Re: Resin over varnish

Posted by Mark Camp on Jul 20, 2004

thanks Kyle, that answers my question about "why" epoxy over varnish doesn't work.

Warning: Long boring 'Ask Dr. Science' type post follows.

I had actually just figured it out on my own, after a frustrating search of the web. While staring at the amazing results of the "spit test" last night in the workshop. It occurred to me that, since the glass cloth disappears when impregnated with epoxy or water, the three must have the same refractive index! (My high school science teacher, who gave me that F in Physics, would be so proud!) If sanding into the glass and then varnishing looks bad, which I have read many times on this board, then varnish must not have this same index. It suddenly hit me. If you epoxy over varnish, you will have a refracting layer of varnish sandwiched between two layers of something less (or more) refractive. While this forum's two amateur astonomers could probably exploit this fact to fabricate a lens--for a built-in kayak solar oven?--it would in general look like crap.

In Response to: Re: Resin over varnish by Kyle T on Jul 20, 2004


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