Bulkhead replcement?

[Bilbo]

I just bought a 1987 C22 in September and the PO didn't repair the leaks in the upper shroud deck fittings. Now the main bulkhead on the port side needs replacing because of delamination. (I also want to add a storage cupboard area over the sink while providing some measure of privacy for the head).It doesn't appear to be that difficult because aside from the upper shroud bolts, the rest is just screwed into the fiberglass sink area with wood screws.My question is, should the paneling/bulkheads be marine grade plywood, or is jsut common 1/2" acceptable?Thanks~Bilbo

 

[Dick of Sylvan]

Exterior Grade

Bilbo: If it were mine, I'd use exterior grade plywood, since marine grade is harder to find and more expensive. I believe it may have an extra ply, but I don't think you need extra strength from that direction for your bulkhead. And exterior grade should have a good enough glue for interior work providing you keep the chain plates sealed. Dick

 

[Bilbo]

Bulkheads

Thanks for the response. I will check into the difference of Marine vs. Exterior. I would like to go with the safest most durable material. Two issues that I have in that part/function of the boat.1)I am trying to figure out why 4 strong bolts from the upper shroud chainplates for strength but smaller wood screws around to fasten the bulkhead to the interior. Maybe it is strong enough that way.2)I can't be sure that the chainplates won't leak again. The only way that I discovered the leak(s) was by going around with a bucket and dumping water on areas where I suspected leaks. chainplates turned up with water as well as a few other places so far. Anchor locker and the little V berth skylight.

 

[Dick of Sylvan]

Bulkhead Screws/Bolts

Bilbo: I agree with your concern re/small screws between wood bulkhead and interior fiberglass. I've had to upgrade mine, twice, mostly I think from vibration while trailering. Last time I used bolts with a backing nut used in household wallboard construction. Dick

 

[Ken]

Bulkhead screws

Isn't that something, 5/16" bolts holding the chainplates onto the bulkhead and #8 screws holding the bulkhead to the boat. We were tacking one day when the Admiral said did you see that? The Bulkhead raised a couple of inches. Finding it hard to believe we tacked again, both sides were loose. To solve the problem I cut matching SS flatbar 1/16" thick and a cross piece at the bottom. I used 1/4" bolts at the bottom. This tied the upper chain plate to the boat. It made a huge difference in the boat.

 

[Clark]

Marine vs Eterior

Bilbo, to address the Exterior vs Marine thing; Marine ply has more plies so it its a little stronger, a little better grade of glue and no voids. Exterior is allowed to have voids which is not a good thing. You could probably save $50 using exterior but that is up to you. The way bulheads work on our boats is that all that stress from the chain plates is (supposed to be) exerted in a straight-pull in line with the bulkhead. They're very strong in that direction. Also, the bulkheads are held in place by tabbing and channels in the deck molds to prevent shifting under load. As for the chainplates leaking, just do a good job with the sealing around the tab coming through the deck, seal all the edges and thru-holes in the new bulkhead with epoxy and inspect the area periodically.

 

[Clark]

Oh Man . . Sorry for the Spelling

Is there a way to edit posts ??

 

[Bayard Gross]

C-22 Tech Manual

That repair is covered in the Catalina 22 National Sailing Association Technical Manual in section 4 on rigging.I beleive you must join the Association to get the manual, but you should do that anyway.Use the link below to the Catalina 22 National Sailing Association site.

 

[Bilbo]

Bulkheads

Thanks everyone for the great responses. I went to the boat (in storage) yesterday and tried moving the stbd bulkhead fore and aft and it's not fastened very well at the base with the rot down there so both sides are definately getting a change. I found a small scrap piece of the plywood in front of the V berth & behind a board that I varnished up there in the bow. IT's about 7 plys. 5 main underlayments and a very thin verneer layer of teak (I think) both sides.So this wood is generally used in areas such as the settee sides and some vertical trim pieces around the boat.Been thinking about it for some time anyway and we will also be joining the C22 Assoc. Thanks Bayard.I called a couple of Lumber yards and I think that I can order some marine grade ply from a local one. One tried to sell me the treaed plywood. -Ok for utility sheds but I am trying for a decent looking interior and not just utilitarian. -if I wanted it to "just work", I could probably use a sheet of 1/4" thick aluminum or some other non-wood item for strength.Thanks all, ~Bilbo