meviva
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Post by meviva on Oct 30, 2013 13:12:19 GMT -5
I just opened my first 120/220 batch and I am not happy with the results. I have been running 60/90 batches until I had enough to start a 120/220 batch. The rocks have been tumbling in 120/220 for 10 days and they are not as smooth as they were when I put them in. I used some plastic pellets to cushion them. I may have had the barrel too full and not enough pellets....maybe they were in there too long. Any ideas? Should I take some out and add more pellets and run it again? Any help is appreciated.
Thanks, Andrea
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Marie
starting to shine!
Member since March 2013
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Post by Marie on Oct 30, 2013 18:18:59 GMT -5
Pictures? What do you mean by "not as smooth as they were when I put them in"? Are they chipped? How full is the barrel?
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meviva
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Post by meviva on Oct 30, 2013 18:35:08 GMT -5
They are not chipped. They have a rough feeling...you can't see it...just feel it. I just opened my other barrel that had 60/90 in it. Those rocks are very smooth...not ready to move to the next step but they feel slick. I thought after the 120/220 those rocks would feel very slick. The 120/220 barrel was very full, there was still grit in the bottom of the barrel after 10 days. I don't know if I should put them back in 60/90 or do 120/220 again with fewer rocks in the barrel. Can I use the pellets again in 120/220? or do I need to use new ones?
Thanks
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rolanstones
noticing nice landscape pebbles
Member since August 2013
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Post by rolanstones on Oct 30, 2013 20:03:31 GMT -5
I am new to tumbling myself, but I had problems on my first batches with the use of plastic pellets. It could be me, but I am getting much better results by using ceramic of both small and med size to fill the space, and running at 3/4 full with just enough water to almost reach the top layer of rock, about 2/3.
Grit that remained is also what I experienced with the plastic pellet, like it was buffering the grinding ability.
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Post by Drummond Island Rocks on Oct 30, 2013 20:07:02 GMT -5
what type of rocks are giving you the problem? Granite and any other rocks that contain varied hardness minerals will create that type of finish and typically it gets worse as your grits get finer too. Unlike a solid agate that is all one hardness the minerals in granite grind away at different rates creating a non smooth surface. I could be way off but I have never had that happen with any solid material (agate,jasper,quartz etc..) before so I am just guessing.
Chuck
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meviva
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Post by meviva on Oct 30, 2013 20:11:39 GMT -5
Hmmm maybe that's it. I have some small and large ceramic pellets. How do I know which ones to use? The rocks range in size to pea size to around golf ball size. Is there something I need to do to them before using them? (I think I remember reading something about putting them in the tumbler by themselves first....for how long?)
Thanks
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meviva
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Post by meviva on Oct 30, 2013 20:16:22 GMT -5
It's a mixed batch of jaspers, agates, amethyst, tiger eye and others. They all were very slick after taking them out of the 60/90, I couldn't believe how smooth they were. Now they just aren't like that. I really think I had the barrel too full and they didn't have the room to tumble properly.
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Post by pghram on Oct 31, 2013 8:45:27 GMT -5
If you have a good mix of sizes with a good percentage of smalls you should not really need the ceramics in 120/200, in my opinion, even though they will not hurt the process at all. That's unless, you have the barrel too full. I like to keep mine 3/4 full for all stages except polish.
I might add enough plastic at polish to bring it to a slightly higher leven but I let my polish (Tin Ox) run for 2 to 3 weeks (rotary). It's over kill but the results are great.
Like you, I also run my grits for 10 days. The longer runs give the SiC a chance to break down to a much finer grit, so in this way, you are over lapping, so to speak. The 120/200 probably was more course that the 60/90 at finish, but the over lapping is a good thing in my opinion.
But, in 10 days, it should have definately smoothed them out much more. So, base upon you original post, some things I would sugest:
1. I never use plastic in 120/220, it's not needed (in my humble opinion) & may be slowing things down. 2. Make sure you don;t over fill the barrel & make sure you have plenty of smalles (stones, pea gravel, or ceramics). 3. Make sure you get the water level correct. Too much water greatly slows down the process, you're doing more washing than grinding/sanding.
I hope this helps, don't get discouraged, keep at it & be patient.
Rich
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meviva
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Post by meviva on Oct 31, 2013 16:22:25 GMT -5
Thanks Rich.....Last night I loaded up the barrel with fewer rocks, the plastic pellets and 120/220 grit. After reading your post this morning I probably should have left the plastic pellets out. I am also hoping I didn't put too much water in. I will check it in a few days and see how things are going.
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Post by pghram on Nov 1, 2013 12:02:59 GMT -5
Just keep at it, maybe make some notes, and eventually you will find the process that works for you.
Rich
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meviva
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Post by meviva on Nov 1, 2013 14:05:59 GMT -5
Thanks for the help.
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Post by Jugglerguy on Nov 1, 2013 14:21:07 GMT -5
I'm assuming that you're using a rotary tumbler. I only do 60/90 in my rotaries and then go to a vibratory tumbler for all the other stages. Therefore, I have only used plastic pellets in the first stage, but I'm not going to use them again. I always end up with grit that hasn't broken down after using pellets.
