qdup1
off to a rocking start
Member since April 2018
Posts: 16
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Post by qdup1 on May 14, 2018 16:17:07 GMT -5
I'll bet this topic has been addressed before, but I am going to ask. After I did my 4th and final polish stage, the rocks, mostly Jasper and a bit of agate are very smooth but also very dull, unless of course they are wet. Is it just that these rocks do not polish to a high gloss? It seems like all the pictures I see of other finished rocks all look very glossy and they look like agates and jasper. Could just be the operator not doing something that the expert tumblers do to get the glossy results. Thanks for any input.
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Post by Drummond Island Rocks on May 14, 2018 16:27:06 GMT -5
I'll bet this topic has been addressed before, but I am going to ask. After I did my 4th and final polish stage, the rocks, mostly Jasper and a bit of agate are very smooth but also very dull, unless of course they are wet. Is it just that these rocks do not polish to a high gloss? It seems like all the pictures I see of other finished rocks all look very glossy and they look like agates and jasper. Could just be the operator not doing something that the expert tumblers do to get the glossy results. Thanks for any input. Agates and jaspers are as good as it gets when it comes to shine. It will be hard to tell you exactly where your process went wrong. Could be a simple as the wrong type of polish or not long enough in polish or could be as complicated as something that happened back in stage 1, 2 or 3. If the first steps are not done correctly there is no way to recover in the polish stage. I would need to hear your entire process from start to finish to be able to offer any advice. Need the following info for each stagerotary or vibratory Barrel size used amount of rock amount of filler - smalls, ceramics, or plastic beads total fill amount (percentage of barrel filled with combination of rock and filler amount of water amount of grit amount of time You mention 4 steps. Quite a few of us are running 5 steps and then sometimes a 6th step of a quick burnish. step 1 - (30 - 80) grit S/C step 2 - (120 - 220) grit S/C step 3 - (500 - 600) can be S/C or A/O - I use A/O step 4 - 1000 A/O step 5 - 14,000 grit A/O Step 6 burnish with Borax or ivory soap flakes Chuck
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Post by aDave on May 15, 2018 2:06:59 GMT -5
Chuck has pretty much hit all of the high points that need to be answered to help you with your lack of a shine at the end of all your stages.
Agates and jaspers should easily polish, so something went wrong somewhere. For me (and like Chuck), I would like to see what different steps you took at all stages and what tumbler you're using. If you could detail what you did with each stage, that will be pretty helpful.
(Seemingly) like you, I use rotary tumblers for everything, but I've never had a batch that came out of the last stage that was not polished.
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qdup1
off to a rocking start
Member since April 2018
Posts: 16
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Post by qdup1 on May 24, 2018 15:31:24 GMT -5
Thank you guys for your help. I know its user error as I am a beginner here. I use a rotary tumbler and am leaning towards trying out a Gy-Roc vibrator unit B model. Sounds like I need to try 5 steps and maybe 6. I didn't know about the burnishing process step. Will do that for sure. My barrel size is 3 lbs and let it run each step for 7 days. I fill the barrel up to about 3/4 full and see that after step 1 the volume shrinks to around 2/3 full. I did add ceramic pieces to the barrels to bring the level up to 3/4 full. I put enough water in until it is almost level with the top of the stones. What does S/C and A/O stand for? Thats about it. I actually have 2 3 lb Thumler's Tumblers. One is a model AR-1 and the other I don't know. It has a different motor that has housing around it. The AR-1 spins have as fast as the other one does. I thought that may have something to do with it. The one that has the higher RPM seems to do a better job.
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Post by grumpybill on May 24, 2018 16:52:44 GMT -5
AO = Aluminum Oxide. SiC = Silicon Carbide. These are the minerals used for most grits and polishes used in rock tumbling.
I have no experience with Thumbler's machines, but it's possible the belt is too loose on your slower one.
