Re: Vacuum Drying

From: Chris Rowe (
Date: Tue Sep 15 1998 - 14:22:03 PDT

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From: "Chris Rowe" <>
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Date: Tue, 15 Sep 1998 14:22:03 -0700
In-Reply-To: "Brad James" <> "Vacuum Drying" (Sep 15, 12:12pm)
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Subject: Re: Vacuum Drying
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Brad, vacuum drying sounds like a cool plan. But getting the board down to 1/3
of an atmosphere sounds dangerous. From the little board-building experience I
have with styrofoam core boards like you're talking about, I can offer a little

        A "full pull" of one atmosphere will crush a board down to 3/4 its
        original size, caving in the bottom and flat parts of the deck.

        Getting to 1/3 atmosphere is right at the edge where the styrofoam
        take it alone, so the skin takes a lot of the load from the vacuum, and
        at that point you are risking damage by crushing and buckling.

Because the concave bottom shape went out of fashion years ago, I would suggest
trying to never go below 1/2 of an atmosphere. I'll never take one of mine
below 2/3 if I can help it. Maybe use a combo of heat and vacuum? Trust me,
it really blows (pardon the un-pun) to leave a board under vacuum, go for
pizza, then return two hours later to find a broken, shrivelled remnant of what
used to be a 1500-dollar slalom board.

Of course, all this only applies if you are vacuum bagging it, or sucking
directly from the nozzle of the board. If you put the thing in a
depressurization chamber or autoclave, then pressure won't destroy the board no
matter how high or low it gets because it will equalize inside and out. I was
just guessing you don't have a chamber because otherwise it wouldn't matter
what kind of vent plug the board has.

Rock on,

Chris Rowe
Silicon Graphics, ASD Product Design 

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