: I have read some suggestions to use MacTac (plastic shelving paper) as the
: mold release when epoxying a hatch lip. Is this all I use ? Do I need wax
: or mold release as well?

mac tac has lots & lots of different types, & so is "Avery", "3M" & zillion
others.

what you need to check is wether it can be removed from a dried epoxy surface
after being on it for few days, because some of these materials are designed
not to come off, no matter what.
another issue is to see how much glue the material leaves behind when
removed.
& the important issue is to check if the pvc doesn't adhere to epoxy.
I'm not sure if epocy adhere's to pvc, but most of these pvc sheets are
covered with a transparent material that is designed to hold the ink
that is printed on it.

: Also, I'm using flush hatch covers. Once the sealing foam is in place how far
: does the hatch cover sit above the deck? Has anyone tried to recess the
: hatch covers while epoxying ?

yes!

that's the way most of us are doing it.

we calculate/measure the gap needed for the sealant, so the hatch cover
is flushed with the deck.

check this link:

http://homepages.go.com/~fl_pelican/home.htm

it will give you some idea.

Erez