The sandwich glass configuration have a behavior a bit different then a classic round disk. Here are some recommendations that will help you in your project
Very important to clean the glass well when change of abrasifs. You should use a tooth brush and a shower head.
You can use masking tape to cover the edge of the blank to reduce the cleaning operation
If you use a polishing machine, reduce the RPM when using lime glass and BVC, up to 50% at finer gritt & polishing
If you heat up the blank, back & front faces must be heated at the same time, to reduce stress on segments
Vacuum coating done cold or heating both side of blank simultaneously. If some doubt please contack us
When working Tool On Top (TOT) be sure to properly hold the mirror. The mirror could be sitting on 9 - 18 points of Plasticine, or cast a plaster seat of the mirror back. Then place pieces of rug to simulate a mirror cell
Avoid tool/mirror sticking, put aboundance of abrasifs.
BVC ideal polishing agent: cerox 1670
When using any polishing agent, Break the possible grain agglomerate with a hand mixer, to avoid sleeks.
Apply the PPP mode: Passion, Precision, Perseverance
Avoid any impact on the blank. This a delicate piece of glass
In a mirror cell, you can hold the blank by the backface. Avoid glass pinching
When you send the blank in a box, Styrofoam or bubble plastic sheet., to protect the glass