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Re: Laminating Plate Glass.

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Posted by Robert May on June 15, 1999 19:19:02 UTC

Epoxying the glass together will not work as just in the normal usage of the glass it will delaminate. The welding I am talking about is using pieces to produce ribs to join a front to a back piece. Welding is the right word and the process is just like making glassware from pieces of glass like the glassblowers use. Epoxying has been tried and the temp changes just kill off the glass. Better that you break the glass up and put it in a furnace and melt it into a thicker piece and then gradually decrease the temp to allow the stress of the glass to be relieved (annealing the glass). Double thickness glass is otherwise not of much use except as a window to hang a secondary on (you need to make it flat within a 1/4 wave for this to work as plate isn't very flat optically) and other things like that. For an 8" mirror, you might go and get some 1/2" thick glass for them to do an 8" although 1" would be a lot better if it's a first mirror. Where are you going to get the grits from?

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