The grinding wheel: I use a 100 grit SIC grinding wheel, not diamond, but either works just as well.
These 2 photos show how I have met in the middle of the stone, and it is now a level dome. Unfortunetely, with a person being taught in person, hands on, it is almost impossible to show exactly how that happens, but hopefully the photos help you a bit.
For the remaining steps of making cabs, EACH STAGE will be repeated in the same exact way you did the grinding wheel. After each and every stage, dry the stone completely, and check for scratches from the previous stage. The most common areas to have these scratches is right in the middle of the face of the stone, and along the girdle. The hardest ones to get rid of, are the grinding wheel scratches, they are deep, so will require more attention to detail. If you are having a hard time getting rid of the scratches in the middle of the stone, it is highly likely that your dome is not level, and you are not actually hitting the middle of the stone on the wheels.
THINGS TO REMEMBER WHILE CABBING:
1. Moving the stones constantly - prevents "flat" spots on your cab - do not let your stone sit too long in one spot on the wheel, keep it moving
2. Make sure to dry the stone, and check to see you have removed all scratches from the previous round
3. Make sure you also remove scratches from the girdle, this presents a cleaner, prettier cab
4.If you are doing them by hand, like I do, clean up the backs of your cab as well, get rid of as many scratches on the backs as you can. If you are using a dop system, you will have to remove the cab from the dop stick in order to do this.
5. If you have scratches, don't assume you can remove them on the next stage, they do not always come out. It gets progressively harder with each stage to remove deep scratches, and at some point, impossible.
6. Scratches on your cabs will create a dull, no shine cab.
MY RULE OF THUMB:
Just when you think you have removed all the scratches from your cab.....go over it again, to be sure, on that stage.
WHAT I USE FOR PROGRESSIVE STAGES
100 grit SIC grinding wheel
100 grit SIC belt
220 grit SIC belt
320 grit SIC belt
400 grit SIC belt
600 grit SIC belt
If you are using diamond wheels or belts, these numbers may be different. BUT, the system is the same, the larger the number the finer the grit, and you must progress from course to fine to get a pristine finish.