jamesp
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Post by jamesp on Sept 11, 2014 14:32:10 GMT -5
Pre-shaping scars, nasty. Stuff pre-grinds fast too. This photo not shown earlier, forgot I had pulled this at day 4 of first coarse grind. Was very happy to see the nasty pre-grind marks going away so fast. Ran fast at 60 RPM. And this is several rocks after 5 days in AO 220. To compare. Same mag. I am impressed. These surfaces look smooth for a 220 sand paper finish. Smooth for a 220 tumble surface. And a big improvement over the 4 day coarse grit photo above. Looks like things are moving forward. Today starts AO 600. And this photo I bumped the magnification a bit to max, taking several and picking the best focus. My guess would be that a Lot-o would spank this finish. Let's see what the rotary will do. Will run with more sugar than the 220. Want it to have about a saw lubricant viscosity, like almost mineral oil.
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jamesp
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Post by jamesp on Sept 11, 2014 15:49:26 GMT -5
Oops, next step will be 400, not 600. Thought it was 600, which I strongly preferred. (started 400 Fri. aft.)(16 due wed)(46 to 20 Fri. aft) Captured some of the 220. Will study it thru a loupe and find an image to match it to since I can not do micro photos. It felt smooth when rolled between fingers. Does anyone know if AO polish is 1000 ?
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Post by Drummond Island Rocks on Sept 11, 2014 16:02:04 GMT -5
I only use my A/O 1000 as a pre-polish step when needed. I use two different A/O polishes for my final step and one is one micron (I think this translates to about 14,000 grit) and my super polish is sub-micron in size and probably around 50,000 grit.
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jamesp
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Post by jamesp on Sept 11, 2014 16:21:41 GMT -5
I only use my A/O 1000 as a pre-polish step when needed. I use two different A/O polishes for my final step and one is one micron (I think this translates to about 14,000 grit) and my super polish is sub-micron in size and probably around 50,000 grit. Thanks for that reply Chuck. And the super polish. Can I ask if you use those fine polishes in the rotary ? And Lot-o ? And, don't you think that my skip from AO 400 to AO 1000 is too big of a step ?? Even if a run the 400 for a long time.
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Post by Drummond Island Rocks on Sept 11, 2014 16:43:40 GMT -5
Back in the rotary days I always used rocksheds A/O polish and I think I have heard that it is around 1 micron. Someone can chime in if they have heard otherwise.
running your 400 longer should certainly help with the step from 400 to 1000 since the grit is breaking down over time. If grit goes from 400 to 800 in 24 hours in the loto then I would assume it would go from 400 to 800 in a week in your rotary? I would say after 24-36 hours in your rotary your surface may be at the 400 grit level but after 10-14 days I would think there would be a difference. Good experiment for sure. I am sure others will learn from this thread.
Chuck
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jamesp
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Post by jamesp on Sept 11, 2014 19:08:15 GMT -5
Back in the rotary days I always used rocksheds A/O polish and I think I have heard that it is around 1 micron. Someone can chime in if they have heard otherwise. running your 400 longer should certainly help with the step from 400 to 1000 since the grit is breaking down over time. If grit goes from 400 to 800 in 24 hours in the loto then I would assume it would go from 400 to 800 in a week in your rotary? I would say after 24-36 hours in your rotary your surface may be at the 400 grit level but after 10-14 days I would think there would be a difference. Good experiment for sure. I am sure others will learn from this thread. Chuck So your grit is pretty much powdered in the Lot-o by the time a few days is up. The vibs seem to get the most out of those fine grits in a hurry. I see your point about letting it run longer. I looked for any 220 and found no particles, supposing it broke down to fine particles. Will do some more photos after a few days in 400. Same magnification and put them up close to the 220 photos. Have a hard time seeing the surface texture without cropping on the image. After 400 the camera thing may not be enough magnification. I was surprised Krystee's obsidian was so shiny w/500 grit. It obviously broke down to a smaller grit. Thanks
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Post by nowyo on Sept 11, 2014 22:26:40 GMT -5
Really interesting thread, thanks for keeping it going. Haven't tumbled obsidian in a few years, learning new things here.
