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Post by pauls on Mar 27, 2024 23:13:57 GMT -5
pauls Thanks for posting this. I'd already seen and bookmarked her garnet illustration. Garnets, along with the feldspars, are two of the most complex minerals used for gems and the feldspar group illustration is a welcome addition to my collection. Garnets have been a special interest of mine for years. Differentiating garnet species in cut gems is difficult since there's so much intermixing (miscibility) between species and duplication of colors. If it's of interest to you, Dr. William A. Hanneman published a book some years back called "Naming Gem Garnets." It came with a fold-up "pyramid" called the "Rosetta Stone of Garnets" that lists garnet species by color and RI. I've found it immensely helpful. Unfortunately the book is out of print, I think, but a used bookseller may have a copy. You can still get that book, $40 Australian plus $100 postage, Nahh, will give it a miss I think.
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Post by pauls on Mar 26, 2024 19:40:43 GMT -5
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Post by pauls on Feb 12, 2024 18:38:00 GMT -5
I like the plywood sphere, now it would be pretty cool if you could make a rock sphere made out of glued up slabs! Patty That would be definitely possible. Edit to add, Epoxy 330 would be the glue of choice.
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Post by pauls on Feb 12, 2024 18:35:44 GMT -5
I wouldn't worry too much about getting spares for the Graves, apart from the casing everything else is just off the shelf stuff, As long as there's nothing broken or badly worn it should get you on the road. Bearings are cheap if you need them, dops can be made by any half competent machine shop, Know someone with a 3d Printer you can print index wheels. The motor is a standard induction motor, it might need bearings greased or oiled and the capacitor if it's capacitor start may be near it's end of life but if you take the Capacitor to an electric motor repair shop you will probably get one for $10-$20. Might be even cheaper from an electrical wholesaler. Use it as a starter machine learn the craft and keep your eyes peeled for the machine of your dreams, you wont lose money on it.
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Post by pauls on Feb 12, 2024 18:20:32 GMT -5
Quite clear to me Bob, That's what I do too, sometimes you can see that by the time a deep cleft or hole is ground out there will be nothing left, Often by removing the bad piece you can salvage a fair chunk of rock. I saw most of my rocks rather than smashing them, I am a tightwad and turning nice rock into shards is anathema to me, big pieces get cut into thick slabs which are then carefully broken along existing cracks with a cold chisel, this ensures I remove cracks and don't put more cracks in the material.
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Post by pauls on Jan 24, 2024 16:20:39 GMT -5
Gday from Australia, You can never have too many rocks, just not possible.
I haven't tumbled Sodalite so can't comment apart from that soft rocks can be difficult to tumble. Amethyst can also be difficult, it tends to chip easily. You can get around this by making things gentler by using a lot of filler, anything small will do, some good fish tank gravel or those glass beads that people put in vases.
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Post by pauls on Jan 10, 2024 16:41:15 GMT -5
I agree about getting a good faceting machine, consider it an investment, they hold their value. Look around for a second hand machine, the price of a good machine will still be close to new but the laps and bits and pieces that often come with a second hand machine can be a gold mine.
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Post by pauls on Dec 27, 2023 17:13:10 GMT -5
Definitely factory made. I remember seeing lots of these shaped barrels advertised back in the day (1970s). I just had a quick look through some old magazines but I couldn't find an ad any of them. I guarantee if I was looking for an old faceting machine ad that this tumbler would be all I could find.
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Post by pauls on Dec 18, 2023 21:07:16 GMT -5
Oxalic Acid to remove any iron (rust) stains. Oxalic acid is sold as deck cleaner, Check the label. Also iron Out.
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Post by pauls on Dec 7, 2023 18:13:57 GMT -5
An ordinary nut will do just fine, as long as you get the correct thread type. You could also try taking the threaded bit out cleaning everything up and applying some locktite thread sealer. For locktite to work surfaces have to be clean, really clean, you would probably need to clean first with some kerosine or petrol, or white spirit and then a final clean with some acetone.
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Post by pauls on Nov 23, 2023 15:26:44 GMT -5
They're pretty expensive aren't they Dave? I had a Geologist friend stop in on his way to a his job at a Gold/Uranium mine, he had a company one of these in his vehicle, lot's of fun waving it around at some of my stranger specimens.
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Post by pauls on Nov 15, 2023 23:19:09 GMT -5
Was the thin Al plate attached to the shaft or did the shaft spin in the hole in the plate?
If it spins with the shaft it's there to sling water off the shaft before it migrates down the shaft to the outside, if the shaft just turns inside the hole it's only a physical barrier to stop spray. I think I would go with both options, something rotating on the shaft to stop water migrating along the shaft as well as maybe a rubber gasket sort of thing to stop spray out the hole. You could probably get hold of a steel washer to use as a slinger and a bit of rubber inner tube with a nice neat hole for the shaft to stop spray.
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Post by pauls on Nov 10, 2023 23:56:52 GMT -5
With an ordinary grinding wheel you can reverse the wheel to get a bit of extra mileage, you would need to reverse rotation to do the same with a flat lap though, I would go with Jasons suggestion and get a new one.
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Post by pauls on Nov 10, 2023 17:38:48 GMT -5
I'm not sure what is happening with those frosted bits. The polished pieces don't look like Amethyst to me, more like Rhodolite Garnet.
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Post by pauls on Nov 5, 2023 17:02:32 GMT -5
It might be easier to source or get made a couple of pulleys.
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Post by pauls on Nov 5, 2023 16:56:47 GMT -5
Just leave them in there for a longish time will take the edges off. FWIW I use small stones as media, why waste money grinding something away for no return. My small stuff stays in there for a long time (and a good time) No idea how long really as it just keeps going. It does eventually go through all the stages but not until it is worthy of gracing my higher grits and polish. ie no holes, cracks, or chipped edges.
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Post by pauls on Nov 2, 2023 17:59:38 GMT -5
I repaired a Scottish brooch some time back, It was missing a bell shaped agate. The brooch had two bells I was tasked with replacing a missing bell. I had to shape the surface of one of my grinding wheels to even be able to cut a bell, but the biggest problem was finding an Agate that matched, I cut several rejects but eventually I used a nice black and white Botswana Agate.
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Post by pauls on Oct 19, 2023 18:04:46 GMT -5
I just use a pillowcase or flannelette shirt, it traps 99.9% of the gunk. We don't have big brown paper shopping bags in Australia.
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Post by pauls on Oct 11, 2023 19:07:53 GMT -5
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Post by pauls on Oct 2, 2023 23:32:58 GMT -5
Drying needs to be an extent that the precipitate from grinding is dry and shows up in the scratches. This is a high dome Montana (almost 10mm) that I completed today. Despite careful inspection, I needed to go back to my worn 80 6 times. I think we've all done that.
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