: I have made magnetic flush hatches for my CH16, and I have read in past posts
: that if you do not put a layer of fibreglass over the magnets they will
: rust.
: My idea to stop this, is to put a layer of glass over the magnets but i need
: the layer to be as thin as possible so I thought vacumn bagging would
: achieve this

Try the vacumn bagging if you're looking for the experience, but... I just finished building up a retention setup that has about 9 oz worth of fabric plus resin between the magnets. The lid still snaps down hard enough that folks comment about it. I've got 8 - 9 pair on my large hatches, 4 pair on my day hatch.

jrs