... minimize TDE around the hole. When cold pressing, the pitch would flow up into the hole making figuring impossible. You should try a holy polishing tool....
Actually, there is a form of low temperature bonding of glass using a sodium silicate solution. I have never tried it, but you never know... .. . Richard ... ...
... From: RON WHITE First off let's keep one thing very clear I am not recommending the methods I used to fabricate these blanks, This is an experiment and I...
If you made the posts this way, there would be no "give" in the structure, and it would be sensitive to thermal stress the way my blanks are. ... From: Joe To:...
A 1" thick front surface shouldn't have any printthrough otherwise you are realy doing something wrong for pressure when polishing/figuring. I wouldn't worry...
Interesting blank designs. I am glad to see people are experimenting. Print through can occur however from other factors than just those resulting from...
Thanks for the explanation. Obviously you have much experience with unconventional mirror design, silicon carbide mirrors, wow! Maybe it is why i never see...
If i remember correctly sodium silicate is highly hygroscopic, maybe restricted for desert use only.... but again, there is also frit bounding, that can fuse...
... again but ... maintain the ... James, Boy, this is frustrating. I think I worked backwards again. I've lost whatever progress I made with the small tool on...
... After studying the Ronchigrams for the last two runs I don't see that much difference between them. Actually, I think there is slightly less curvature ...
... wrote: Hi James, Thanks for the quick response-I got booted offline by my daughter so she could get information for finishing a project for school. After...
... From: RON WHITE ... Hi Ron, well you did say, and i quote: "My 14" has a 1" face plate with 1/2" ribs and back plate. it is a very accurate spherical shape...
Jean I still haven't done the "cold" test you recomended. I'm thinking that the front and back plate will normalize to each other and not cause any problems. -...
Jean: I have followed what you are accomplishing with interest, and would like to know your thoughts on the best way to mount a structure such as you have...
... using a sodium silicate solution. I have never tried it, but you never know... ... This sounds a lot like the refractory cements used to assemble and seal...
... a sodium silicate solution. I have never tried it, but you never know... Is this perhaps the same material known as "water-glas", a water based solution...
Yes water glass is the same stuff. If I remember correctly this has been tried before and the blank failed. I cannot remember the details but it was related to...
Jean, Did you "slump" fuse the 26" mirror for sagitta, or do you grind the top surface, because you used a double layer of plywood for backup and unless it is...
Hi, yes the faceplate is slumped to radius and the backplate is flat to minimize mounting difficulties. So the frontplate is a meniscus of uniform thickness. ...
Jean, Won't the simple mounting procedure causes the front surface to deform like a regular thin mirror? Or have you tested the mirror at various angles and...
Hi Don, Yes i have tested them in different orientations, like in actual use in telescopes. In fact i have had one in constant use for the last 4 years in our...
Jean-Guy, You seem very proficient at fusing blanks particularly the hair brush style, have you ever considered going the next step and casting some? Best...
Hi, Can it be that you refer to that old S&T article of the sixties where an Australian amateur made this kind of mirrors with glass plates and Al rods ? He...
... 50% tool. ... consider ... of ... discouraging for ... next. ... if I can ... Hello James, I've performed some work on the glass but inadvertantly used an ...
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