[MM33]

Just a question why I would nail the template on top of one another? Is MDF thin so you need 2 nailed together to form a template?
Also, Do I put anything down when I do the Gelcoat layer, or is it just Gelcoat mixed with MEKP. I got a little confused with the sentence "then 2 layers of mat for what is called the skin coat" what do I lay down the 2 layers
of mat with??

Step 1 - I would put the hatch you have down on a piece of MDF and scribe twice on two peices. cut the inner section out of both of them so you have 2 outer templates. screw, nail or staple them together one on top of the other.

Step 2 - get some sculpy putty and raduis the hard edge on the bottom like the other hatch.

Step 3 - wax the mold

Step 4 - get a pint of gelcoat from any marine store. roll the gelcoat down mixed with MEKP. then 2 layers of mat for what is called the skin coat, it is important that you get all the air out of these coats.

Step 5 - Once that kicks, 2 layers of 1708 biaxial. Depending on whether or not the hatch is cored, then you would core it with some 3/4 ply would in the middle.

Step 6 - Then a couple more layers of 1708 and you are done.