Re: [bolger] Re: Plywood Again??? Forget Marine Ply!!!
> Glassing on the outside adds durability but little strength unless thick and heavy.Strength. There are different types. Bending, compression, shear,
torsional and tensile.
The strength issue with boat hulls is complex and a mix of all these,
but the largest component of strength in hulls is the shell effect
which comes mostly from tensile (and compressive) strength.
Fiberglass has awesome tensile strength properties and good
compressive strength too.
Pull a single fiber strand out of fiberglass cloth and try to break it
with your bare hands to see.
Fiberglass adds much more than just durability, it adds tremendously
to the tensile strength of plywood.
I agree that large ply voids degrade shear, bending and torsional
strength, but I don't see that those are the most important types of
strength with fiberglassed plywood boats.
- That's exactly what I did. I don't know how thick their skins are; but If I
were in a position to order a boat build that way I'd insist on a filling of
the slots at leats with more foam.
I really don't claim or want to argue my point beyond the fact that I looked
at it in a very amateurish way; but decided I didn't trust this method; or
voids and gaps between skin sheets in a composite.
Now no matter how wrong I might be; I'm never going to be particular happy
in a boat that has this issue; so I avoid it.
On Jan 8, 2008 11:31 PM, Stefan Probst <firstname.lastname@example.org>
> --- "Hajo Smulders" <hajosmulders@...> wrote:[Non-text portions of this message have been removed]
> > Slots were probably up to an half an inch wide in a 2 inch piece
> > of foam at the 'open side' of the curve. These were gaps; not voids.
> Something like on
> under the headline "Wide foam sheet planking"?
> Seems to be ok there.