schnur07
off to a rocking start
Member since June 2016
Posts: 12
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Post by schnur07 on Jul 13, 2018 11:18:52 GMT -5
My daughter and I just finished our first batch and were disappointed with the final outcome. Our rocks are on the left compared to some purchased ones on the right. Obviously we didn't get a nice final polish on these for some reason. That's where I need some help. So here's the story: We used grit purchased from Polly Plastics. 60 grit, 180/220, 500, and then a final polish with 1200 aluminum oxide. All grits were done for 1 week. After the third polish I tumbled for a few hours with a little bit of oxiclean laundry detergent to wash away any of the remaining grit. We're using the dual 3 lb tumbler from Harbor Freight if that matters. I don't have dedicated barrels for each grit. I'd be curious about what may have gone wrong and what to do now. Do they just need another final polish or do they need to go back to the third step?
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Post by grumpybill on Jul 13, 2018 13:15:25 GMT -5
Most people here would consider 1200 AO to be a pre-polish, not a polish. True AO polish is on the order of 14,000.
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Post by Drummond Island Rocks on Jul 13, 2018 13:24:04 GMT -5
Welcome to RTH. While there are several factors that can cause a lack of shine I will just start with a couple. The first thing would be that I consider 1200 aluminum oxide to be pre-polish not polish. The Aluminum oxide polish most of us are using is equivalent to about 14,000 grit. So adding that step may help some. The next thing is the one week per grit comment. The very first stage of 60 grit normally goes from one week up to 16 weeks. One week will give you the results you got which still have pits, fractures and semi rough edges. If you had repeated stage one several weeks in a row then each week adding new 60 grit then the imperfections would have gotten smaller until finally gone. How long to keep that process going is a personal preference depending on what you are looking for in the final product. The final polish stage in rotary can also benefit from running a bit longer like 10-14 days. My only other advice is to make sure your are thoroughly cleaning the rocks and barrels between stages. Any grit from stage one that hides in the cracks and pits can come loose in the next stages and cause havoc. Glad to hear you and your daughter picked rock tumbling for a hobby. A great place to shop for grits, polishes and rough rocks for tumbling is www.therockshed.comChuck
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schnur07
off to a rocking start
Member since June 2016
Posts: 12
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Post by schnur07 on Jul 13, 2018 15:05:05 GMT -5
Thanks for the replies! So you would go from 1200 grit directly to 14,000? That seems like a big jump. At this point, since we're just starting we're not as concerned about some of the pitting, etc - don't have the patience yet to tumble for 4 months. But we would like to get to a final polished stage that looks like their wet. So I'll try a final polish with a finer grit and see what happens. We talked to a rock guy at our farmer's market and he uses White King laundry softener for his final polish. He says it's a lot cheaper and does as good or better of a job. Any thoughts on that?
My daughter is 12 and loves looking for rocks. We live in Oregon and find a lot along the Willamette River. Tomorrow we're going to look on the South Santiam R near Sweet Home and see what we can find.
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schnur07
off to a rocking start
Member since June 2016
Posts: 12
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Post by schnur07 on Jul 13, 2018 15:13:32 GMT -5
So which grit from the rockshed website do you use? Does it matter if you use silicon carbide vs aluminum oxide? Can you go to a coarser grit than 60 to start with if you want to shape them quicker?
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Post by Drummond Island Rocks on Jul 13, 2018 15:24:17 GMT -5
12 years old is a great age to get started. My son got me started into this when he was 11 or 12 (about six years ago). Yes the 14,000 is the common next step after 1200 and no it is not too big of a step. I will not go as far as telling you that you got bad advise at the farmers market but I have never heard of that before. I use borax powder soap after my 14,000 polish run. That step is called burnishing in tumbler lingo. It is really more of a final wash. Just a heads up that Borax is toxic to plants so some folks use dreft instead.
I understand not wanting to go longer in stage on at first but the possibility of trapping grit in voids would be an ongoing issue.
Chuck
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Post by Drummond Island Rocks on Jul 13, 2018 15:28:57 GMT -5
So which grit from the rockshed website do you use? Does it matter if you use silicon carbide vs aluminum oxide? Can you go to a coarser grit than 60 to start with if you want to shape them quicker? I do not recommend going lower then 60 grit in a 3 pound barrel. A 3 pound barrel is just not aggressive enough to break down lower grits. A standard grit progression would be as follows. 1) 60/90 or 80 silicon carbide 2) 120/220 or straight 220 silicon carbide 3) 500 aluminum oxide 4) 1000 aluminum oxide 5) aluminum oxide polish (14,000) 6) borax or dreft soap burnish Of course the next step is using the proper amount of rocks, grit and water to suit the barrel capacity. Chuck
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shadyatbest
off to a rocking start
Member since November 2016
Posts: 23
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Post by shadyatbest on Jul 28, 2018 17:30:46 GMT -5
Schnur07 I originally found this site because i had the exact same problem. It's all about time. 1 week is not enough time for the polishing phase and most likely not enough time for any other phase. I doubt that there is anything out there that can be done from start to finish in 4 weeks like the harbor freight instructions imply.
I was able to get a great shine after i stopped keeping talk of time. I would let the tumbler run and forget about it. I think i ran it on the final phase for 2-3 months.
