if the factory doesn't. Using butyl tape around the fasteners is a given, and I initially planned on using silcone sealant to complete the installation. This would be in line with what the factory does.
From what I can determine, potting the holes with epoxy falls into the recommended but not essential category. It requires a considerable amount of extra work, along with the purchase of a Dremel tool and some tips. Is the added effort worthwhile?
I've been in touch with Com Pac (an aside: they are great to deal with and always respond quickly to inquiries) who tell me that they don believe a backing plate is necessary. The reasoning is that two outboard bolts will go through the deck and the hull flange, where it is pretty thick and that they think the deck is strong enough for the loads from the two inboard bolts. The Sun Cat owners manual states the Com Pac uses a foam core (a "micro-balloon resin mixture") that the factory claims is far more resistant to water damage than balsa or ply.
I think that backing plates are cheap insurance and plan on using them even if the factory doesn't. Using butyl tape around the fasteners is a given, and I initially planned on using silcone sealant to complete the installation. This would be in line with what the factory does.
From what I can determine, potting the holes with epoxy falls into the recommended but not essential category. It requires a considerable amount of extra work, along with the purchase of a Dremel tool and some tips. Is the added effort worthwhile?
Last edited: