On Mon, 06 Jan 2003 19:28:51 +0100 Carsten Standfuss writes:
>
>And plywood is not really pressuretight.. I use it to make the two
>mold frames to blow a acrylic dome - and the pressure lost in the
>longitudinal direction of the wood..
Was the plywood being used as a mold; that is, was the acrylic
being formed against the plywood?
In the plans for the Markham sub, making a blown dome is
to be done by placing the frame around the bottom edge of the
acrylic sheet and forcing air into the underside of the acrylic.
Apparently, getting the flat part is done by pressing a piece of
wood against the soft plastic. But there's no pressure on the
bubble canopy of the Markham boat.
>Why plywood ?
My project is a full-size working replica of Simon Lake's Argonaut
Junior. The original boat was made of two layers of pine planks.
My version would be three layers of 12mm or 16 mm plywood
under 12 mm of fiberglass. This thing would not be put in water
that would be much over my head. If the bottom is more than 10
or 12 feet down, I'm not going in the water.
Mike H.
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It is possible to make a Ship or Boate that may goe underwater
unto the bottom, and so to come up againe at your pleasure ...
-
William Bourne, 1576
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