: You can make ultrathin mirrors from several 1/4 : inch thick plate glass sheets glued with silicone : or other suitable aquarium cements. I have been : wanting to build an ultrathin mirror also and have : been calling around the local glass suppliers to : get the lowest price on 1/2" thick sheets. I found : that you can get them for around $20 or more. : I have also heard of people salvaging table top : glass and cutting it with a jig saw blade and grit, : sort of like cutting holes with a copper tube where : slots in the tube guide standard carbide grit to cut : the glass.

: : : In my location, mirror blanks are very thin on the ground. I know a glass merchant who can cheaply cut disks from 10mm glass. My question is: Would it be OK to glue a number of these disks together to make up a required thickness provided a reliable adhesive was employed. : : Many people have tried and all have basically failed. One of the biggest problems is the expansion of the glass as the temperature changes destroying the figure of the reflective surface. May I recommend that you give Willmann-Bell a search on the NET. They are probably the : : best place to get astronomical books and also they have some nice kits and pyrex (better than glass) for reflectors. If you want to get into refractors, Newport Glass Works (Newport, Ca.) has some nice refractor kits. If you want to do a mirror with the glass that you have, : : I would suggest that you do a small mirror first and then try to get through the problems of doing a very thin mirror with the next project. Use the first mirror as a guider/finder for the main scope. Have Fun and Keep Looking Up! Bob May