I built my deck with doorskins, so for hatch covers, I used 2 layers of doorskin material. Once the epoxy set up, the curve was there to stay. My brother built his from a single layer of 6mm Okoume. He couldn't get it to curve, and cut relief cuts about every 1/2" on the underside of the hatch. Clamping the thin ribs to both hatches was a PITA. For mine, I drove some finish nails through the innermost layer of doorskin into the center of the rib. The outer layer covered the nailhead. The nails worked well to keep everything aligned, but it still wasn't a fun job.

I read a post here about a week ago by someone who used strips of 1x spruce. That would be a great way to do it, as you wouldn't have to figure out how to keep the thin rib standing vertically while you're trying to clamp it to the hatch.

I just had a thought about flush hatches on a S&G kayak: Lay up a coat of fiberglass on the underside of the deck in the area the hatch will be. Lay this coat up the day before you will deck the kayak so that the epoxy has "dried" but is not completely cured. This way, the glass won't fall off when it's underneath the deck panel, AND, it will be flexible enough to take the curve of the deck. After you deck the boat, lay up another coat of cloth on the outside of the hatch area. Let both layers of fiberglass cure fully. Now you can cut out your hatch opening and use the cutout piece for the hatch cover. You could either build up a shelf inside the opening as Nick describes in his book, or you could cut a ring of plywood that is slightly larger than the opening on the outer circumference, and slightly smaller than the opening on the inside (so the hatch doesn't fall in) and glue it to the underside of the hatch opening. Once the glass on the outside of the deck is hardened, you can feather the edge of the glassed area into the rest of the deck.

Shawn

> The discussion of flush hatches has brought up a problem I had with making
> my last stitch and glue kayak (and I've been trying to mentally solve as I
> start my second).

> How do you make the hatch curve to match the deck?

> CLC suggests making small cross frames cut to match the deck curve -
> epoxied to the back of the hatch (clamp on individually). I was concerned
> about the hatch twisting so I made a jig - I cut slots in a length of wood
> (these would hold the cross frames vertical). I supported the hatch cover
> only along the edges and put the frames and the length of wood over top.
> Then I winched (by twisting loops of rope on either end) down on the
> length of wood - slowly bending the hatch too match the shape of the hatch
> cover. I was then able to glue it in place.

> Unfortunately, despite my best intentions the hatches still warped a
> little - forcing me to try and build up lips of silicone to fill edge
> gaps, plus by putting the weatherstripping on the deck rather than the
> hatch cover seemed to help (removing the lip for water to hit with a flush
> hatch has 2 benefits - 1- reduced splash, 2- waves tend to run over the
> hatch, and therefore don't force water past the seal).

> I plan on making new hatches for my boat as I build my wife a boat this
> year (I'll be trying flush hatches as well). Any better suggestions? Would
> I be better off to just clamp the cross frames individually? Or do I just
> live with some twist in the hatch and try to tighten the straps more?

> Mark