Parts NLA

[Duncan Thomson]

At 09:15 10/05/2002, Fisher, Scott wrote:
>David Ullrich writes, regarding the missing radiator duct/shielding on his
>CGT:
>
> > I can't really make one, I don't have anything to use as
> > a template.
>
>Not really a good idea to leave the carboard in
>place after initial tests.  An intermediate step would be to use some of the
>stuff they used to make the yellow Beetle bodyshell on last night's "Panic
>Mechanics" episode (all right, the dirty secret is out!!!) -- same
>construction as corrugated cardboard, but made out of some kind of plastic
>so it's water-resistant.

I saw this done on an '84 UrQ... They had used two layers of a plastic real
estate sign, glued together and cut to fit... I assume you guys have these
same signs in the U.S....
It was white, which is what gave away the material... I think I would paint
mine black if I was going this route, even for a temporary job...

>The Right Thing to do would be to make the new shielding/ducting out of thin
>aluminum sheet (which is likewise easy to cut and to bend), using the
>cardboard as the template, and drill out holes for the mounting screws
>rather than duct-taping it into place.  I have to do that one day...

I also intend to get around to this some day...!!

Duncan

p.s.
As a side note, another use I have seen for these signs is as a heat
exchanger... I saw it at university, the signs consist of two thin sheets
of plastic attached by parallel reinforcing ribs, the entire structure is
3-4 mm thick...
for the heat exchanger they had sandwiched these layers together, orienting
the ribs at right angles on alternating layers. They built up a composite
about 100mm thick. Pipes carrying the fluids to be cooled/heated were then
run into the composite were sealed to this exchanger using silicone at 90
degrees to each other... this would run the fluids through alternating
layers (parallel to flow) and allowing heat transfer...

the plastic is not the best heat conductor, but it is thin, and the contact
area of this arrangement is massive... obviously only suitable for
temperatures near ambient, but was being used for liquid cooling, so it can
be made airtight...

getting way off topic here, but it's something I found fascinating...

anyway, enough rambling...