Re: [PSUBS-MAILIST] New Guy from down under needs help

[Jon Wallace <jonw@psubs.org>]

Alan James wrote:
>     There was a good article on why not to use fiberglass in the psubs
>     FAQ section but I couldn't find it.
Alan, is this the one?
Hey Guys, I worked in the fiberglass industry for some time as a plant 
foreman in a storm shelter manufacturing facility. As a general rule, 
one can expect the tinsel strength of standard composites to be 15 times 
that of concrete, and 3 times that of mild steel. In compression, the 
advantage is less. About 1:1 with mild steel, and 4-5:1 over concrete. 
This is by WEIGHT, not by thickness. The chance of making a mistake in 
fabricating here, for anyone not VERY good with these materials, is 
quite high. It is a hard media to work with even if you are experienced 
with it. Steel is SO much more forgiving. Also, composites that are 
damaged, even minor amounts, are virtually impossible to repair without 
leaving an uneven flex and compression area in the structure. The 
problem with that, I hope, is obvious. I for one think metals, at least 
for p-subs, is the cheapest and easiest way to go. Maintenance and 
monitoring are also much simpler. One needs ultrasound or MRI types of 
NDT rigs to inspect composites for integrity.
( Dewey Mason 08 Nov 2001 )

>     Getting the Stachiw book on acrylic is a must. I held off buying
>     it but am glad I did. 1000 pages
>     all about acrylic. If you join psubs the discount on the book that
>     you'll get pretty well pays for your membership.
It's better than that.  You get the book and your membership for less 
than the retail price of the book.  Non-member book price is $195.  
Membership plus the member cost of the book is only $175, total.



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