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Post by rockyraccoon on Nov 5, 2004 22:44:09 GMT -5
i'm struggling to polish the agate slices stoner sent me. i think because they are so flat and my wheels on the genie aren't getting all the scratches out. what do people normally use to polish slabs/slices??
kim
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deepsouth
fully equipped rock polisher
He who rocks last rocks best
Member since January 2004
Posts: 1,256
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Post by deepsouth on Nov 5, 2004 23:17:45 GMT -5
I don't have a Genie ....yet and ad to try another way to grind and shine a piece of pet wood I had found. Place grit on flat surface ( I used a piece of rock ) start moving in circular motion and use small amount of water , with newspaper underneath to prevent making a mess of work area I used a piece of leather with some cerium oxide to try polish afterwards. I also used some 1200 grit paper to try give it a very smooth surface.before the polish. I hope this helps Jack
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Post by rockyraccoon on Nov 6, 2004 0:28:47 GMT -5
jack - you go through all the grit cycles in this manner? how long do you think each stage takes doing it by hand. do you have to get a different rock each time you change grits? or continue on the same rock?
kim
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deepsouth
fully equipped rock polisher
He who rocks last rocks best
Member since January 2004
Posts: 1,256
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Post by deepsouth on Nov 6, 2004 0:58:03 GMT -5
The petrified piece I did like this was quite smjooth to start with , so I did the course grit twice. It does not take long at all to break down and become very fine. I did the 600 grit twice . it does become quite sticky when the water evaporates so regular small amounts need to be fed into the system. I found the polishing with a piece of leather the hardest part. That piece of pet wood was about 6 inches long and 3/4 inch wide and high. I was advised to use a straight edge to make sure there are no hollow areas . I spent about 2 days on that piece. I haven't done others yet as I am waiting for more supplies of finer grits . I do have a vibrating lap which is fine for heavier pieces. For the thinner slabs I need to get weights to be effective. You do not need to change to different rocks as you can do 2 rocks in one go if you so desire. I was just trying to get that piece done for rockhound clubnight Jack
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Post by stoner on Nov 6, 2004 1:48:43 GMT -5
Hey Kim. You can do most of the work on your genie. Do you have 6 or 8" wheels? It's easier with 8" wheels, but either way, you have to keep the slab moving. I use Jacks method after the grinder except I use a piece of 1/4" glass instead of a rock. (different piece of glass for each grit.) I use 80 or 60-90, 120-220, 400, 600, 1000, then go to 1500 sandpaper, then to a leather disc on my grinder. You can use the canvas pad on your genie. Sorry, I should have told you what was involved in polishing those agates.
Ed
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Post by rockyraccoon on Nov 6, 2004 2:04:53 GMT -5
ed it's all good - i'm learning - learnings good . this hobby is a challenge - i like a challenge! kim
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Post by connrock on Nov 6, 2004 8:11:09 GMT -5
Hi Kim, You can polish slabs in your rotary tumbler but even better you can get a shine like no other in a vibe unit. I've tried to polish slabs on my genie and had very poor results unless I actually formed them into a convex shape like a cab. Unless the slab is very small you can't fit it on each wheel without hitting another one.The wheels are just too close together. I don't like to polish slabs in my rotary's because it just takes to darn long but you can get great results. The trick to polishing slabs in a rotary is to make the slabs your priority.In other words,the other material you put in the tumbler is just to make the load work and you don't care about polishing the "filler".If the filler polishes up,,,,that's a plus.The filler should consist of very small pieces of material you have already roughed in.I save everything I can from a tumbling load down to SAND!!Some where along the line you will find it useful. Anyway,the material can be a little softer then the slabs but NOT harder.The size of the filler should be as small as a pea(or smaller) but not bigger then a good size grape. The size of your tumbler will determine the size slabs you can polish.In this case bigger is better if the slabs are large.You don't want to try 4" slabs in a 1-1/2 lb tumbler but they will be OK in a 6 pounder. In a vibe it's a whole different story and you can have polished slabs from start to finish in about 4-6 days depending on the condition of the slab after it was cut.Some saws cut a very nice smooth cut and others are a little loose and/or the feed isn't slow enough or whatever. I can go on and on with this and if you're interested just post it and I'll go through what ever you like with you. Tom
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Post by rockyraccoon on Nov 6, 2004 9:21:56 GMT -5
tom do they run the risk of fracture or chipping in the rotary? i don't have a vibe. i'd be so scared they'd chip and make me cry!