I can't imagine what would make the rocks worse after 120/220 though. The only thing that makes any sense is what Chuck (DrummondIslandRocks) said. Although the undercutting that he described usually doesn't occur until the 500 stage for me. You mentioned what rocks you have tumbling, but you haven't said if they were all affected or if just some of them degraded. I think it would really help us to see some pictures.
I also don't think that overfilling would cause the rocks to get rougher. That should just slow the process down.
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Mark K
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Post by Mark K on Nov 1, 2013 17:57:54 GMT -5
Grit contamination?
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Post by pghram on Nov 1, 2013 19:32:42 GMT -5
We will probably never know for sure, but if you let 60/90 run for a while it gets finer that 120/220, so if the tumbler was too full the 120/220 would be more course & not break down as fast because the process is slowed down. It's fun to theorize about these things :>)
Rich
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meviva
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Post by meviva on Nov 3, 2013 21:21:56 GMT -5
Jugglerguy....the rocks were very slick when I started the 120/220 stage. After ten days they were not as slick. You can not see it, only feel it. There was still grit in the barrel that did not break down. That is why I think the barrel was too full. I restarted the barrel with fewer rock but left the plastic pellets. If they are not better after this round I will remove the plastic pellets and try again. I think what Rich is saying is what happened.
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Post by Jugglerguy on Nov 3, 2013 22:46:39 GMT -5
What he said does make sense, but my guess is that the plastic pellets caused the problem rather than the barrel being too full. Whenever I've used plastic pellets I've had the problem of the grit not breaking down.
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meviva
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Post by meviva on Nov 3, 2013 22:55:01 GMT -5
Ok maybe I should take out the pellets and start over tomorrow instead of waiting.
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Post by Jugglerguy on Nov 4, 2013 7:30:37 GMT -5
No, I'd run them and see what happens. If it comes out the same as last time, you'll know it was the pellets and not the volume. If you take them out now, you'll never know.
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Post by connrock on Nov 4, 2013 8:54:30 GMT -5
I'm a little late here but maybe I can help,,,, Where to begin??? LOL First off doing agate and jasper together is pretty muck OK but the tigers eye mixed in with them isn't.Tigers eye comes out best if it's done by itself and doing it with the harder material(s) will give bad results. To me,,,,one of the most difficult points to get across to a beginner is how important it is to have a LOT of small rocks in any given load.It's hard for all of us to sacrifice the room in a barrel with small (maybe) unwanted rocks but they are a key part in the whole tumbling process. These small rocks create "surface contact" between the bigger rocks and the grit that grinds down the rocks.It doesn't matter what size barrel you have,,,a 1-1/2 pound barrel or a 50 pound barrel,,,,you must have AT LEAST 1/3 of any load being small rocks.If you don't have small rocks then ceramic media is used. Plastic pellets are used as a "cushion" and not as a filler as ceramic pellets are. IF plastic pellets are "needed" they are usually not used until a 500 grit stage.I say "IF" because in most cases plastic pellets aren't used at all. Although many people use ceramic media as a filler and or cushion,,,I try to use small rocks in every stage.
Having any "noticeable" grit in a barrel after 7-10 days,in rough stage, in a rotary means something was done wrong. Too much water,too many big rocks,barrel too full,plastic pellets used,belt slipping,too much grit used. There should be NO sign of grit after 7-10 days of roughing!!!!!!!!!!
Something I had a problem with when I started tumbling rocks was trying to determine if the rocks were really smoother then a previous stage and if they were really ready for the next stage. I got a 10 x jewelers loupe and when I got a rock that was perfectly roughed in I looked at it through the loupe.I put a piece of masking tape on it a wrote a big "R" on the tape designating that rock as being finished with the rough stage. I did this with a single rock after each stage and set them in a row on a shelf. This may seem extreme but I was VERY new to this and had NO ONE to help me,,,,no internet,no one nearby,,,no nothin,,,but a few magazines on rocks and tumbling.
I don't need a jewelers loupe to tell me what's going on with my tumbled rocks anymore but it sure answered a lot of questions back then.
One thing for sure,,,you have to stop using plastic pellets in the first few stages,,,,,, connrock
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meviva
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Post by meviva on Nov 4, 2013 12:45:14 GMT -5
Thank you connrock for the great information. I do know about putting small rocks in the barrel from this forum. I have a bunch of small rough that I got from a rock shop for that reason. I put some in every time I start a new 60/90 batch. The 120/220 batch that I am having problems with has the small stuff that has come out of the 60/90 batches. You mentioned that too much grit could have been used. I put in 10 Tbsp. in a 6 lb. barrel as the instructions stated. I think I've read somewhere on here to use 1 Tbsp. per pound. Is 10 Tbsp. too much?
I really looks like I need to get rid of the plastic pellets in the barrel...but Jugglerguy I understand your point.
Andrea
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