Deck reinforcing patches

[Guest]

I'm in the process of leading the reefing lines on my 25 footer back to the cockpit. I will need to add some turning blocks at the base of the mast, and some rope clutches by the companionway. I plan to strengthen the deck by glassing in some plywood reinforcing patches on the inside face of the coachroof moulding. The question is, how big do these patches need to be, and of what thickness of plywood?

 

[Guest]

12mm minimum

and at least double the footprint of the fittings you intend to put on the deck. The idea is to spread the load through as large an area as possible, so if you have the room, go for as large an area as you can. Glass the ply well in to exclude any moisture.

 

[Guest]

Re: also....

Also, make sure you bed the ply on thickened resin to completely fill any gaps between the ply and the GRP completely. With even a small gap, as you tighten the fitting screws you will distort the deck which may lead to cracking of the gell-coat.

And also, all of the above does not apply if you have a foam or balsa core in your deck. This needs a differed method.