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Post by aDave on May 24, 2018 20:13:11 GMT -5
Thank you guys for your help. I know its user error as I am a beginner here. I use a rotary tumbler and am leaning towards trying out a Gy-Roc vibrator unit B model. Sounds like I need to try 5 steps and maybe 6. I didn't know about the burnishing process step. Will do that for sure. My barrel size is 3 lbs and let it run each step for 7 days. I fill the barrel up to about 3/4 full and see that after step 1 the volume shrinks to around 2/3 full. I did add ceramic pieces to the barrels to bring the level up to 3/4 full. I put enough water in until it is almost level with the top of the stones. What does S/C and A/O stand for? Thats about it. I actually have 2 3 lb Thumler's Tumblers. One is a model AR-1 and the other I don't know. It has a different motor that has housing around it. The AR-1 spins have as fast as the other one does. I thought that may have something to do with it. The one that has the higher RPM seems to do a better job. I have just a few thoughts based upon what you provided (listed in no particular order ) : 3/4 full barrel would probably be at the top limit of where you want to be. Good range to shoot for is 2/3 - 3/4. Too full, and you'll potentially inhibit tumbling action. You may be using too much water. Most instructions I've seen want the water added up to the bottom of the top layer of rocks. If you're almost covering all of the rocks, you may also be slowing tumbling. If you're running only 7 days for each step, you may want to readjust. I'm not saying you can't get halfway decent results running such short time periods (I was able to when I first started) but the time limits most tumbler instructions list are just not long enough IMHO. Most here are running far longer time periods at some stages. What makes it even more tough for you is that your barrels don't hold alot of material weight-wise (weight adds to tumbling efficiency), so running the bare minimum to get good results is really going to be an uphill battle. For example, here is what I'm doing at each of my steps. This process works for me, my setup, and what I typically tumble. It should not be taken as gospel, as each tumbler may end up with their own tweaks over time. Keep in mind that I'm using two six pound barrels to run my first stage, and then I'm using four pound tumblers to do all other stages: Coarse Stage (46/70 SiC). I run this stage pretty much 24/7 until rocks are ready to move on to the subsequent stages. Sometimes, this can take weeks, if not months. Not all rocks will finish this step at the same time, so as I remove rocks that are ready, I replace with new rough to top off. The rocks ready to move onto the next stage are saved until I have enough rocks to move to the medium stage. Here, I look for rocks that are fairly smoothed/rounded to move along. With you moving rocks only after 7 days, not much has happened to your rocks and grit could have been captured in pits or other flaws. Smooth rocks are less likely to trap grit, and contamination with trapped grit could be one reason why you didn't acheive a polish at the end. To avoid contamination, inspect and brush out cracks on every single rock. Oh yeah, for you, 60/90 SiC will be fine for your coarse grit, as you don't have enough material in your barrel to break down the larger grit so it works properly. If you decide to perpetually tumble a coarse stage, get far more coarse grit than the other, as you'll be going through lots of it. Cleanouts are done every week, and fresh grit is added. Remember, this stage is really the only stage where you'll be able to shape your rocks. Subsequent stages, in comparison, really don't remove enough material to affect shape - just enough is removed to eliminate scratches from the previous stage. Medium Stage (120/220 SiC). I run this stage for about 7 days, no less. I have found this to be sufficient for my purposes, and there has been no need to readjust. Fine Stage (500 AO). I run this step for two weeks. Some folks will run 500 AO (or SiC) for one week and then a prepolish step of 1000 AO for another week. I'm doing two weeks to try to take advantage of grit breakdown, so I'm still somewhat prepolishing here, as the grit will get smaller over that time. Burnish Stage (Borax Laundry Additive). This is only run for a few hours. I do this before I start my polish stage just to try to help remove/clean any grit. This will not do anything to polish or remove material. Polish Stage (1:14,000 AO). I run this stage for three weeks. I used to run for 1.5 weeks, but I think I see a pretty fair difference by going longer than that. Final Burnish (Borax Laundry Additive). I run this for about 4 hours. This is also a cleaning stage which helps to remove any trace of grit or slurry. It does not have a polishing action in and of itself. You mentioned that you use ceramics to top off. I use plastic pellets at all stages after coarse, and I have plastic that is dedicated for each stage - it is not moved along like you can with ceramics. But, my main point for bringing up ceramics is because I'm wondering if you tumbled them on their own first to knock off the sharp edges. Again, I don't use the stuff, but I think I've seen folks mention tumbling them first to knock off sharp edges to keep from scratching their material. If new/unprepped ceramic can actually scratch up material, that could be another reason for not getting a polish at the end. Lastly, and grumpybill touched on it, if you have one tumbler running half as fast as the other, that could also be an issue. As he stated, check belt tightness and be sure there is no slipping. I am not familiar with the Thumlers, so I can't tell you how many RPMs they should be turning at. I would tend to think however, that the barrel should be at least around 40 RPMs, if not more (just a guess). Hope that helps some. Good luck.
