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Obsidian broke my heart, broke me down, then rebuilt me into a real rock tumbler. But I didn't do it alone - a friend showed me his secret and then I built on his ideas, threw out the rulebook, and began to coax a mirror shine on that sh*t. Hang in there. Implement the advice you're getting until you find what works for you. Don't shy away from experimenting - I'd never have gotten my results if I'd kept running into the same brick wall.
When you hear the tumblers snicker, take heart. Anyone who has polished obsidian has been there, but with perseverance you'll triumph. I've posted a number of times about my process, and shared photos, so I'll spare the forum another repost of my stuff. Looks like it is still available if you search for it, so I'll just kick-start it with one link, if you're interested: Near the bottom of the first page on this thread is a post with a couple of my photos, including an obsidian batch that came out well: forum.rocktumblinghobby.com/thread/82195/rocks-polishing-frustrated
Here is a pic from one of my early successes getting obsidian to shine. On the right is the aquarium gravel. (This gravel had been through a few course grinds and had already been polished in a 7 mohs batch, then sorted to get the best stuff to run with obsidian.) You are looking at the actual full load of what came out of my Lot-O, using just two steps - a rotary coarse grind to get the shaping, then the second (and final, step) in the Lot-O using 1/4 tsp. of AO 500, a 1/4 tsp. of Metamucil, liquid hand soap, and very little water. With obsidian, rather than 24 hours (which is enough for most 7 mohs stuff), it usually takes about 48.
Ahh - to each his own. I agree on less grit than the instructions call for - I only use a 1/4 tsp of AO 500 on my second (and final) step in the Lot-O, but I don't care for ceramics as much as the quartz/agate aquarium gravel that gives me my smalls. It feels like I get a deeper shine with them (and I just like them!) but sure, ceramics work too.
Ooh, I'd like to try the agate/quartz gravel - where do you buy it?
Petco or Petsmart carry it. Look for the bags of large-sized, rounded gravel. You can presort, or just dump some in with your next coarse grind and sort it later to pick the nice rounded ones that would help in your polish load. Some of what's in there will be junk, but a lot of it that's not already round and pretty will soon shape up while cushioning your coarse grinds, and eventually be ready for a polish. I'll see if I can follow up with a photo. (And apologies in advance to my pals on this board who may be tired of my photos...)
Wow - this is great news for me. Thanks, everyone for your responses. I have a problem sometimes with the polish in Stage 4 embedding in cracks and crevices of my "perfectly imperfact" rocks. For some reason, this doesn't happen with the AlOx 500. It doesn't make sense, I know. Even with the rocks that I think are perfectly smooth, the black rocks look a bit grey after the polish stage. So, polish has been the thorn in the rose for me. Hopefully now I can try skipping it more often!
Are you using a thickener? Sorry if you mentioned it and I missed it. I use psyllium fiber (Metamucil). It has the added benefit of creating a slightly doughy gel that takes the grit away with it, rather than leaving it in the cracks and pits. (Picture how bread dough sticks together when you knead it. Obviously a slurry isn't THAT thick, but you get the idea....) I've found that adding a 1/4 tsp. psyllium really helps to not just cushion the load, but makes cleanup easier - the grit rinses away with it better than with anything else I've tried, seen, or heard of.
Thanks for remembering me . I definitely skip the polish stage for most loads in the Lot-O-Tumbler. If you're doing obsidian, though, make sure you have at least 50% highly polished 7-mohs smalls in with it, or the grit doesn't break down well into a polish. Depending on the load and the hardness, 24 - 48 hours is usually sufficient for a 500 grit to have broken down and done the polishing as well. I'd love to see photos! Best wishes, Inga
Use less grit and more ceramics. Doesn't need to be smalls
Ahh - to each his own. I agree on less grit than the instructions call for - I only use a 1/4 tsp of AO 500 on my second (and final) step in the Lot-O, but I don't care for ceramics as much as the quartz/agate aquarium gravel that gives me my smalls. It feels like I get a deeper shine with them (and I just like them!) but sure, ceramics work too.
Thanks for remembering me . I definitely skip the polish stage for most loads in the Lot-O-Tumbler. If you're doing obsidian, though, make sure you have at least 50% highly polished 7-mohs smalls in with it, or the grit doesn't break down well into a polish. Depending on the load and the hardness, 24 - 48 hours is usually sufficient for a 500 grit to have broken down and done the polishing as well. I'd love to see photos! Best wishes, Inga
ingawh said to use 1 tsp of sugarfree Metamucil and 1 tsp bleach (to stop the gas) to create a gel. I have put my rocks in filled the water to the level I will need it took just the rocks out added the grit Metamucil and bleach and tumbled it for a bit to get the gel going then put the rocks in. The gel hasn't allowed the grit get under the layers or cracks. Has worked so far so good. Used the Metamucil in pre polish and polish fine polish so it doesn't slip in and stay in.
