Telescope Project - Part 3

Here's how my tile tool and mirror blank look after hogging out and some other work with 80, 120, 180 and 320 grits:

Telescope Project - part 2

I now have the mirror kit (about which more later) but I thought I would post first about the plaster of paris tile tool I made for the mirror.

The design for this comes straight out of the Stellafane website. I made a disc of plaster based on the mirror blank and after setting, it sat in my airing cupboard for a week. I have sealed it with many layers of Thompson's Water Seal on one side and a layer of epoxy resin around it.

The tile fragments are pieces of bathroom tile left over from our house extension. They are ceramic tiles with a glaze pattern printed to look like marble. I took one tile offcut and smashed it in a plastic bag with a hammer. Then I glued the fragments in a random pattern on the face of the plaster tool with Araldite epoxy.

The mirror kit I bought from Galvoptics is a bit strange. Not only are the two glass discs not identical (one, presumably the tool, is about a quarter of an inch smaller in diameter) but the abrasives supplied start at 180 grit, not the 80 or 120 I would have expected. Because of this I have had to order some more grits from Beacon Hill and as of today (Good Friday 2006) I have yet to receive them, so this Easter weekend is wasted as far as the mirror project is concerned, a real pain in the arse.

Still, this is a major leap forward for me. I only hope that the grinding (if and when it ever happens) goes OK.