recore the deck

[LookingForCruiser]

Hi everyone,

So I have a few delaminated spots in the deck, one of which is under a chock and requires attention before launch. So I'm planning on recoring these spots. The instructions in "This Old Boat" seem straightforward enough - however, one thing doesn't seem clear. The little diagrams always show the deck being cut exactly over the delamination. I'm guessing that's easier said than done - how do you know exactly where to cut? You want to cut out far enough that you get all the delamination, but if you cut into solid marine plywood core, the top layer of fiberglass isn't going to come off is it? It's all epoxied onto the wood...

Anyhow that's the mystery that's puzzling me today. I'll have another exciting question tomorrow, I'm sure.

Thanks!

[scottyt]

you can take a 1/16 drill bit and probe around till you hit solid wood and connection between the glass and wood. when you cut it out make sure you are only cutting the glass and very little wood. then cut the piece in half down the center, then you can lift it where it is delaminated then slip a thin bladed putty knife under the glass and slowly work the good lamination apart, and peel it up as you go.

after you get all the wet rotted stuff out soak the exposed wood in real thin epoxy. once you get all the new core cut to fit, wet the core, the bottom and top glass out with epoxy, then place put it all in place and cover with a plastic trash bag filled with sand. the trash bag will not stick to the epoxy that ozzes out. once cured take the bag off and sand back the epoxy that leaked out, fill and fair.

if you need to match non skid buy this stuff, you can then mix it up place it on a non damaged area. once it cures you can use it to match the non skid pattern perfectly if you place it right. if you really wanted you could make up enough "patterns" you could cover all the joints with it then put the sand bag over it. when done there would be just a minor clean up of the excess.

[LookingForCruiser]

Now, after the cut is made, I would presumably chisel the wood out so it's flush with the cut, and then use the cut-out portions of the top skin as the template to cut the replacement marine plywood.

My understanding is that I wet out the edges of the wood left inside the deck - I'd presumably also wet out the edges of the replacement core going inside the deck as well. Are there typically gaps left between the old & new wood, and I'm supposed to work thickened epoxy in there? Or does it just squish up & fill in all the way from the wetting out that I would be doing underneath the replacement core?

[jbondy]

I tried to do as Scotty suggested, but had a different outcome. First, though, I didn't drill as I didn't want to fill the additional holes. I sounded out where I thought the rot ended. After making the cut thru the top skin, I found that the rotten core extended farther than I had thought. I scraped out the additional rotten core leaving the upper and lower skins in place. I used 3 pieces of new core so I could slide it into the scraped out area and then fit the final, center piece in place. I thought this might be beneficial as the original, uncit skin layers were holding the edges of the core. I didn't like the idea of the cut in the skin lining up with the edge of the new core. I re-used the skin I removed as the top layer. I believe you are supposed to then grind the seam where you cut the top layer off and epoxy some glass into it to provide additional strength. I didn't do that and had no problem.

[Gary M]

You will likely have to add a little of your thickened paste to the sides but it will squish up around the edge of the new core. If you have access you can also do this job from below and not have to rework the top surface and try to get it looking right. I just did three spots on my deck from the underside and much prefer his method. It works very well if the area is not too big.
You can get a very solid laminations this way if you use the correct technique.

[jbondy]

BTW - Lots on this topic in this forum. For example, see:

http://www.sailnet.com/forums/gear-m...placement.html

[scottyt]

Originally Posted by LookingForCruiser

Now, after the cut is made, I would presumably chisel the wood out so it's flush with the cut, and then use the cut-out portions of the top skin as the template to cut the replacement marine plywood.

My understanding is that I wet out the edges of the wood left inside the deck - I'd presumably also wet out the edges of the replacement core going inside the deck as well. Are there typically gaps left between the old & new wood, and I'm supposed to work thickened epoxy in there? Or does it just squish up & fill in all the way from the wetting out that I would be doing underneath the replacement core?

i would not chisel out the good core, having the skin over lapping good core will be stronger.

as for wetting it out, yes wet everything out with epoxy. place the core which is wet on the lower skin which is also wet out, then use some thickened epoxy to fill any gaps, then wet out the top skin and put in place with weight. you also might want to use a slower hardener, as it can sit over night or a full day while you work on the next area. and yes it will squish up some if there is enough epoxy in there. thats why you want to use a large trash bags with sand, you want to have a 100 lbs on the area ( say a 2 to 3 foot area ) in several bags to make sure it get pushed down

[sailingdog]

There's an excellent article on doing this in a recent issue of Practical Boat Owner magazine IIRC.