Step 1/2. Put a 1/8"X1/8" (or so) rib running around the underside of the hatch cover, just in from the edge so that it rests on the center of the hatch lip. When you remove the hatch after the silicone is dry, it would have a groove running around the middle of it that the rib would fit into. Water would have to do a U-turn to get into your hatch.

To build the hatch perfectly flush, though, you would have to recess the lip a bit to compensate for the rib.

Another idea just struck me: You could router a small groove in the underside of the hatch! Then when it presses down on the silicone, it creates a little vertical rib that would mate with the groove. Or you could router the groove in the recess and apply the silicone to the hatch... now where's that asprin--I'm getting a headache...

Just a thought (and a half.)

Dean

> 1. Spread a little vasaline to the bottom of the hatch.

> 2. Use a caulk gun to apply silicone to the hatch lip.

> 3. Spread the silicone out over the entire hatch lip as smooth as possible
> with a putty knife.

> 4. Take Saran wrap and apply it over the open hole covering the entire
> area.

> 5. Push the hatch down into the Saran Wrap covered hole, wrap the Saran
> Wrap edges sticking out up around the top of the hatch and tape the hatch
> in place.

> 6. The next day peal the Saran Wrap edges back off the hatch and it pops
> right out. The Wrap peals off the Silicone just as easy and you get a real
> shinny tight seal, just trim the edges with a razor knife and your all
> set.

> JUST DON'T FORGET THE PLASTIC WRAP!!!!!