If cost is a factor too, as it is with me, you may find that minicell is a lot more expensive than 4 mm plywood. If cutting holes in your deck is the issue, there are some good options.

Here is an idea that I found on this BBS some time ago. I wish I could reference the author but I can't remember. I am going to use this on my rear bulkhead for the arctic tern I am working on now.

It involves cutting two matching bulkhead blanks. Install one by trimming to fit and filliting and glassing the edges for a watertight seal. After that is all set up you cut out the middle of the bulkhead with a jigsaw so that there is only about an inch "rim" all the way around the inside of your boat. Now match up your second bulkhead blank (trimed to fit) with the rim you installed. Drill holes through both the bulkhead/hatch cover and the rim for bolts to come through from the back. Use wingnuts to bolt on this bulkhead hatch. To acheive a watertight seal use a gasket or weatherstriping around your rim so that when you tighten down your wingnuts on the bolts it clamps it down tight to the gasket.

This will not be any easier to construct than the normal approach to bulkheads and hatches but gives me a clean deck and a big advantage in loading gear since this makes my hatch opening a lot larger.

Keep in mind that this is just theory now as I have not tried this yet. Good luck.

Mike

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: I am finishing my Coho, and need to make a bulkhead decision. I intend to use
: screw in deck plates in bow & stern bulkheads for my boat, and skip
: cutting hatches in the deck. Since my primary use is day paddling, I'd
: rather not have the additional holes in the boat.

: Installing foam bulkheads seems easier, lighter, & quicker than plywood,
: however I am concerned over their watertightness. Are the foam bulkheads
: watertight if well caulked?

: Also - has anyone tried to install deck plates in minicel using 5200?