Heya Tama!
Thanks so much for finding the time to answer my questions! I know you're a busy man, so I appreciate it immensely. I hope you find Paipo. He's probably on some sort of covert operation or collecting greywacke pebbles or something equally as dangerous... :)
On 2007-04-23 03:44, Tamapoutini wrote:
#1: I can help you with 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.
You're probably right about the stone's porousity (is that even a word?). I'd imagine most stones of volcanic origin being that way inclined. I actually bought some beeswax to see if I could 'clog' some of those microscopic pores. It merely made the stone feel... well, waxy. I buffed it up, but it's still not to the standard I want it at. I've put some lanolin on it and that seems ok... for now.
I don't want it too shiny though. I love the stone's natural rough texture.
#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!
I used a range of burrs and drill bits to finally get through the stone. I didn't want to use my ball burr too much as it's my favourite and I didn't want to wear it out.
As it happens I did, but not on this particular stone...
I picked up a whole bunch of pebbles by the river. The funny thing is that they're all so different from each other! Some are very pourous like pumice, whilst some are glassy, almost jade-like (resembling marsden 'flower' jade a little). They all feel so different while carving too. Even stones that look identical can have a completely different feel. Some others are just about impossible to do anything with at all. I guess the many varieties of pounamu are just the same, each with its own character and feel. So anyway, I've worn just about all my burrs out testing each stone!
I think a bevelled suspension hole not only prevents sharp edges, but has geat aesthetic value. It looks good too! :)
#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'...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.
I guessed it went something like that... only I assumed the 'V' to be a lot shallower - not really a 'V' at all. That's why I couldn't picture how it was done. So you actually go in quite deeply into the stone? How strong is the 'ox-nose'? I suppose it depends on a few factors like hole placement and stone strength, hey?
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.
I presumed as much... So is the general technique to use the coarser grades of grits to 'rough out' the piece, and the finer grits used for smoothing out your lines and achieving finer detail?
I don't really know too much about diamond cloth (actually bugger all)... I use burrs for pretty much everything. How is diamond cloth utilised?
Since I've just about completely worn out all the burrs that came with three of the El Cheapo rotary hand-tools I've bought (I just recieved a fourth for my birthday - a not so cheap Dremel - but it didn't come with any diamond burrs! :() , I've ordered some on ebay (cheap ones) and once they've worn out (a week or two?), I'll probably have to dust off my wallet and buy some quality burrs!
Thanks again Tama! As always you're a great help. You should probably start charging for all the handy hints you give out!
