copiahdad
having dreams about rocks
Member since April 2012
Posts: 72
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Post by copiahdad on Jun 13, 2012 12:44:07 GMT -5
Ok, got a question. I'm finishing up my first batch of stones in my new Lot-O vibe tumbler. I cut a lot of slabs, rough shaped them into free form cab shapes on an 80 grit diamond wheel then loaded them (with some ceramic filler) and followed the instructions in Randy's sticky.....120/220 2 days, wash and then do 120/220 2 more days, then wash and 500 for 2 days, then wash and burnish/prepolish for a day, then wash and polish for 5-6 days. I'm on the 3rd day of polish stage right now. On the third day of polish I scooped up a few stones to check their progress and much to my dismay, all three I pulled out had quite visible fractures. However, after slabbing and rough shaping, there were no fractures were visible. After washing the stones after the 120/220 cycles, there were no fractures visible. Then after washing after the 500 cycle, there were no fractures visible. Then after the washing after the burnish cycle, there were no fractures visible. But during the polish stage, fractures are very noticeably visible. They are so bad you can run your finger across it and feel the crack. Is the normal? Did I do something wrong? Were the fractures there, just minimally noticeable and the continued vibration make the the fractures worse and more noticeable. I've cut a lot of cabs on a cab machine and never have had a problem with fractures just appearing where I hadn't seen them before......at least to this degree.
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herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on Jun 13, 2012 13:48:22 GMT -5
my experience (admittedly short) is that it depends on the material.
Hard, solid material polishes well in the vibe, but aventurine, brecciated jasper, granites etc that may have small cracks or varied hardness do tend to develop these fissures.
My theory is that the polish is much smaller particles than other stages and it can work into small cracks easier.
I've started removing rock from a stage prior to polish if I detect any cracks at all - however small.
I find that varied hardness and material with very small cracks polishes more consistently on a wheel with a light touch. In the vibe, there are materials that work well and some - I find - that are hit-or-miss.
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snuffy
Cave Dweller
Member since May 2009
Posts: 4,319
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Post by snuffy on Jun 13, 2012 14:10:32 GMT -5
I run 2 lot-os constantly and have never encountered that problem.The white polish is more noticable in cracks,but to have seen none until the polish stage is unusual in my experience.One time on one,the counter balances got out of line and the loto had a violent action that broke some of mine,but only happened once. Check and see if they are lined up.
snuffy
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herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on Jun 13, 2012 14:56:22 GMT -5
I see it with certain materials, and they show up worse in polish. For example, some epidosite/unakite (granite) can do this to me. I've even had them break apart in polish stage and have been find in all other stages. I run a UV10 and it polishes most everything really well but I do see this happen with certain material.
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rockingthenorth
fully equipped rock polisher
Member since January 2012
Posts: 1,637
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Post by rockingthenorth on Jun 13, 2012 18:36:18 GMT -5
I have this problem too. not only cracks in the polish stage but sometime chunks break out funny because I was going to ask what speed they set theirs on my husband has mine on the fastest speed so I was thinking thats what was doing it.
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Post by NatureNut on Jun 13, 2012 19:18:50 GMT -5
My experience isn't with the Lot but a UV-10. The only thing I can offer is the possibility that the amount of rock has decreased over the course of the stages. There was once a debate on here whether it is weight or the level of rock and whether adding filler such as more rock that is at that stage or ceramic or plastic pellets will help. Some people add marbles but it was noted that they may release gas from bubbles inside the glass and a tiny bit tsp of baking soda can help there.
The slurry will be thinner in later stages and therefore cushions the load less. I've heard of people using cut up pieces of leather or felt to help cushion there. Also, using rubber tile spacers (little Xs) is a good cushion.
I hope some of the more experienced members who are Ace tumblers can weigh in and tell me if anything I've mentioned is on the right track to help. Jo
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snuffy
Cave Dweller
Member since May 2009
Posts: 4,319
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Post by snuffy on Jun 13, 2012 19:42:03 GMT -5
How full was your loto barrel? In mine,I fill it to the top and turn on and if there is any more space,add smalls until it wont hold anymore without impeding the action.This is why I tape the lids down. I've got a large supply of rocks waiting which is why I dont use any other filler.There is no knocking or falling to cause problems,they just roll with the flow.
snuffy
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copiahdad
having dreams about rocks
Member since April 2012
Posts: 72
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Post by copiahdad on Jun 13, 2012 21:16:09 GMT -5
I filled my Lot-O up to about where the curvature changes and starts to get narrow. I used quite a bit of filler (ceramic pellets) to go with the roughed out cabs. I also noticed that as I proceeded from stage to stage, the level of the rocks in the barrel decreased I sure because of the grinding process. However, I never added any other rocks or filler to keep it up to the original level.
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Post by connrock on Jun 14, 2012 7:46:26 GMT -5
In my opinion,the fractures had to be there right from the start.They may have been tiny but they were there. The Lot-o HAS to have enough weight to work properly so a guess would be that you didn't have enough weight in the barrel which can cause a more violent action,thus exposing the tiny fractures. As mentioned before,you should also check the counter balances to make sure they are lined up.This too WILL cause a violent action. It's a process of elimination to find the real problem but these are my best guesses. I have done several Brazillian Agate,Mooakite Jasper and Green Moss Agate guitar picks 1-3mm thick without any fracturing but inspected each slab carefully before going through any tumbling. Here are some Brazzilian Agate picks from 1.5-3mm thick. You can see a small "chip" out of the top of the one at the upper right but I saw that in previous stages and let it go for the "ride". The others came out fine,,, Good luck,,, connrock
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herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on Jun 14, 2012 12:36:17 GMT -5
Tom! Hey man it is good to see you around! FYI We are headed your way in a week!
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Post by Hard Rock Cafe on Jun 14, 2012 12:42:09 GMT -5
I agree with Tom (connrock). In my experience (UV-18), the cracks are there all along; it just takes the fine polish to make them visible. If the stones are wet, the water fills in those hairline cracks so that they are extremely difficult to see.
Chuck
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snowdog
fully equipped rock polisher
RIP David Fildes, aka: snowdog
Member since January 2005
Posts: 1,527
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Post by snowdog on Jun 14, 2012 13:34:40 GMT -5
mine is a little different because I have a 50# vibro sonic but the one I use for polish I have set to viberate the least amount possible ( set the counter weights ) -- if I leave brazilian slabs in long enough I can pull them apart on all the banding lines ---- maybe 5-6 days in polish is too long ---check them in two days and see if you like the polish , also on what the others said -- maybe put some more cushioning in
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