Normally when grinding the goal is to take a rough surface and make it smooth, but when making a ground glass you’re taking an incredibly smooth and flat surface and making it rough, so the normal process of working up from lower grits probably doesn’t apply.
depends how rough you want to make it...Originally Posted by teathomas
you can apply only F600.
In the post #3 when showing the grinding that's what I mentioned: "apply F600 only will work."
it´s about the time spent. From glass smoothness, F400 to F600 is faster than just F600. I didn't chronometer it, though, subjective time estimation?
grinding from rough to smooth can be done with final finer grit too, but will take loooong :-)
from research on this topic, there is a chemical that etches the glass. but is not for public use ???? I do not recall the name of this chemical. this is the best !!
I have done a working study, practically I used a white translucent plexiglass which worked [a bit too thick] but it worked and was unbreakable! after 19 years I want to change it.
On the 9x12 I used a plastic stick-on Imitation frost glass [it works] - also matt varnish && frost spray-paint it works [SO & SO] Q&&D style [Omega line] last minute no other way out...
well - the glass can not be to smooth [fine]- there has to be a certain angle etched [cut] on the glass to get an focused image that one can see with detail!! Used a special stone that to worked up to some point ... but not the same as the etched glass.
see if I have time to post photos ....
Lots of strips of frosted tape (like Scotch "Magic" tape), stuck side by side to glass...will also work in a pinch!
John.
do you have knowledge of a old type of focusing glass that used an X scratched on the focusing glass -- some years ago on a 13x18 in. the glass was just fuzzy with an X somewhere in the middle it worked, BUT!!
asking just for history...
....frosted tape (like Scotch "Magic" tape) great!!!
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