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Post by pauls on Jan 30, 2016 16:37:22 GMT -5
The results depend a lot on what you used in the stage before the oops moment and how long the rocks were rolling in that stage. Grits break down rapidly to very fine, so they turn into prepolish anyway, there's a recent thread by jamesp where he has gone from coarse grit to polish, just 2 steps relying on the grit breaking down. So, if you followed the instructions you probably had them in the 600 grit? for a week, it might be enough time to give a prepolish. See how it goes, if they are starting to polish you should start to notice the edges of the rocks shining, keep them in a bit longer. The instructions are a guide to get you started, experiment, see what happens, soon you will have a work flow that works for you. Going back to the instuctions, 1 week in the first stage is rarely enough, the fantastic results you see here are usually the result of many weeks/months in coarse, culling cracked stones that could carry over grit to the polish, even sawing and grinding holes and pits out. See the Agates and fractures thread a few down for some ideas from old hands. Paul
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Post by pauls on Jan 28, 2016 16:10:15 GMT -5
Still going still getting shinier, though its fairly slow. The protruding bits of agate are really shiny the flat spots not so much, more time would probably eventually do it.
I would say if you are looking for something to use to thicken up your slurry in the final stages and prepolish then this is a good option, due to the variability of the clay probably not so much for polishing. I have shown that clay from this pit will polish hard stones, eventually, no saying what other Kaolin sources are like.
Paul
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Post by pauls on Jan 28, 2016 15:50:35 GMT -5
I do the same as Chuck, though I use a 9 Kilogram (20pound) gas cylinder as a barrell. Hard to say the weight of stones though I can barely lift it, probably more than a cubic foot of stones say 50-60 pound, Each day I check it and grab a few handful of rocks out, this gives me an idea about how the grit is going, sort through and grind a few, saw a few cracks out, toss a few and put seconds aside for a seperate batch, recent additions that need more time just go straight back, then I top up with some new pieces. It doesn't take long.
After about a week or so I usually have enough really good stones to feed the vibe, it takes a bit longer to get a batch of seconds because I dont give up on very many.
Paul
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Post by pauls on Jan 27, 2016 16:33:52 GMT -5
Liability issues. The local government councils around here have to put up signs warning about trees on the roadside just in case someone runs off the road and hits one. Heaps of rock hunting spots (we call it fossicking) are closed because the owner of the land is scared of being sued by some idiot undercutting a bank.
Its time that the laws were changed so that the council can say you were speeding its not our fault you ran into a tree, or a land owner can say you built a tunnel into a sandy bank, I didn't put the sand there, you dug a tunnel, don't be stupid its your fault. Grow up and take some resposibility for your actions.
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Post by pauls on Jan 27, 2016 16:18:09 GMT -5
I tumble heaps of Australian Agate Creek Agates and they are exactly the same, I think they are born with fractures.
I put the small nodules in whole to remove the surface crust then saw them along any large cracks that appear, any surface fractures I try to grind out. Once I have removed the pre-existing cracks no more appear, though sometimes cracks are deeper than I thought and need a second touch up. I always start with largish pieces, that way if they need grinding or sawing to remove fractures there's room to do that and still have decent size finished rocks, the small pieces I saw off go back in to round off a bit then go into the seconds pile, I do a seperate batch of seconds when I have enough, kids still like them.. Some just are never going to be any good these I just put in the seconds pile.
I never hit Agates with a hammer, that causes fractures for sure and too much waste of lovely material, larger pieces say Apricot size I take a saw cut off centre so I can get a slab if its good, then I might saw the half pieces in half again. Really large pieces I allow plenty of room for cabbing thickness slabs, but if the material is nothing fancy I cut it into chunky pieces.
