Hey Guys,
I was in the same predicament once. I had to fabricate the vent plug and some footstrap
plugs for a sailboard.
You can make a mechanical (active) vent plug by getting a nylon plastic bolt from BBC hardware
or the like. I’ve even taken a Nylon hex bolt and milled it into a ‘cheese head’ screw by putting
the bolt into a drill and taking a file to it.
Then coat the bolt with automotive paste wax, using a couple of coats.
I drilled a hole into the board and set the plastic bolt in the center of the hole. I put a bunch of
masking tape to cover the hole AND bolt. The tape acts to hold the bolt, and to keep epoxy from
leaking all over the place. Tape was flush with the deck.
Then,
Peel the tape WITH the bolt stuck to it. I pour a mixture of epoxy and microballoons (thick mixture,
pretty gluggy) into the hole, not quite full to allow room for the bolt without overflow.
Carefully place the tape/bolt assembly back into place. Seal tape well.
Once everything looks right, FLIP the board upside-down and let the mixture kick off.
After the epoxy is fully reacted, just unscrew the coated bolt and there you have it.
*If you forget to wax the bolt, you will be hating life…
Look at the pic of the vent bolt below for reference. Scroll all the way down to part R62-5152
on this website (not affiliated):
http://www.fiberglasssupply.com/Product_Catalog/SurfSailcom/surfsailcom.html
Note the O-ring which is an essential part of the device. The bolt head (actually screw head)
is “cheese head” style, not a hex bolt… …you can even put a groove in the bolt to let the
air escape, just be sure your Ring-piece still seals flat! ha hah.
You can fab a ‘Gortex’ passive vent as well which should be about as straight-forward.