Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Feb 28, 2008 1:37:54 GMT -5
I've been reading and reading and I'm just flamboozled about a few things. Three step, four step, soft rocks, hard rocks -- ARGH! The thing is . . . and my major question. . . how do you KNOW when a batch is finished the step? So my questions are -- IN GENERAL: [/b] [li] Is this step skipped for soft rocks? [/li][li]Are some rocks "borderline" -- for instance those that are 6 on MOHs? [/li][li]Are there some hard rocks that really shouldn't be tumbled in large grit because they will fracture? [/li][li]Is it better for some "tough" rocks to go to, say, a 46-70 grit? [/li][/ul] [/b] [li]How do you know when this step is done? How should the rocks look? [/li][li]Are there any rocks, in general, that should skip this stage? [/li][/ul] [/b] [li]Again, how do you know when this step is done? How should the rocks look? [/li][/ul] Last question, for now: People talk about reusing grit (slurry). This confuses me because the grit breaks down as you tumble, so how is it that you can reuse it? Thanks! Eileen |
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one80mike
freely admits to licking rocks
@(-_-)@ Princess Leia!
Member since February 2007
Posts: 908
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Post by one80mike on Feb 28, 2008 2:05:14 GMT -5
Hey Eileen.
STEP 1:
a) No they still need to be shaped, rounded off and smoothed off. they just won't take as long. Coarse grind does ALL of your shaping, smoothing and getting rid of big and small pits. All the following steps do is get rid of the scratches of the previous steps in preparation for the polish.
b) Not sure what you mean here, mate.
c) They will still need step 1 but you'll need to be more careful. You may want to slow your tumbler down so that there is a gentler action or you may want to add plastic pellets to step 1 to cushion your rocks. Amethyst for instance has a nasty repuation for cracking. I haven't tumbled it myself but that is what I have heard/read.
d) Generally the concensus is that the very coarse grits are best for larger tumblers. However, I run 3lb barrels and use 46 and do not use an 80 grit. I just run my barrels longer and use less grit after each clean out. As the 46 runs it breaks down to 80 anyway you just need to run it longer in between recharges.It's cheaper, it gets the job done and it's working for me. Others may choose to disagree.
STEP 2:
a) Remember there will very little or no change in the shape of the rocks the surface will just get smoother. I run rocks for 10-14 days in 220 in a 3lb rotary with plastic pellets.
b) Not that I know of. You need the 220 to get rid of the tiny scratches made by the 46 or 80 grit. 500-600 is too fine to do this.
STEP 3:
a) I run 600 grit for 10-14 days. Again this is longer than some others do but it does leave the rocks very smooth and ready for polish. There is nothing to "look for" you just need to give it enough time.
Last question: I don't but some may reused 80 grit as 120 grit and 120 as 500 grit. I am always afraid that there my be 1 or 1 piece of grit that have not broken down enough and could ruin the whole step. Polish on the other hand I do reuse and with great success.
In the end, you have to experiment a bit Eileen, and find out what works for you and for the rocks you are tumbling.
I hope this helps and I hope others add there thoughts and ideas.
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Post by Jack ( Yorkshire) on Feb 28, 2008 4:01:59 GMT -5
Hi Eileen , ALL as mike says above ,
Just think what you are doing smoothing a stone dovn to get it to polish.
If you jump a stage the next stage cant cope with the groves cut with the previous grit,
It has to be a continual process and you can feel the rocks are smoother, and see with a LOP
Yes its all down to experimenting and what YOU find works well for you, great ! so its all up to you !!
Have a "rocking " day
Jack
Yorkshire UK
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geogoddess
spending too much on rocks
Member since December 2007
Posts: 287
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Post by geogoddess on Feb 28, 2008 10:44:44 GMT -5
I'll add just a couple of things, since the guys have pretty much covered everything.
Even rocks that are about a 6 on the Mohs (Sodalite, for example) still needs some time in coarse grit. The stuff I'm running was in a coarse run 14 days in my 1.5 lb tumbler, 1 week in the 15 lb. Stuff that is even softer, fluorite (4), I did the whole run in less than 2 weeks. But I did not achieve a great shine... just frosted pieces.
I generally let things run until they've either fractured themselves out, or have been in the coarse for 4 weeks (or 6) until they've proved to me that they aren't going to fracture any further.
Prepolish... I've seen a few references, that if you take a rock out of the 500, and lightly polish it on a piece of leather or flannel, and it has the shine you're looking for, its ready to go on to the polish. I haven't done this successfully... but I've gotten some nice and shiny rocks.
I think when most people talk about re-using grit they are talking about one of two things...
1. reusing the final polish. I haven't had enough containers to keep the polish separate so I haven't tried this yet... but its my plan to try next week.
2. recharging 60/90 grit... when I check my 15 lb tumbler (which is dedicated to coarse), I pour out about 1/3 to 1/2 the slurry, I check the progress of the rocks. And then I add 4-6 tbs additional grit and a bit more water and rocks if needed. Everyone has a different ratio on this, I've noticed. I've seen quite a few folks say they jumpstart the slurry with a bit from a previous batch, or with shredded newspaper, just to get the right actions going sooner.
