More faceting questions from the Mail Bag:
Cat hair scratches are killing me on my piece of spinel - been working on polish off and on since Sunday. Using 50k diamond on BA5T (crystalite in syringe - would you recommend switch to voodoo 14k/50k/100k, corian, darkside?) I've tried different pressures, different speeds, cleaning lap and re-applying, wiping off, change of direction, long sweeps, short squigly sweeps, polishing on area closest to mast, polishing on area closest to me... Read several tips from stone chats - just finished spending time trying slow slow speed close to center of lap with light touch. driving me nuts - what would you do? David
Hi, David,
Thanks for the note.
First, you’ve done the right thing pursuing technique changes as well as “recipe” changes (and hopefully first).
The suggestion to use “slow speed close to center of lap with light touch” is just a particular combination of techniques, and it doesn’t appear that the specific rationale was offered for WHY to do that particular combination.
In my experience, using an uber-light touch is a specific shift is often useful with oxides, but not diamond. IMX, an uber-light touch, when using diamond compounds, is more likely to bring the cat-hairs than to eliminate them. I have demonstrates causing cat-hairs in this way.
I personally despise el-cheapo diamond compounds that are mostly grease. That’s one of the reasons I brought Voodoo out. It’s something close to 20% diamond by weight.
However, I don’t use diamond compound on my BA5T (not even voodoo). My preference on BATT and 5T laps is loose diamond, with either 3-in-1 oil or sewing machine oil.
I usually demo this at the Academy using a chunk of quartz crystal with the edges chamfered so if I get clumsy with my grip I don’t gouge the lap.
Using 3-4 drops of oil and the Quartz, spread the oil around the lap until the coating is uniform, then dry that just a bit with a tissue, if necessary. You want just a thin film.
I use a toothpick as a tiny “shovel” to put little bits of diamond around the lap until it’s “freckled” with them. Then, use the quartz to gently smash and rub the diamond into the surface of the lap.
If you get too much, use a tissue to wipe some off . Then, just polish on it.
Also, I want to mention sometimes, the problem is the piece of material – just finicky. This is especially true of synthetics, and particularly the cheap-source ones, for some reason.
One thing I would suggest, if it’s driving you nuts, is to try a different piece of material (confirm to yourself that you’re not dealing with a contamination or setup issue). Dop a differently-sourced bit of the same kind of rough; cut a couple of facets, and polish them.
This alone sometimes gets me back into the groove if I’ve gotten all fuzzed-up over a troublesome piece. You’d be surprised how much emotional state and confidence influence polish – and how easy this little side-trip can put you back on track.
Finally, I recommend experimenting with different-sized diamond particles. You could go to Voodoo (on anything), but 14k instead of 50k, just to see how your weird material behaves. I once polished a nasty CZ with 14k Diamond powder on a sheet of mylar, with no lubrication. Trying that was based on a tip from a friend.
I hope this helps. Please write back to let us know how it shook-out.