kim
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llanago
fully equipped rock polisher
Member since January 2004
Posts: 1,714
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Post by llanago on Nov 6, 2004 9:50:15 GMT -5
Kim, I have put all sorts of thinly cut pieces - slabs and things not necessarily slabs in the rotary - and they haven't broken or chipped. I always use lots & lots of those dreaded pellets. But, Tom's got it right - the vibe is the way to go 'cause it's so fast! May you should be a VERY, VERY, VERY, VERY good girl and you can slip in a vibe tumbler along with that saw! llana
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Post by rockyraccoon on Nov 6, 2004 10:12:23 GMT -5
or maybe i could slip through with one of those vibrating laps after dark - see there i go thinking like a very bad girl right off ;D - must be a good girl...must be a good girl....i may need a hynotist for this . kim
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Post by connrock on Nov 6, 2004 17:39:57 GMT -5
Hi Kim,,, Anything can happen in the tumbler but if you load it with the correct materials you lesson your chances of having fractures and chips. OK here goes,,,,, Inspect your slabs and make sure there aren't any lumps,etc on them.Most times when thr rock goes through the saw it kind of breaks off right when the cut is finished. Grind any of these "lumps" down being careful to not go too deep or the slab will will end up with a low spot on it. If the slab is fairly smooth and doesn't have ridges from sawing on it you can start out with either 220 or 400 grit. You can use either plastic pellets or as I suggested very small rocks of either the same or less hardness. Run the load and check it often until you get a matte finish over the entire face of both sides of the slab. Now you can go on with the tumbling cycle as you normally would. Hope this helps and if ya got quest's ,,,,,ask away,,,,,,,, Tom
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Post by docone31 on Nov 6, 2004 21:51:39 GMT -5
Flat against round produces dips. I use a flat lap for polishing flat surfaces and even then, I get frosted windows on large polishes. Tom is on the right track with tumblers. Many bulk cabachon makers tumble their cabs. John is doing it the old way. It works pretty well. You have a great deal of control doing it that way. It is also faster than you think. I saw an automatd slab machine. It would suprise you! It consisted of a 14" X .018 diamond wheel that was turned at an extremely fast speed. The slab was then brought by a metal track through what amounted to a stone planer. They were then placed into a monstrous vibratory tumbler for polish. The tumbler ran once a week. The diamond saw, and planer ran 24hrs a day for a production run. Large polishers use an arm with a rotating polishing pad. The arm is moved across the surface. It could polish 5' X 5' in one slab. Way out of my league.
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Post by cookie3rocks on Nov 6, 2004 23:27:50 GMT -5
I have been trying to polish some small, thin labadorite and turitella slabs in the vibe. I have tried to maintain a fill of softer (7 or less) stones so chipping and scratching stayed to a minimum. I also have some small tiger eye slabs (less than a half inch either way) and those are doing well. But the labadorite has scratched up badly! And it was so smooth going in. I started with 600 for 2 days and went to tripoli for 4 days, cerium for 4 days (both regular and optical). The labadorite just keeps going down hill. I have some sodalite in there also, it's ok, but not great. The labadorite is breaking my heart. I tried so hard to keep an equal mix on the MOHS scale, don't know what went wrong here. I'm doing a 24 hr borax burnish now, but I don't think it will help much.
cookie
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Post by connrock on Nov 8, 2004 19:20:04 GMT -5
Cookie,,,, I've never done any Labadorite so I can't help you at all with it. Sorry,,,,,, Tom
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