ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Nov 9, 2021 23:14:02 GMT -5
Who has the secret to tumbling Howlite? I haven't tumbled it before, but when I pulled them out, I must admit I was disappointed. I didn't even use just my old two-step, I added an extra step, but couldn't get a real shine - or is that just how howlite rolls? I found a rough stone had broken and was probably buggering things up a bit, but even so, I had hoped for more.... I can go back a step and do a bit of re-smoothing, then I want to take another run at getting a clearer shine. What polishes has anyone tried that might coax a little more out this stone? Any other tricks-of-the-trade you have to share would be greatly appreciated. Thanks, Team!
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ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Nov 9, 2021 23:37:08 GMT -5
Update: A little time to dry out more after the long tumble, plus a bit of hand-burnishing, does seem to help...
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Post by stephan on Nov 10, 2021 0:09:14 GMT -5
I’m not a tumbler, but it’s pretty soft stuff, which often (but not always) means a mirror shine is difficult to impossible.
Haven’t cabbed this either, so no experience to offer. The pictures do suggest a pretty good shine, though.
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ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Nov 10, 2021 1:25:44 GMT -5
Thanks, Stephen. Yes, it is a softer stone than I've had luck with before, so perhaps this is good enough. I was thinking it was closer to sodalite in hardness, but I guess it's softer - at only a 3.5. And I have learned that some rocks do need drying time to get their full shine to show up. Best wishes
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Post by rmf on Nov 10, 2021 7:04:34 GMT -5
I once had problems tumbling a stone that had both soft spots and hard spots. My solution was to add pieces of indoor outdoor carpet cut up in addition to the plastic pellets for cushioning. That worked. Have never tried howlite since it is soft and white. Typically I have found white stones sell poorly. However yours above appear to have an acceptable polish.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,560
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Post by jamesp on Nov 10, 2021 8:30:06 GMT -5
I'll cheer you on ! The only suggestion I can give is a thicker slurry. The Asian folks have the secrets of tumbling soft stones. The challenge is in good hands.
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saxplayer
fully equipped rock polisher
Member since March 2018
Posts: 1,327
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Post by saxplayer on Nov 10, 2021 10:06:56 GMT -5
You can shine it up but it won’t shine like agate since it’s so soft. It’s just the same recipe as per obsidian. Baby it as you have your obsidian in the past. I suspect the shine you get is probably as good as it will get! You know your stuff
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Post by hummingbirdstones on Nov 10, 2021 10:22:13 GMT -5
That one you hand burnished looks pretty shiny to me.
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ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Nov 11, 2021 0:16:34 GMT -5
I'll cheer you on ! The only suggestion I can give is a thicker slurry. The Asian folks have the secrets of tumbling soft stones. The challenge is in good hands. Thanks for the pep-talk! I'll keep experimenting. I actually did have the slurry super nice and thick, with more more actual slurry than usual, and given body with plenty of my old standby, Metamucil. There was a nice smooth rolling action, yet there are more chips than I'd like to see. If the answer is plastic pellets, I just can't go there! I irrationally hate those things! I was thinking about trying the little 2 mm ceramics micro-beads - has anyone tried those? I'll have to keep working at it like I did with obsidian, basalt and porcelanite. Just hoped someone might know if any particular polish or other trick worked better for howlite than others. The other thing I'm working on is getting the feel for using more or less media, so as not to impede shaping, but still protect delicate rocks correctly throughout the process. Anyway, thanks for weighing in, my friend. Nice to hear from you.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,560
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Post by jamesp on Nov 11, 2021 4:25:07 GMT -5
Good to see you tackling the tough challenges again ingawh. The secret to tumbling soft stones from start to finish may just be the vibe. Add also abrasive hardness relative to the soft stones(and media used) and slurry thickness. Abrasives: Relative abrasive hardness has to be an influence. Take it to the extreme, Mohs 9 alum ox being used on a 100% batch of Mohs 2 soapstone will never break down to finer AO. Add say 50% Mohs 7 pea gravel or ceramic media to soft stones and it's a different game, the media will assist breaking down the AO. So 50 to 70 percent hard media is probably the way to go with AO on soft stones unless using softer abrasives like glass powders, diatomaceous earth, iron oxide powders, etc. Vibe: As far as the vibe is concerned I know that the oversea folks use variable amplitude/frequency vibes to tumble/polish soft stones. So the motor is variable speed and the counter-weights are adjustable. Take it to the extreme - the Lot-O's intended vibration rate(frequency) is 50 vibes/sec or 3000 vibes/minute due to a 3000 rpm off-balanced motor. If the frequency stays the same but you double the amplitude or from 1mm to 2mm of each vibe cycle travel the acceleration rates increase exponentially. Increase the acceleration and the impact forces also rise exponentially. If the vibration travel could be increased from 1mm to say 6mm and maintain 3000 vibes per minute the vibe would likely damage hardened ball bearings, shatter ceramic media, and about destroy any material put in the hopper. Most industrial vibes have a readout displaying real time frequency and amplitude. Very simple. If tumbling/polishing aluminum you go with soft media and low amplitude. To shot peen or harden steel surfaces you go with both elevated amplitude and frequency since you want to beat the crap out of the surface of the steel lol. So a fixed amplitude/frequency vibe is just what it is. There is not much of an adjustment on the Lot-O to alter these parameters. Take a Vibrasonic lapidary vibe, it is a constant frequency vibe (3450/min) but the counter weights can be adjusted from a very low amplitude to a high amplitude . Because of the built in springs the optimum amplitude for an 8 pound hopper can be matched to the optimum amplitude for a 50 pound hopper by simply varying the counterweights. I know this, on a scale of 1 to 5 off-balance I set the sonic to 5 with a 14 pound hopper full of glass and it shattered it. It was like filling a 1 gallon paint can with tumbles and placing it into a paint shaker machine with about a 100mm amplitude and fairly high frequency. Granted the paint shaker is a gross example but the same damaging forces occur within our little vibes. Don't be surprised if even the gentle Lot-O is too violent for Mohs 3-4-5 stones. Many attempts have been made to get a high polish on softies on this forum. So that is my opinion and you know what folks say about opinions lol. I wish you luck !
