Deck Recore

[Ajay73]

Last week I cut into my deck under a turning block because of some wet plywood when drilling out one of the holes. I figured I would cut into the laminate directly under the block (about 2" X 6") to see how far the dampness had spread. Well I ended up with about a 6" X 7" cut into the fiberglass and there is still more damp wood to be repaired. The area I was cutting into is in line with the mast, beam direction that is, not for and aft. Come to find that Catalina put in 2 1/2 " of plywood in there(what were they thinking?). I'm sure that there is this much plywood all along the line athwartship of the mast as you can see the form the headliner takes on the inside of the boat. I suppose they were building up the thickness to support the mast. Not sure they need this as they have a compression post to handle mast load. I wished they would have tabbed in a wood beam on the inside of the boat or someting else more easily repaired. I dug down to the bottom skin which forms the headliner inside the boat. This headliner is quite thick. I would estimate it to be almost a quarter inch and quite solid/stiff. I ended up putting in 5 layers of 1/2" marine plywood, epoxied in place. I have a lot more work to do. I'm sure the area under the mast is wet. They have mast head light wiring running through the mast step plate and runs in between the inner and outer skins and I'm sure water has gotten in through the wiring opening. The wood I dug out was damp but not rotted. The area around my mast does not show any signs of compressing into the fiberglass. This was the same thing I found when digging out the inch and a half of plywood from the keel sump, wet but not rotted. Catalina sure loved to put in a lot of plywood. It'll be enjoyable to get into the area where there is a normal deck core thickness. To be continued.

 

[Barnacle Bill]

Catalina hasn't been known to be one of the best built boats in the world and this is one reason why. Some manufactures of even earlier designs used to put plywood between the keel and hull where keel bolts passed through it, which also wasn't a good thing as eventually water got to it and fixing it was not fun. You may have done better if you made the area right under the mast solid fiberglass lamination and then to save money and weight, where you cut out all the other core material, gone with end grain balsa core.

 

[Ajay73]

Catalina hasn't been known to be one of the best built boats in the world and this is one reason why. Some manufactures of even earlier designs used to put plywood between the keel and hull where keel bolts passed through it, which also wasn't a good thing as eventually water got to it and fixing it was not fun. You may have done better if you made the area right under the mast solid fiberglass lamination and then to save money and weight, where you cut out all the other core material, gone with end grain balsa core.

Bill, thanks for your thoughts. Do you think I should use balsa to replace deck core where it's a 1/4 to 3/8" thick rather than the plywood as originally used? One thing about the damp plywood is that the top skin comes off pretty easy. Not saying it's delaminated but when damp there isn't much of a grip the plywood has to the top skin. I've recored balsa before and where it is just damp it sticks to top skin pretty well. At least that's what I recall. In the area where the plywood is 2.5" thick I wouldn't think I should use balsa there. I haven't gotten into the area under the mast yet. That'll be after I get the boat in the water and can get the mast down.