I would love to see how this works for you on the labradorite. I'm afraid, even with the Metamucil, labradorite remains a challenge for me, and I would not say I'm satisfied with my efforts to tumble-polish it. The slurry washes away cleanly, but the surface just seems to be prone to the look of those tiny cracks and scratches. Best wishes
Hahaha - I just dump it in and pray all the way! The only time I might pre-mix is if I were going to make up a batch of the pea-soup-thick tripoli polish to keep and re-use indefinitely. I started to do that once years ago, but then found the Lot-O-Tumbler, and now don't do enough rotary polishes to bother with that.
I love your good questions and enthusiasm. Hope you have lots of fun and rewarding polishes ahead of you.
Thank you, only way to learn is ask. Our nursing school motto was "no question is stupid unless it's left unasked" I am in an auora group and when a newbie asks questions that have been asked hundreds of times they get snotty. I try to search before I ask but sometimes you just can't find what you need. I only have 3# barrels, 4 of them, each dedicated to a stage. I had to redo my agate. As hard as those suckers are they have bruises 🙄 I have had rose quartz in 60/90 for almost 2 weeks now. And they still have blemishes. ☹️ Should I move them to 120/220 for a couple weeks. I am trying not to be to anxious but I want these to work out for a specific reason. I just put them back in with the fiber and bleach and am praying.
Kelly
Sometimes you find that the rough rock just has imperfections all the way through, and you may grind it down to nothing, and never find some "perfect" core or stopping place. To help with that, some people pre-shape the rocks a bit on a grinding wheel, and some use a clear filler that hardens in the cracks and pits before they tumble the stone. I guess I'm more OK with letting the rock be whatever it is, and knowing "when to say when" if a particular rock is just not turning out. That can be especially hard in the beginning when you've got your hopes set on a particular stone becoming a "gem."
So back to your question - 2 weeks is actually not a long time for a course grind on a 7 mohs stone, especially in a #3 barrel. The smaller the barrel, the longer the course grind can take because the sheer weight of the stones contributes significantly to the effectiveness of the grit and the grinding process. To put it in perspective, I have a 40 lb barrel that I love to use for most of my rough grinds on stones that are a 6 or 7 mohs (and are not too shatter-y -- I don't put obsidian in there, for example, though I probably could with enough filler....). Even in the 40 lb barrel, it can easily take a month to get a nice shape on the stones, and some stones even go back in couple more times after that until I feel they're really ready to move on. Rose quartz is hard, but it can also have lots of cracks and fault lines that may shatter before you get the shape you're looking for. It may not be anything you're doing "wrong" - it can just be the nature of the rough you have. If you're using plenty of good media, be patient, and realize this is a marathon, not a sprint, and keep going in the course grind a while longer to see if you can get a shape you're pleased with, and reduce more of the blemishes. Check once a week, and if the grit has completely worn down, but the rocks aren't done, recharge with fresh grit and water and keep going. By four weeks, if you're still not sure, I'd say go ahead to the next grind, and see what you get. You can always go back a step later if you want, but when you're starting out, I say there's no point driving yourself crazy waiting for perfection that may never come.
(BTW - My theory is that the sellers of rock tumbling equipment like to say to tumble a week at each stage, because lots of newbies would probably not bother to get started if they knew how long it can really take! )
Hope that's helpful.
About me: I am not a perfectionist, but I AM an experimenter. I'll play by the rules for a while, and then I'll just "play" and see if what I've learned can help me improve the process. It doesn't always work, but when you achieve a breakthrough, it can be really rewarding. I can't wait to see what you come up with. Best wishes
Do you make the slurry up then put it in the tumbler or just put it all in the tumbler and pray. 🙂
Hahaha - I just dump it in and pray all the way! The only time I might pre-mix is if I were going to make up a batch of the pea-soup-thick tripoli polish to keep and re-use indefinitely. I started to do that once years ago, but then found the Lot-O-Tumbler, and now don't do enough rotary polishes to bother with that.
I love your good questions and enthusiasm. Hope you have lots of fun and rewarding polishes ahead of you.