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,560
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Post by jamesp on Nov 11, 2021 4:30:21 GMT -5
Actually looking closer at your Howlite it appears to have a fine polish. It looks like you completed your goal. Congrats !
I forgot to add - when shot peening the surface of steel they often use 7 gram/cc density super tough/heavy Zirconium media, when polishing a softer metal they may use our typical alum ox ceramic media at a lighter 3.8 gram/cc. In the metal finishing industry the various ceramic medias can be fused 100-200-400,,,polish. The media also serves as the abrasive in most cases but powdered abrasives are also used. High density Zirconium media can roll edges and make impact dents in say softer aluminum.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,560
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Post by jamesp on Nov 11, 2021 4:43:27 GMT -5
Lol, please excuse the rant.
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RedWingTumbler
having dreams about rocks
Member since April 2021
Posts: 65
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Post by RedWingTumbler on Nov 11, 2021 8:37:08 GMT -5
I'll cheer you on ! The only suggestion I can give is a thicker slurry. The Asian folks have the secrets of tumbling soft stones. The challenge is in good hands. Thanks for the pep-talk! I'll keep experimenting. I actually did have the slurry super nice and thick, with more more actual slurry than usual, and given body with plenty of my old standby, Metamucil. There was a nice smooth rolling action, yet there are more chips than I'd like to see. If the answer is plastic pellets, I just can't go there! I irrationally hate those things! I was thinking about trying the little 2 mm ceramics micro-beads - has anyone tried those? I'll have to keep working at it like I did with obsidian, basalt and porcelanite. Just hoped someone might know if any particular polish or other trick worked better for howlite than others. The other thing I'm working on is getting the feel for using more or less media, so as not to impede shaping, but still protect delicate rocks correctly throughout the process. Anyway, thanks for weighing in, my friend. Nice to hear from you. Your howlite looks pretty shiny to me! Regarding the beads, don't waste your money. I got two bags of them by accident (I had ordered 6mm & got 2mm), and they are a pain. They bounce and roll everywhere & fall through the holes in the colander. They are scattered all over my garage floor. If you get a crack or pit in a rock, they will lodge in there & can be very difficult to dislodge. I can't see that they work any better than my small oblong ceramic media. If I were you, I'd try using 60-75% small ceramics, so your rocks are swimming in them. Good luck, but I think you already did a great job.
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rrod
having dreams about rocks
Member since December 2020
Posts: 72
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Post by rrod on Nov 11, 2021 9:24:27 GMT -5
More like "humblebragged by howlite" I get worse shine on agates!
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ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Nov 11, 2021 11:19:28 GMT -5
More like "humblebragged by howlite" I get worse shine on agates! That's the nicest back-handed complement I ever got!
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ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Nov 11, 2021 11:20:43 GMT -5
Your howlite looks pretty shiny to me! Regarding the beads, don't waste your money. I got two bags of them by accident (I had ordered 6mm & got 2mm), and they are a pain. They bounce and roll everywhere & fall through the holes in the colander. They are scattered all over my garage floor. If you get a crack or pit in a rock, they will lodge in there & can be very difficult to dislodge. I can't see that they work any better than my small oblong ceramic media. If I were you, I'd try using 60-75% small ceramics, so your rocks are swimming in them. Good luck, but I think you already did a great job. [/quote] Thanks so much for the kind words and the tip - I'll skip the beads.
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ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Nov 11, 2021 11:23:20 GMT -5
Lol, please excuse the rant. You kidding?!? Your "rants" are filled with great info. I used my regular media in good proportion, but I also had some softer picture jasper in there with it. I think I'll run it again with just the howlite and buckets of media in my trusty AO 500. Wish me luck.
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Post by Pat on Nov 11, 2021 15:27:12 GMT -5
Not a tumbler, but a matte finish is lovely! Everything doesn’t have to be shiny.
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Post by Rockindad on Nov 11, 2021 18:04:15 GMT -5
ingawh we did some Magnesite a couple of years ago and it looks almost identical to Howlite, apparently it is also confused by sellers as well. We were pretty happy with the results, though we were not expecting much as it still felt grainy pretty far along in the process. forum.rocktumblinghobby.com/thread/88320/magnesite
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ingawh
starting to spend too much on rocks
The rock wants to shine, I just help it get there
Member since February 2011
Posts: 194
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Post by ingawh on Nov 11, 2021 18:40:49 GMT -5
ingawh we did some Magnesite a couple of years ago and it looks almost identical to Howlite, apparently it is also confused by sellers as well. We were pretty happy with the results, though we were not expecting much as it still felt grainy pretty far along in the process. forum.rocktumblinghobby.com/thread/88320/magnesite Wow - gorgeous shine! I'm inspired! Looks like Magnesite is slightly harder material (4.5ish) compared to howlite (3.5), though I guess I couldn't swear what I have isn't magnesite (got it from Shawn at The Rock Shed). I Love the shaping you got! I'm inspired to go back a step and try for better shaping, then take another run at a final polish. Wish me luck...
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