Ian I am living in Greece and ordering heavy packets from overseas is unfortunatelly out of the question. I can't find under 220 abrasives from sandblasting supplies locally so I may order only 400, 800 and 1000-1200 from some european supplier, 80, 120 220 is easy to find locally. I also find attractive the HCF lap as describeed in ATM 1 book! Beekeeping is very popular here and a sheet of HCF costs less than 1€. You can even make yourself HCF sheets with a homemade press! HCF seems easy to make, clean and fuss free, totally unlike the nasty messy pitch. For initial polishing seems HCF is the definite way to go! BTW what is the coarser abrasive to use before polishing?
Aluminum oxide is used between silicon carbide and polishing.
Think of silicon carbide as hammering a sharp spike in to crack and quickly remove chunks of glass during hogging. It leaves lots of subsurface damage that can be seen in the sun. You use finer sizes as you reach your curve so that you can remove the deepest shattered areas faster and leave less of them. Once you are close, 320 or 500, you can switch to 25 micrometer aluminum oxide. It kind of shaves the class, removing most of the remaining glass, and making the glass look clear but not that shiny.
Aluminum oxide removes subsurface cracks but still leaves a jagged surface. Polishing rounds the points like water making river rocks.
I don't know what would happen if you give to 800-1200 silicon carbide. Start with finer aluminum oxide, single size?
I know someone who does 320, 500, then 12 micron, then polish. He does not use anything coarser than 320 and says it cuts great. I'm planning 320, 25, 9.
Please tell us more about the bee's wax. I'd love to work with something that does not stink.