When I have to polish something that does not fit in the vibratory tumbler, I DO use psyllium in the rotary tumbler as well. BUT, since the process has to run for a week or more, there is time for biological action to build up gas because psyllium is a natural fiber. Therefore, I add a couple teaspoons of bleach to the slurry to kill the bio-action. The psyllium does the same job - thickens the slurry to guard against bruising and chipping AND makes the grit want to stay in the slurry, not the pits of the stones. Spraying the stones with the garden hose nozzle, you can see slurry seem to pop out of pits and crevices because the slurry would rather adhere to itself - stick together - than stick on the rock. I recommend using sugar-free Metamucil, or Costco's Kirkland brand of the same thing, if you want to give psyllium a try. Just put up with the nice orange scent. :-) If you have something like that around the house, you can even use the kind with sugar in it - just use a little bit more. In a six pound barrel, a teaspoon of sugar free, and a couple teaspoons with sugar, ought to work, but you may have to experiment. And don't forget the teaspoon or two of bleach. Best wishes.
Thank you. So for a 6# barrel you use 1 tsp sugarfree AND 3 tsp of sugared with bleach? Thank you. Does tumbling take longer with the gel?
Just one or the other (sugared OR sugar free). I edited my post above to make it clearer. I prefer the sugar free, and since the sugar takes up a fair amount of space, a smaller amount when using sugar-free works fine. A little bit of bleach is required with either kind.
I have never found that the fiber slowed down the polish. In my experience, what slows down the polish are things like plastic pellets and fabric scraps used to try and buffer the stones - but they also reduce the contact that is critical for the polishing effect. So I prefer hard, well-polished media, in a nice thick slurry. That allows for both the right amount of buffering, while still providing contact firm enough to impart a shine.
Just as an alternative to the psyllium thickener: I have a friend who reuses his polish slurry indefinitely, and it is as thick as pea soup. He does not add a thicker - it's just lots of cheap old tripoli polish and the build up of ground-up rocks from hundreds of polish cycles. He also uses lots of agate/quartz media, and he gets a brilliant shine - including on obsidian. Tripoli is comparatively cheap, and if you reuse it, only replenishing for what has come away on the stones and gotten rinsed off, its ultimately cheap as dirt to do it this way (in terms of what you spent on polish grit, anyway). I don't use the rotary barrels for polishing often enough to keep a vat of used tripoli-based polish around. If you think you will be polishing in the rotary barrel regularly, you could try his method. You should then skip the psyllium (because it will begin to rot and get stinky, or you have to keep adding bleach - no point if you've used enough tripoli). To try this method get yourself a big tub of tripoli and mix up a slurry that is literally about the consistency of pea soup, then pour it over your polish-ready stones and media. My friend tends to fill his barrels high enough to cover the stones. When done, carefully strain the slurry into a clean, new bucket with a lid, ready to reuse on your next polish batch. Just add more tripoli and/or water as needed to maintain the consistency. My friend does this on an industrial scale - he has over rotary tumblers 50 tumblers going at one time, and gets legendary results. You may choose not to fill your barrels and full as he does - he has a massive motor running the whole operation, but an over-full barrel can be hard on a small tumbler motor. I'll post pics of his set up below...
I read someone was adding Metamucil to make his polish into a suspension gel. I don't know.
You may have seen me mention that recently in this thread, titled "Borax". I wanted to get away from using Borax because I don't really have anywhere to dump my used water than my lawn (I let the slurry settle in a 5 gallon bucket and use a cup to scoop out the water. After a while I let it dry out completely and dump the "brick" into the trash) and I didn't want Borax to kill the lawn.
That said, I was also talking about a vibratory tumbler, not a rotary. I got the idea from ingawh from this post from a few years ago. She uses hand soap and psyllium powder (That's what Metamucil is) along with the polish. I just finished my first batch myself using this method and it worked great. But, I don't know how well this would help in a rotary tumbler. A vibratory tumbler uses very little water. As in, the stones are wet but there is no standing water at all. So the soap and psyllium make a gel-like doughy slurry. In a rotary, I suspect it would just make a frothy, bubbly mess considering the barrel uses much more water. If you look at the bottom of the Borax post, you'll see a video I posted showing what the slurry looks like.