Good luck
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Post by TheRock on Aug 1, 2018 2:43:37 GMT -5
Spending more time in the First Stages 80 grit and 220 grit will pay big dividends on your finished rocks and may get rid of many crevices that can pass on contamination between stages. You can then make up or reduce the time by making the investment of purchasing a Vibe like a LOT O. It will reduce your time in the final 3 stages of 500 Grit 1000 pre polish and 14000 polish stage which is about 3 days each for these final 3 stages. A vibe is way faster in the 500 - Polish Stages. Good Luck ~Duke
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rockcat11
starting to spend too much on rocks
Member since August 2017
Posts: 176
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Post by rockcat11 on Aug 4, 2018 15:39:50 GMT -5
I concour one week is not enough. I typically do one month or more depending on what it is I am tumbling. Also, your rocks have lots of pits that can hide tiny little bits of grit in them.
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blade069
off to a rocking start
Member since December 2020
Posts: 1
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Post by blade069 on Dec 7, 2020 8:39:36 GMT -5
Where do I get 14000 grit polish?
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gatorflash1
spending too much on rocks
Active in Delaware Mineralogical Society, Cabchon Grinding and Polishing, 2 Thumlers B's and a UV-18
Member since October 2018
Posts: 375
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Post by gatorflash1 on Dec 7, 2020 8:51:55 GMT -5
So which grit from the rockshed website do you use? Does it matter if you use silicon carbide vs aluminum oxide? Can you go to a coarser grit than 60 to start with if you want to shape them quicker? I do not recommend going lower then 60 grit in a 3 pound barrel. A 3 pound barrel is just not aggressive enough to break down lower grits. A standard grit progression would be as follows. 1) 60/90 or 80 silicon carbide 2) 120/220 or straight 220 silicon carbide 3) 500 aluminum oxide 4) 1000 aluminum oxide 5) aluminum oxide polish (14,000) 6) borax or dreft soap burnish Of course the next step is using the proper amount of rocks, grit and water to suit the barrel capacity. Chuck Chuck hit's the mark. The only thing he forgot was the timing at each stage and what rocks you should be working on as a newbie. My suggestion is to get this great book which I sent to my granddaughters when they expressed an interest in rock tumbling after seeing mine. As a gift I bought them tumblers, rocks, grit, polish, and most importantly this book to read before starting the tumbling process. They all ended up with some beautiful shiny tumbles. rocktumbler.com/book.shtml I usually tumble rocks until they are smooth and well shaped. This can take several weeks at stage 1 which probably does 95% of the work. There is a great deal more to learn about tumbling and I'll let you read this good reference book about all the variables in rock tumbling and how to address each one to create some great tumbled rocks. Good luck, be patient!
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Post by joshuamcduffie on Dec 7, 2020 8:54:59 GMT -5
Where do I get 14000 grit polish? Typically, polish isn't measured or called "grit" but it is measured in microns. I've bought from Kingsley North, Johnson Brothers Lapidary, Minnesota Lapidary Supply, Stone Age Industries, and The Rock Shed. All sell what you need. I like "TXP" from Minnesota Lapidary Supply, but Kingsley North sells one called "Micro Alumina" which is a 1-3 micron particle sized polish. Good luck and happy polishing!
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Post by Drummond Island Rocks on Dec 7, 2020 10:01:03 GMT -5
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electrocutus
spending too much on rocks
Member since October 2020
Posts: 333
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Post by electrocutus on Dec 8, 2020 10:59:26 GMT -5
I concour one week is not enough. I typically do one month or more depending on what it is I am tumbling. Also, your rocks have lots of pits that can hide tiny little bits of grit in them. Is there a rule of thumb or guideline about how often to add more grit/polish to an ongoing stage when tumbling it for a long time? For example, in the first and second stage coarse grits, if I run each one for several weeks, should I be adding more grit after each week? Do I just add grit to the slurry and keep going, or do I wash everything and start a new coarse grit tumble? how about for the polishing stage? If I want to run polishing for 2-4 weeks, do I need to add/replace the polish partway through? I realize now that I didn't run some stages long enugh in my first few batches, so I'm taking notes and learning! :-) Thanks!
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Post by Mel on Dec 13, 2020 20:37:34 GMT -5
I concour one week is not enough. I typically do one month or more depending on what it is I am tumbling. Also, your rocks have lots of pits that can hide tiny little bits of grit in them. Is there a rule of thumb or guideline about how often to add more grit/polish to an ongoing stage when tumbling it for a long time? For example, in the first and second stage coarse grits, if I run each one for several weeks, should I be adding more grit after each week? Do I just add grit to the slurry and keep going, or do I wash everything and start a new coarse grit tumble? how about for the polishing stage? If I want to run polishing for 2-4 weeks, do I need to add/replace the polish partway through? I realize now that I didn't run some stages long enugh in my first few batches, so I'm taking notes and learning! :-) Thanks! Totally up to your own personal choice. I do whatever I feel like based on results and my time. I try to reuse stage 1 slurry (strain it to get rid of the stone particles) until I'm ready for stage 2 with the same load. Fresh grit is added every week. For stage 2/3/4, I usually fully dump everything, evaluate and set back up 100% fresh. Eventually all the stones will catch up to the same stage of progress.
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