Mirror maker

[BEN Driss 0]

Hi floks

I'm fine grinding and polishing an 8" mirror. I used permanent pen to do a pen test. But I did not know that the pencil is soaked with diamond powder. I had serious scratches. I managed to mitigate them, but they still persist. I am at 12 micrometers. Someone has an idea how to solve this problem.

 

 

[jean dijon 1 761]

Hi BEN

if you have scratches you have to go back to coarcer grain otherwise it will take a very long time to suppress them. What is your pen test? I don't think you need it at last with small grain.

jean 

http://www.jeandijon.com/index.htm

[BEN Driss 0]

Thank you Jean. That's what I did. But, there are still some left. I am at 12 microns. I wonder if I go to 5, then 3.5, 3, 2.5, 1, and 0.5 micron, in the long run these scratches could disappear. What do you think?

[jean dijon 1 761]

Hi Ben

 

if you go to smaller grain you will never suppress your scratches. So first go to coarser grain typically 20 or 25µm when the scratches will be supressed then go back to the 12µm and finer

i am  shure you don't need to go to grain smaller than 5µm you jusy increses the risk to scratch without benefit for polishing. So go to larger grain to suppress your scrates then go down to  12 µm 

for a 200mm the number of wets are typically

_6 for 12 µm

_4 for 10µm

_4 for 8µm

if you have no 10µm increases the number of wets with 12µm anf finish with the 5 µm at least 6 wets

good work

 

jean