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Post by pauls on Jan 27, 2016 5:18:43 GMT -5
Cooler here today, so ran the tumbler all day. This morning I emptied a bit of the slurry out as it was a bit thick and because I thought I had reached the end of the road with the experiment, I added about half a teaspoon of Tin Oxide, tonight things are starting to happen, they are starting to shine. I wonder If I jumped the gun in pronouncing the experiment over, or is a teeny tiny bit of Tin is doing the trick?
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Post by pauls on Jan 27, 2016 5:11:46 GMT -5
A mud wrestling Gal and censored images, my goodness james,no wonder you knew that Kaolin was slick. Talkin about mud wrestling, when I was a teenager the town where we spent our summer holidays had a small abandoned open pit coal mine, half full of water so a great swimming hole, plus there was a depression on one side of the wall of the cut that was filled with deep slippery clay, great fun. They even shot a Coke commercial there. They brought in their own beautiful people but paid us to be extras standing around clapping and cheering as the beautiful people took running jumps into the mud pit, they didn't reckon on the weight of the clay filling the bikinis of the gals so that when they got out they were unclothed. Not that you would have known until they jumped into the water to clean off.
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Post by pauls on Jan 26, 2016 15:58:05 GMT -5
After about 36 hours in the Kaolin slurry the rocks have taken a reasonable prepolish all over. Kaolin clay a reasonable prepolish but I don't think its going to progress to a proper wet look polish, I think I will throw in a bit of Cerium with the slurry and see what happens, its an experiment after all.
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Post by pauls on Jan 25, 2016 20:40:50 GMT -5
I just had a look at the analysis of the clay from the pit. Its 30% AlO around 50% Silica, so it probably would not work with softer materials. Heck if it doesn't work I don't care, I can just go back to standard procedure. The clay is very fine and feels slippery even when dry, a lot like Talc, it makes a really smooth slippery slurry (try saying that rapidly). We'll see how they look after tonight, I can't run the tumbler during the day at the moment, its far too hot.
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Post by pauls on Jan 25, 2016 18:35:30 GMT -5
I have been searching for 500 Aluminium Oxide in Australia for quite a while but haven't been able to find any, I'm still looking but in the meantime........ In the Spirit of jamesp and his experimenting, I am trying a little experiment with a load that just came out of 600 grit SiC. I can't get 500 AlO here in Oz. but I know from my foundry hobby that fireclay is AlO so put a bit in with my rocks and ran it overnight, this morning the rocks are running in a nice slurry and unbelievably are starting to get a polish, this is just white Kaolin clay that I scooped up from beside the driveway outside the fence of a local clay pit. I didn't expect anything at all to happen and I doubt it would work with soft rocks because of probable Quartz grit contamination, but I am really surprised at what is happening with my Agate and pet wood. Zero cost polishing, what could be better. I will keep you posted about success or failure.
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Post by pauls on Jan 25, 2016 18:21:57 GMT -5
Nice idea jamesp, that way you don't get a tit on each tiny slab. How thick do you make your slabettes for tumbling? I have noticed that slabs tend to slide on their flats and consequently get thinner and yet still have very little coming off the edges, I try to make them thick and chunky so they roll, still a lot of thinner slabs that I have cut for cabbing but get rejected go in, I clean up the edges with the grinder so they can get moved on before they get wafer thin.
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Post by pauls on Jan 25, 2016 17:10:25 GMT -5
Great cabs again you are really getting into it. Check the setscrews holding the pulleys on, the pulleys could be slipping, also check the nuts holding the wheels are tight, they can spin on the shaft and rumble if not tight.
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Post by pauls on Jan 25, 2016 17:06:50 GMT -5
Great Cabs For the uninitiated, its West Australian and the white bits are worm holes. If you have ever picked up a piece of driftwood filled with shipworm (Teredo) holes then this is what peanut wood is.
