@bentheduck I think I owed you some notes on lapping films.
Equipment:
Lapping film (not paper) at least these grits - 9u, 5u, 3u & 1u
Marble tile, granite or heavy glass. I use a 4x12” marble tile from HD. (2 pack $7)
Squeegee. I use an old, plastic gift card.
Spray bottle of water.
Clean hand towel.
All of my work is edge leading for honing. I only use spine leading strokes for stropping on balsa or leather.
My progression:
600 grit WD sandpaper (if needed for chip removal on edge). Can also use 30u lapping film.
1000 grit WD sandpaper (bevel set)
Bevel set using the burr method. Can also use 12u lapping film.
Lapping film- 9u, 5u, 3u & 1u (40-60 laps on each film)
Use a loupe or pocket microscope to watch your edge through the entire progression. Edge should run full length of blade. Each film removes scratches of previous film. When finished on 1u, the edge should be mirror smooth.
Finish on pasted balsa.
Pasted balsa- .3u and then .1u (Chromium/Iron Oxide) 40-60 laps each balsa. Wipe blade when changing media. Do not cross contaminate the compounds.
Maintenance:
50 laps .1u balsa after shaving. 12 laps on leather. Then 50 on leather before shaving again.
I’ll find you the videos I used also.