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qdup1
off to a rocking start
Member since April 2018
Posts: 16
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Post by qdup1 on May 24, 2018 22:40:16 GMT -5
Wow !!! What a super nice explanation of the processes involved and so much more in depth detail that I surely need. Great help and I do appreciate all your help. I would have never learned this on my own. I replaced the belt today on the slower one and it seemed to run a little faster. The new belt is much tighter. Not quite as fast as the faster one, but an improvement. I will count the rpm's just for the heck of it.
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qdup1
off to a rocking start
Member since April 2018
Posts: 16
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Post by qdup1 on May 28, 2018 13:40:03 GMT -5
Forgot to ask. For every 3 pounds of rock how much grit should be added and does it vary each stage? Thank you.
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Post by grumpybill on May 28, 2018 14:21:20 GMT -5
Conventional wisdom is 1 Tbsp per pound of stones, all stages in a rotary.
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Post by aDave on May 28, 2018 17:37:02 GMT -5
Conventional wisdom is 1 Tbsp per pound of stones, all stages in a rotary. Unconventionally , I've had pretty decent results by cutting way back on polish. I'm at a bit more for the other stages (about 1.5 level Tbsp), but I was able to use less than half that in the polish stage. I found that Lortone's recommended amount of polish caused way too thick of a slurry, and I followed some advice here to use much less. So far it's working.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,561
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Post by jamesp on May 28, 2018 18:53:47 GMT -5
The Vibrasonic instructions called for overdoses of abrasives. I always used 0ne cup coarse for 14 pounds , 1 cup 220, 1/2 cup 500, 1/2 cup polish in rotary. For years with good results.
16 tablespoons / cup
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Post by grumpybill on May 28, 2018 21:02:33 GMT -5
I found that Lortone's recommended amount of polish caused way too thick of a slurry, and I followed some advice here to use much less. I'm glad I found this forum during my first batch. Otherwise I'd have been following Lortone's recommendations, which I think were written to sell lots of abrasives and polish.
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Post by aDave on May 28, 2018 23:45:15 GMT -5
I found that Lortone's recommended amount of polish caused way too thick of a slurry, and I followed some advice here to use much less. I'm glad I found this forum during my first batch. Otherwise I'd have been following Lortone's recommendations, which I think were written to sell lots of abrasives and polish. Totally agree with your assessment. I am on the low end of what they recommend when it comes to grit amounts. The polish stage is where I really made an adjustment. To be frank, I still might be on the high side of grit usage for the first three stages, but I've been too lazy to test the 1 tbsp formula in comparison to what I'm using now. To the OP, when doing the grit calculation, I'm doing it against the pound capacity of the barrel, and not how much rock is going into the barrel. No need to weigh your rocks for each batch. If you have a three pound barrel, calculate your grit usage on that amount.
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qdup1
off to a rocking start
Member since April 2018
Posts: 16
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Post by qdup1 on May 29, 2018 15:46:27 GMT -5
Thanks again for all your help. I will try conventional wisdom first and see how that goes. I was using 1 rounded Tbsp per pound and will try less for the polish stage.
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qdup1
off to a rocking start
Member since April 2018
Posts: 16
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Post by qdup1 on Jun 11, 2018 16:19:54 GMT -5
Things are looking up. Ran the polish stage for 2 weeks instead of one week and I see a significant difference. Thanks everyone for your advice and wisdom.
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