When I have to polish something that does not fit in the vibratory tumbler, I DO use psyllium in the rotary tumbler as well. BUT, since the process has to run for a week or more, there is time for biological action to build up gas because psyllium is a natural fiber. Therefore, I add a couple teaspoons of bleach to the slurry to kill the bio-action. The psyllium does the same job - thickens the slurry to guard against bruising and chipping AND makes the grit want to stay in the slurry, not the pits of the stones. Spraying the stones with the garden hose nozzle, you can see slurry seem to pop out of pits and crevices because the slurry would rather adhere to itself - stick together - than stick on the rock. I recommend using sugar-free Metamucil, or Costco's Kirkland brand of the same thing, if you want to give psyllium a try. Just put up with the nice orange scent. :-) If you have something like that around the house, you can even use the kind with sugar in it - just use a little bit more. In a six pound barrel, about a teaspoon of the sugar-free kind, (or a couple teaspoons of the kind with sugar) ought to work, but you may have to experiment. And don't forget the teaspoon or two of bleach. Best wishes.
Top tip, I know that keeping the lid on can be... challenging. I found some short bungie cords that came in a multi-pack, and just hook one around the barrel to the frame, and it was a revelation!!!
This is what the slurry looked like after 24 hours. Is this about what you'd expect it to look like? It looked a little to foamy to me, but the action still seemed fine and feeling it with my fingers I think it felt fine... but I'm not really sure since this is the first time I've tried your method and pretty much every video on Youtube either uses Borax or sugar.
That looks pretty good. Do you notice that, while the lid may be damp, the dampness is mostly clear water, and the actual grit and slurry stay down in the barrel? That's a good sign that the psyllium is doing its job and the proportions are right. Best wishes, Inga
I see everyone here that says they don't use Borax says they use sugar (if there was another thing said, I didn't see it). I've been using Borax, but wanted to start using something else so I don't have to worry about killing any grass/plants. So I just started using hand soap and psyllium husk powder like ingawh mentions in this thread here. Now... I am literally running my first batch ever in 500 AO using this method, but it's been going for a little under 24 hours and seems to be working just fine. There's a nice slurry going in the Lot-o and I didn't have to really add much water at all. The slurry is almost gel-like in its consistency. When using the Borax, it seemed to soak up the water and I was having a hard time consistently getting the water levels just right.
Can't wait to hear how it worked for you! 😃The gel-like consistency it perfect! At clean up time, the grit stays in the slurry, and the slightly doughy behavior means it pops easily out of any pockets in the stones, too. In my experience. Fingers crossed. 🤞
jamesp. What can I say? I continue to live in awe of your skill and inventiveness. And your dog-with-a-bone determination to figure things out and build on each new improvement in your process - "good enough" is not good enough!
Hats off to you - not every artisan is an artist, but you truly are.
Happy New Year, my friend.
Happy New Year ingawh. Thanks for the compliments and your revolutionary 2 step tumbles. Perhaps mad scientist may fit us better lol.
check this out: The guys that tumble brass bullet casings are doing away with their vibratory tumblers and replacing them with ultrasonic cleaners. The ultrasonic units are way quicker and in most cases turn out a better finish. Ultrasound may work well with brass with cleaning fluid. It may be that vibratory tumblers could be made that will circulate rocks with abrasives at higher vibration rates using sound generators.
This is a 50 watt vibration(sound)generator easily powered by most any stereo. It converts table tops, doors, windows, etc into bass speakers. Even small 5 watt generators powered by an iPad can turn a table top into a large speaker. At 50 watts this one should be able to make vibratory tumbler hopper vibrate when rigidly attached to hopper. It is basically the device that vibrates a bass speaker from 50hz to 300hz. But it is sealed and detached from speaker and often bolted to a chair or the floor to give body felt sound experience. The Lot-o vibrates at 50hz, thinking 100hz to 200hz might be appropriate for finishing rocks at high gentle rates. Imagine a Black Sabbath or Metallica tumbles ha. Use low pitch rock for AO 500 and opera for polish
When you have researched exactly which cuts off of what album, and which soprano signing which aria, I expect you to publish, and win the Nobel Prize in physics.
jamesp. What can I say? I continue to live in awe of your skill and inventiveness. And your dog-with-a-bone determination to figure things out and build on each new improvement in your process - "good enough" is not good enough!
Hats off to you - not every artisan is an artist, but you truly are.
krissykitty , to change/align the weights, the white fans can be rotated by hand quite easily. With one weight known, rotate the other so that it lines up with the known one.
Agreed, but I will also note that the first time I tried this, it actually was a little difficult to force a fan to rotate so as to align - enough that I worried I was going to break it. But it finally did move, and didn't break. You just have to "man-handle" it a bit.
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