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Post by pauls on Jan 25, 2016 16:56:54 GMT -5
Ruby and Sapphire are Aluminium Oxide and hard as hell, they need diamond to polish. I have made cabs out of star Saphires, Silicon Carbide sanding discs just don't touch them. There are people on the Sapphire fields here in Australia that tumble them using cheap Chinese Diamond powders, thats the bombs, not good cutters, the good cutters get sold to the Thias who cut them and call them Thai Sapphires. Topaz can be a problem because they have an excellent cleavage and can split down the cleavage in the tumbler, its really a waste of a Topaz if they are any good though as all you end up with is something that looks like a piece of tumbled glass. I know of people who do tumble them to clean them up so they can pick out the cutters for faceting but I wouldn't. Emerald is Beryl and quite fragile, I doubt it would tumble well.
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Post by pauls on Jan 25, 2016 16:42:25 GMT -5
It depends a lot on what you call Lava, as you can imagine lava being molten rock is very different from place to place, the only way to find out if your lava is suitable is to grab a lump and have a go. Good luck.
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Post by pauls on Jan 22, 2016 15:56:57 GMT -5
This (binding) sounds like the blade is at the end of its life, no diamonds on the side of the blade to keep a clearance in the cut. Or, as blades wear they tend to wear the cutting edge into a round shape, and the sides into a long taper, this can lead to binding but can be fixed by a bit of serious blade dressing to make the cutting edge square(ish) again. The blade could be dished, this happens from the tit left after the slab falls off running across one side of the blade, especially if you are running short of diamonds on the sides, turn the blade around occasionally to even this out.
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Post by pauls on Jan 21, 2016 15:41:03 GMT -5
"I would never put something that small on my bandsaw or a table saw---are there jigs or other holders specific for holding small objects?"
Lapidary equipment is totally different to woodworking equipment, no big sharp teeth to rip fingers off, a rock saw is just a really thin grinder, it wears through a stone with diamonds. they just don't do a good job of cutting skin or flesh, fingernails they will cut, I am always growing peculiar flat spots out of my nails. This is all done wet too as the dust (silica) is not very good for your lungs.
I would be looking to find a lapidary club to see how they do things, and see if its what you want to do before investing much in equipment. Though just lately my tile saw has been getting a lot of work in its intended use, and wide diamond wheels are fantastic for sharpening woodworking tools, they are always perfectly flat.
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Post by pauls on Jan 21, 2016 15:16:07 GMT -5
Leaky bucket, I can relate to that. Good to see you got things going, I can relate to a lot of your tribulations. Last week I was just finishing up for the day and as the last slab was finishing up I decided to sweep under the saw, so nudged the steel 5 Gal paint can bucket of oil out of the way with my boot and swept up, retrieved the slab and went inside to wash the oil and grot of my hands, when I came back I found a drop of water in the oil had eaten a pinhole through the steel and my nudge had opened it up. I was confronted with a huge and growing pool of hot runny oil spreading everywhere. Bonus though, I have been battling termites for a while and could never find where they were getting in, I have been baiting the wrong side of the house, the oil soaked down between the garage slab and the house foundations and suddenly I don't have termites, so I know that they are coming in under the garage slab, so I will relocate some bait stations.
I never stray very far when I am sawing. Murphy's law. "Anything that can go wrong will go wrong." it always will if you aren't watching.
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Post by pauls on Jan 20, 2016 22:11:18 GMT -5
I would be putting a sizable hole in the back too, saves precious metal, cost and weight. Translucent stones lets light through and if it flips over while wearing you can see the back of the stone. I agree with what has been said about making the setting to fit the stone, generally, but I think this nice design gives a fair bit of leeway as far as sizing a stone. I really like it. I do a few repair/replacement stones for a local jeweller and they are a real pain to get the size right.
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Post by pauls on Jan 19, 2016 19:48:22 GMT -5
Great job on the machine made cabs. Tiger Eye is actually Quartz, its a pseudomorph of Crocidolite Asbestos so not dangerous as Asbestos, but breathing in the dust will cause health problems called Silicosis. Breathing in any Silica dust is a bad idea, this applies to all the stones you have worked there.
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