: 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?

Hello Robert, I am re-thinking this telescope project. It all started with my two grandsons and a library book. Neale E. Howard's "Standard Handbook for Telescope Making". It states that the cost will be $100.00 for a modest insturment and $150.00 for a more ambitious one. From what I have found searching the web you can not buy a set of blanks for that! Cutting costs was the reason for asking about the use of the 1/4" plate that I had. If I was sure that they would complete the project, I'd come up with the money and go all out. I can relate to there desire for a nice scope. It reminds me of myself around 50 years ago. I spent all my paper route savings and order a "telescope kit" from a Popular science magazine. I was crushed when I received a box full of glass and a grinding compounds. With no one to turn to for help and not understanding the instructions I figured I had been had. (Sure would have been nice to have had the net in those day!) Needless to say, that scope never even got started, let alone finished. There interest has re-kindled mine. I plan on building a scope with them but need a little more time to educate myself and get the materials together. I'm retired GI so I need time to do some scrounging around the DRMO and etc. Thanks for the info so far and I'm more than sure I will be needing a lot more in the future. Dick

• Re: Laminating plate glass. - bobmay - June 17, 1999 - 03:50 UTC