I hope this makes sense... I haven't had my coffee yet.
Like Jack said... experiment... and you'll find what works for the rocks you have. I've had rocks that were "finished" but I decided I didn't like them and they went back into the coarse grind for a week to start over from scratch. There's nothing that can't be fixed, IMO.
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Sabre52
Cave Dweller 
Me and my gal, Rosie
Member since August 2005
Posts: 20,494
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Post by Sabre52 on Feb 28, 2008 10:56:40 GMT -5
Eileen: Looks like everyone has covered this pretty well. First step, coarse grind is really the key to it all. Grind anything till you have nice rounded shapes and a smooth surface. It should be smooth and silky to the touch. Rest the stages are just scratch removal and polish and the longer you run each of these the nicer your stones will get. I do each of the following stages at least two weeks, probably longer than necessary. I reuse some of my slurry in the coarse stage to start out with a nice soupy liquid mix. This sticks grit to the stones better and gets the grind off to a good start. Lots of recharges on the coarse grit on hard rocks like agate too as I find in my 12 pounders, the grit is fully broken down in less than a week....Mel
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Feb 28, 2008 11:03:19 GMT -5
You've given me some excellent tips et al. Thank you! . . .Even rocks that are about a 6 on the Mohs (Sodalite, for example) still needs some time in coarse grit. The stuff I'm running was in a coarse run 14 days in my 1.5 lb tumbler, 1 week in the 15 lb. Stuff that is even softer, fluorite (4), I did the whole run in less than 2 weeks. But I did not achieve a great shine... just frosted pieces. Thanks. I've read a few posts from people who say you should skip the coarse with soft rocks. Probably works fine for them because they know what they are doing  This is very valuable info to me. I didn't know you could or should "rebreak" rock that was fractured. OH! VERY valuable info! At least it's some kind of guideline I can follow ;D Nod nod. The problem with experimenting is you kinda have to have a grasp of what you are doing in order to experiment. Sort of like giving someone a pile of car parts and a picture of a 2008 Mercedes and telling them to build it. The learning curve wouldn't be so bad if it didn't take the rocks so long to tumble. It's very discouraging to wait 2 weeks and then realize you royally screwed up -- somehow, but you really don't know how -- and have to start over again. Eileen |
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Feb 28, 2008 11:05:05 GMT -5
First step, coarse grind is really the key to it all. Grind anything till you have nice rounded shapes and a smooth surface. It should be smooth and silky to the touch. Another piece of important information! I didn't know this and it's something concrete to shoot for. Thanks! Now, if there are pits et al that will not come out with the coarse, then you should Dremel them out, correct? Then retumble in coarse? Eileen |
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Feb 28, 2008 11:12:42 GMT -5
Okay, this is what I have so far based on current replies:
1. Step one, coarse grind is really the key to it all. Grind anything till you have nice rounded shapes and a smooth surface. It should be smooth and silky to the touch. If it's fractured, either break it and retumble or continue to tumble until the rocks totally fracture by themselves.
2. Step two is a refinement of step one and removes the big scratches
3. Step three removes the scratches left by step two. You can test at this stage, but it doesn't always work: "lightly polish it on a piece of leather or flannel, and it has the shine you're looking for, its ready to go on to the polish". I think also that if you polish it and get a reasonable shine, then it should be ready for final polish?
Eileen
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geogoddess
spending too much on rocks
Member since December 2007
Posts: 287
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Post by geogoddess on Feb 28, 2008 11:14:39 GMT -5
With my first batch of sodalite, I broke it up into chunks, and threw it into the tumbler. Then I talked to my friend who's requesting the pieces, and figured out what size he wanted. So after the first week, I took out some of the pieces and did my best to break them down smaller, and yet still have a good range of sizes to get the right tumbling action.
So yeah, you can re-break the rocks. They may just need a little bit of extra time in the coarse, to wear their corners down.
Patience with the first step is key, like Sabre said. My 15 lb tumbler has been running since it arrived Jan 12th or so, with just coarse grit. 6 weeks? and the rocks just rotate in and out... There are a few rocks that have been in there nearly the entire time.
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Post by captbob on Feb 28, 2008 11:38:25 GMT -5
The learning curve wouldn't be so bad if it didn't take the rocks so long to tumble. It's very discouraging to wait 2 weeks and then realize you royally screwed up -- somehow, but you really don't know how -- and have to start over again. QUIT looking in my windows!!!  I've found the learning curve is half the fun! Laughed myself silly over some mistakes that I've made and have been very glad that no one else saw them ;D I still usually tell my wife as she gets a kick out of my newbie screwups, but hey, live and learn. I'm sure most here made a few first timer goofs, but ya learn from them. I never even had a tumbler until about a month ago, and now I have two 15# and two 12# loads running. I have a 25# bucket of 120/220 grit that I've never opened, and hope to maybe see it by April. I figure that I might have my first finished batches by June  but I expect to "Don" them! If not, well I will have learned something... I hope! patience grasshopper |
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Post by akansan on Feb 28, 2008 12:42:43 GMT -5
On the reusing slurry part - if you're needing to cushion a load, a bit of saved slurry from a previous batch quickstarts the slurry mix. I used it with some success on a load of apache tears. When I do this, I still use the same amount of grit that I'd use on a normal load...I'm just trying to protect the rocks.
