: Gentlemen, I am sorry to keep dragging you back here but I am not
: getting this hatch seal thing. I have already read Kurt's and
: One Ocean Kayak's sites which are excellent and I re-read them
: again and they make perfect sense to me. What's not to
: understand about peel-and-stick weather stripping with a tapered
: face for better sealing. I understand it - - until I read this
: post made by someone a few weeks ago - -

: "Perfect material to form the channel. It's a silicone rubber
: strip that is self adhesive on one side. I ordered the exact
: size I wanted for the channel from McMaster-Carr. The self
: adhesive pulled right off the packing tape I used to protect the
: inside of my hatch and then the silicone rubber stretches and
: releases from the channel leaving a perfect trench for your
: gasket. It is also dense enough that it won't deform when you
: press down on it when packing glass around and on top of
: it"

: This post raises several questions. The first questions are - it
: sounds like the silicone strip is being used as a form to lay up
: glass for it to fit into? How is this possible, there would be
: no place for the silicone to expand to when compressed to form a
: seal. How could it compress within a rigid glass structure ?

: And to make matters even more confusing I have another post where
: someone is saying how difficult it is to find two different
: sizes of stripping that will fit together?? Why would one need
: two different sizes?? Unfortunately, the more I read the more
: confuseder I get:(((
:

Most builders that mold a hatch lip using a thin foam when molding the lip, remove it, and later put in a thicker foam for actual use. The thicker foam will be higher than the lip, but compress into the lip when the hatch is secured. For instance, if you wanted a 1/2" wide channel, you might use foam that is 1/2" wide and 3/8" thick when molding, scrape it out, and use a 1/2" wide and 5/8" thick to make a tight seal.

The thinner foam used for molding is normally layed down on the inside of the deck (with a plastic or packing tape layer on the deck as a mold release) and then fiberglass layed on top of it.

It sounds like the silicon is only being used when molding the channel that will later hold the foam.

I usually have no trouble finding the sizes of foam I want at Home Depot.

John