Post #301145 by Tamapoutini on Mon, Apr 23, 2007 3:44 AM

On 2007-04-19 13:30, Tipua wrote:

So one of my questions is (mainly directed at Paipo) what substance do you put on river-type pebbles after you've sanded them? I put baby oil, but over night the stone just sucked it all up and dryed out (no pics, but you know what I'm talking about, no?).

My other question is about pendant holes. I found drilling the hole probably the hardest part about the whole carving process. I used various shaped diamond burrs to get through the stone, and I managed it, but there was a constant fear of breaking the stone. How is this more easily done? Are there special drill bits designed specifically for this purpose?

Also, how do you do those pendant holes situated behind the stone? You know, so you can't see the hole from the front?

Oh, and I nearly forgot... What is the difference between grit numbers with diamond burrs?

Gidday mate. I dont know where Paip' is hiding at - maybe he missed your questions. Im no expert with ordinary-old-boring-not-pounamu-river-rock ( -as nice as it is! :lol: :wink: ) but can maybe help with some of your questions. Ive been away myself & only just caught it.

#1: Not 100% that one. Im not sure what type of oil, etc you would use on common-stone..? I would think that any mineral oil/wax etc would suffice - It may come down to the final sand/polish still not being 'fine' enough to maintain the shine. Or perhaps the stone is just very porous (microscopically speaking) - I know this is one of the reasons that high-quality jade can hold such a high polish & not dry out the way you describe; its surface 'grains' (actually felted crystals) can be 'closed-up' to a very fine degree.

#2: Most carvers Ive met use a small ball/sphere to drill holes, although I do know of one guy who prefers to use a needle type burr. Remember to bevel the edge of suspension holes. A sharp edge will cut through cords in no time!

#3: 'Hidden-holes' or 'Ox-nose' holes to the Chinese inventors. Phew!
Firstly you mark them out; basically two dots about 1cm apart. You make a careful start at each of these points with the small (2-3mm) ball burr (I dont think the needle-type would manage this particular task!heehee) and gradually work the two small holes deeper, and coming together... You can also tilt them down slightly. The two generally 'meet' to form a 'V' at a depth of 2-5mm...with me? Once theyve met, use the same burr to soften any sharp edges within the hole, where the two meet (you cant see any of this; it is small & invisible & must be 'felt') Often a bevel can be taken of the egde of the starting holes once they are underway, this allows greater 'reach'/less shank-chafing as the angle is 'steep' (as far as most handpiece work goes) Hope this helps.

And lastly #4: Grit numbers on diamond cloth/burrs work much the same as with sandpaper. The higher the number, the finer grade it is.
I'd advise buying your 'range' of diamond cloth from the one manufacturer, as one companies '400' grit can differ wildly from another companies '400', etc... As a guide: 100grit is as aggressive as you'd want to go for jewellery type work and a decent range for most types of stone would be, 100, 400, 800, 1200 and from there on the fine-ness gets ridiculous; 40-80,000grit or something silly. You dont need them. Probably for diamond cutting..?

Generally burrs dont have such a range of fineness's to choose from but same rule applies.

*Still probably worth getting a second opinion though (P); Ive been away from the influence of other carvers for quite a while & may well be out of touch! :lol:

Back to the grind with you!

Tama :)

[ Edited by: Tamapoutini 2007-04-23 04:14 ]