Date: Thu, 2 Sep 1999 01:50:50 -0700
Reply-To: Max/Joyce Wellhouse <maxjoyce@IPA.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Max/Joyce Wellhouse <maxjoyce@IPA.NET>
Subject: Re: Pop Top Sports Rack
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I think adding kevlar would be a stronger option to the reinforcement ofthe
glass top. Metal backing plates underneath would probably do, but depending
on the weight of the load on the Thules(including stress from side winds),
adding a metal plate underneat the same size as the fake gutter on top may
create a very undesirable stress riser where you have a very rigid
arear(metal) and a not so stiff fiberglass top. Constant flexing of the
more flexible material over time will crack the fiberglass where it meets
the metal. Having a somewhat larger underneath plate than the top plate
would theoretically spread the load out better. If you have an expensive
composite sea kayak that is relatively light weight, this may not be a
problem, but if you have an 80# plastic tandem sea yak, it may be another
story. Then there's the issue of loading that plywood and 2x4"s and lawn
timbers up there so you don't get the inside dirty. I would also roound the
corners of the bottom plate and make sure the plate conformed to any
curvature in the pop top.
Kevlar will add strength if epoxied properly in place, clamped and heated
for maximum bonding strength and if enough material is used. But kevlar
gives very little rigidity. An all kevlar canoe or kayak will eventually
flex itself to death and that's why foam cores or fiberglas or carbon fiber
are added( depends on how big your billfold is) to provide the proper
composite strength. Also, I doubt that VW tops are made with much more than
a woven roving or mat type cloth and these materials drink resin like a
sponge and likely only a chep polyester resin was used to hold it all
together so the adding of kevlar and epoxy reinforcement may be like trying
to make silk out of a sow's ear. But at least you tried!!
Dimwitted Moose and Flying Squirrel 90 GL 138k daily driver
From: Todd Thompson <ThZouave@AOL.COM>
To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
Date: Wednesday, September 01, 1999 8:33 PM
Subject: Re: Pop Top Sports Rack
>I have been thinking about the same thing lately. Here are my thoughts.
>1) fiberglass-- especially a drill hole is easily filled in and sanded
over,
>if your any good no one needs to know.
>2) there is also a type of rack that mounts to the top. they are made for
>camper shells. real cool-- also has a shovel/ax mount.
>3) mount steel backing plates on the inside for a metal to metal sandwich.
>
>Todd
>84 Westy
>washington DC
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