At 07:57 PM 8/19/2010, neil n wrote:
>For anyone else interested, here's an example of a similar type of
>foam to what I think David refers to. Seems cutting the billets can be
>done, but this stuff is 1/2 in. x 4 ft. x 6 ft sheet.........
>
>for  $68.72     ;)
>
>http://www.marinefoam.com/closedcellacousticalfoam.html?page_type=flotation-foams

That's a fancy-grade flexible sheet for lining hulls and such.  The
flotation qualities are incidental except to people (and they exist)
who want an unsinkable boat. $70 for a cubic foot.

http://www.buoyancyfoam.com/  has the Dow stuff.  A 7x20x48 billet is
~$85 for almost four cubic feet.  But you need to use a hot wire or a
hand saw or big bandsaw to get thin slices out of it.  Not really
practical; I didn't mean it seriously.

But to say it better about the bead-board -- no open-cell or sintered
foam will resist liquids unless they have a continuous skin -- and
then only so long as the skin is intact.

Yours,
David