But yes - DO reuse your polish. I mix 3/4 reused polish with 1/4 new polish.
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Post by Cher on Feb 28, 2008 13:00:46 GMT -5
I reuse my 500 grit, 1,000 ao grit and my ao polish. Have done it time and time again with excellent results.
I do save a bit of slurry from my 60/90 coarse grind and from 120/200 just to jump start those batches when I'm running them.
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huffstuff
fully equipped rock polisher
Member since August 2007
Posts: 1,222
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Post by huffstuff on Feb 28, 2008 13:05:33 GMT -5
Hi Eileen,
Yeah, I'm with you on the "but I won't even know the results for 2 months, sure is a long learning curve!"
The only thing I've heard different from the above advice is the one about the time to switch from prepolish to polish.... what I've heard is that you should put some polish on a cloth and polish really hard (not lightly). But really, if you can stand it, I would suggest just let it have 2 weeks in prepolish and move on to polish.
Good luck!
Amy
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geogoddess
spending too much on rocks
Member since December 2007
Posts: 287
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Post by geogoddess on Feb 28, 2008 13:08:57 GMT -5
Thanks for chiming in, Amy.... I can't remember where I saw the advice about the test much less the details |
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181lizard
Cave Dweller
Still lurking :)
Member since December 2005
Posts: 2,171
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Post by 181lizard on Feb 28, 2008 13:32:05 GMT -5
Last time I posted this pic...I took some major crap because of the glove, so let me begin by saying "You can all kiss my butt! "  This is a batch in step 1 and I was worried the slurry was too thick but a bunch of RTH'rs assured me it was about right. (I thought it might be helpful to Eileen.) I re-use slurry for step 1 as much as I can but I'm afraid in the later steps, I get a little wastefull and do fresh every time. Here's the thing Eileen...there are no "absolutes" in rock tumbling. There's a guide to get you going on your way and it's up to each of us to fine tune our methods. Some of us are so anal about each and every step we do...then there's some of us that fly by the seat of our pants! It's what ever YOU get to work for YOU! Why...one time, I totally forgot about a batch in step 1. No checking...no recharging...no nothing. Know what happened? When I finally looked at them...the grit had broke down so well, they had completed the final polish & were one of the nicest batches I'd done...go figure! |
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Post by captbob on Feb 28, 2008 13:41:03 GMT -5
I wish I had tought to use one of those gloves when I checked a batch of this red jasper and hematite the other day  The slurry was like your pic (maybe a little thicker) but blood red. It's gonna take a week to get it all out from under my fingernails!  I'll post a pic next time I check it... |
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Feb 29, 2008 1:31:20 GMT -5
QUIT looking in my windows!!! HAH! Okay, I'm gonna kick yah, captbob  I have ONE, count 'em - ONE, tumbler and no means to buy another for quite a while. I'm allowed to express impatience, dang it all!!!! By the time I get things going right, it'll be 2009!!!! Grumble!!! Eileen |
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Feb 29, 2008 1:35:55 GMT -5
Last time I posted this pic...I took some major crap because of the glove, so let me begin by saying "You can all kiss my butt! ". . . Excellent picture, Liz, and I *love* the gloves. My hands are a wreck -- cut, split, dry, chapped, and they hurt . There's not a lot I can do about it. I'm an artist by trade and I get my hands into all sorts of drying stuff, not to mention the wire I wrap all the time. I can't wrap wire with gloves on; you lose the feel. Hand cream is out because even if it's hypoallergenic, my skin on my face et al will break out. The 90 and 220 grits aren't so bad, but the 500 and AO grits feel TERRIBLE on my hands. Gets into the cracks and won't come out unless I scrub and that hurts. I'll wear gloves. Eileen |
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chassroc
Cave Dweller
Rocks are abundant when you have rocktumblinghobby pals
Member since January 2005
Posts: 3,586
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Post by chassroc on Feb 29, 2008 12:25:18 GMT -5
How do you know?  ? Experience is the best teacher! Try it. The base rules say 1 week for coarse, medium, fine and polish. You can follow that and get results. You will get better results if you keep rocks in coarse(46/70 and similar grits) until the rocks are rounded and smoothed to a pleasing degree. This has more meaning as you try it. Some rocks have pits which are hard to remove by tunmbling so you may want to grind these surfaces. two weeks and even more in coarse grit will give you better results. Subsequent stages take a week; some will do a stage for more than that but that is experience; the rules vary with the rocks and it helps to have experience and an idea csroc |
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but I expect to "Don" them! If not, well I will have learned something... I hope! 
I have ONE, count 'em - ONE, tumbler and no means to buy another for quite a while. I'm allowed to express impatience, dang it all!!!! By the time I get things going right, it'll be 2009!!!!
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