Builders' Forum Archives
Posted by Mike D on Oct 16, 2005
Yes as the plywood gets thinner it does get lighter - but....
A big factor in how stiff a composite panel is how far apart the skins are. Thicker plywood equals stiffer composite panels and so stiffer boats. However the reduction in panel stiffness is geometricly proportined to the reduction in thickness - the decrease in stiffnes is more then the decrease in thickness. in other words going from 4 MM to 3 MM plywood lowers the weight of the plywood by 25%, but reduces the stiffness by significantly more.
Since the plywood is only part of the weight of the complete panel (the glass and epoxy will be the same)the 25% plywood weight does not mean the panels are 25% lighter.
Thinner plywood makes for lighter boats but at the cost of boat stiffness and stiffness is one big advantage S&G has over tupperware.
Happy building, MD
In Response to: Re: fiberglass thoughts by Dave on Oct 15, 2005