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darryl
09-24-2006, 01:57 AM
I've wondered about this many times, but never experimented with it. Has anybody ever tried making a see-through panel using clear casting resin and glass cloth? I've imagined that if the resin and the glass had the same index of refraction, the glass would essentially disappear in the resin.

To do the experiment, I woud use two pieces of glass, mold release, etc. Coat one piece of glass with mold release, then a layer of resin only- wait for it to tack, then fully wet with resin again, then lay the cloth in the resin. After it has soaked it's way down, add more resin, more cloth. For the sake of an experiment, maybe try about 4 or 5 cloth layers. Apply resin again, wait for it to tack, then apply the final resin and lay the second piece of glass down onto it.

Ignoring the air bubbles that might have remained, would the panel be see-through? In other words, could I read words on paper through it?

I'm just curious- at one time I wanted to make a canoe with some clear areas on the bottom. I don't think I'll be doing that now, but the question has never been answered. Anybody know about this?

Evan
09-24-2006, 02:10 AM
You will get the same result as the corrugated fiberglass greenhouse panels. Translucent but not transparent.

The index of refraction has to be very close to the same. For an example of that try immersing some pyrex glass in corn oil. Then try finding it. A small test tube works well. Then try regular soda lime glass.

Trouble with the fiberglass and resin is that the resin has an index of about 1.5 but the glass can be from 1.5 to 1.9 depending on type.

thistle
09-24-2006, 04:48 AM
You can get a very good finish on a piece of wood if you use special epoxyand hardener developed for clear coating ,
how that translates in to a clear panel i dont know.
As far as polyester resin,think the green house "filon" or whatever its also called ,is as good as it gets.
Apanel with fair qualities as far as vision is concerned on a canoe would be pretty thin and unacceptably weak.
better would be to figure out how you could incorparte a polycarbonate like lexan into the canoes bottom.

rantbot
09-24-2006, 02:02 PM
Sounds like you want an epoxy.

http://www.hisglassworks.com/files/refraction.pdf#search=%22epoxy%20clear%20refractio n%22

Reading print through it may not be a terribly tough test. Refraction would scramble the images of more distant objects. Consider glass with a wavy surface, with a wavelength in the 1/2" range. Very close objects are clearly visible in detail, but everything more than a foot or so away is a blur. This used to be stylish stuff to use in bathroom windows, for that very reason.