Russ
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Post by iant on Sept 12, 2014 1:31:11 GMT -5
Back in the rotary days I always used rocksheds A/O polish and I think I have heard that it is around 1 micron. Someone can chime in if they have heard otherwise. running your 400 longer should certainly help with the step from 400 to 1000 since the grit is breaking down over time. If grit goes from 400 to 800 in 24 hours in the loto then I would assume it would go from 400 to 800 in a week in your rotary? I would say after 24-36 hours in your rotary your surface may be at the 400 grit level but after 10-14 days I would think there would be a difference. Good experiment for sure. I am sure others will learn from this thread. Chuck So your grit is pretty much powdered in the Lot-o by the time a few days is up. The vibs seem to get the most out of those fine grits in a hurry. I see your point about letting it run longer. I looked for any 220 and found no particles, supposing it broke down to fine particles. Will do some more photos after a few days in 400. Same magnification and put them up close to the 220 photos. Have a hard time seeing the surface texture without cropping on the image. After 400 the camera thing may not be enough magnification. I was surprised Krystee's obsidian was so shiny w/500 grit. It obviously broke down to a smaller grit. Thanks I'm enjoying following this too. I think it would be very hard to determine any difference in smoothness without having a rock from each of your own and Krystee's tumbles at the 400/500 stage in hand. Photography doesn't always give the whole picture -quality, light conditions etc vary hugely. There are so many variables. I would proceed with your plan and see how things work out. Good luck
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Fossilman
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Post by Fossilman on Sept 12, 2014 8:55:11 GMT -5
Nice way to expose your tumbled rocks...Thanks for the tip...
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jamesp
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Post by jamesp on Sept 12, 2014 8:56:31 GMT -5
[/quote] I think it would be very hard to determine any difference in smoothness without having a rock from each of your own and Krystee's tumbles at the 400/500 stage in hand. Photography doesn't always give the whole picture -quality, light conditions etc vary hugely. There are so many variables. I would proceed with your plan and see how things work out. Good luck[/quote]
I wish I had a shine at 500 stage Iant. Krystee's obsidian already shiny at 500 !
I have done another 'fast' tumble with a load of coral in the finishing stage. I remember using 220 AO , 400 AO, 600 AO and polish AO and had a fine polished finish. Sugar added in all but 220. In about 10 days total. I remember the stones had a fine polish in polish stage after 24 hours, finish polish at 48 hours(by my standards).
So, since the grit salesman left me with AO 46,150,220,400,600(which I used up) I have these on hand. In watching the obsidian grind so fast I am thinking that 2 days in 220 400 600 800 1000 and then 1 micron polish each may give good finish. That would be a 6 step finish in 12 days. The AO is inexpensive...and should cut obsidian very fast.
So I will pull some obsidian at 24 hours and 48 hours in 400 AO and see if a 400 finish has already occurred. And keep pulling and checking till the surface has little improvement. I am hoping that I can change grit every 24-48 hours for obsidian if using so many grades.
I think a cab machine has many grit steps, so why not use the same approach in tumbling.
Glass is another subject, actually a b-itch. I want soft glass to use as filler glass. The reason is that in rotaries the harder material 'usually' gets the shine, not the softer materials. It may not make a difference but that's what I want to do. There is basically 9 types of glass. The softest is borosilicate glass that is used in lenses. Expensive. Obsidian is considered a soft glass. The blue glass I am using for filler is very hard, I have tried tumbling it and it takes forever to coarse grind. I found a pile of 3/8" glass on the side of the road that I assume was tempered table top glass, it tumbled very fast. Incredibly fast. I will post photos of that stuff. And a bucket of 1/8" tempered glass that broke into thousands of pieces w/one hammer blow. Easy filler. Researching 'hardness of different glass' is a challenge. A complicated subject. Guessing that tempered(heated a certain way) is soft. And it breaks into smalls easy. But still researching. And I want to use pre-coarse tumbled soft glass for all finishing stages. My filler in this tumble is running low, it gets eaten away, and I do not have any pre-rounded glass to add for polish step. So went heavy on the sugar. The obsidian wore fast too, all reducing the level of fullness in the barrel too. Need to keep that barrel at least 3/4.
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Post by iant on Sept 12, 2014 12:00:21 GMT -5
Good plan. Looking forward to the next stage pics!
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jamesp
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Post by jamesp on Sept 12, 2014 12:51:13 GMT -5
After 18 hours in 400 AO from 220 AO. All same magnification. Marked improvement. 220 AO: After 18 hours in 400 AO -Another- 220 AO: After 18 hours in 400 AO -Another- 220 AO: 18 hours
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Deleted
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Post by Deleted on Sept 12, 2014 17:37:51 GMT -5
very nice series of images. Well done.
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jamesp
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Post by jamesp on Sept 14, 2014 15:50:14 GMT -5
About to need higher magnification at this point. I think zero improvement from 18 to 66 hours in AO 400. From what I have seen I could have run 220 for 18 hours, 400 for 18 hours, 800 for 18 hours, 1000 for 18 and 4000 for 18 and have polished obsidian. Seems that the finer the grit the quicker it finishes. Judging from 220 and 400. I do not think the rotary tumbler can break up and use one grit grade like a vib. But it seems to respond well to many grade steps, and quickly to each step. Maybe shorter intervals than posted above. Dammit AO 400 after 18 hours AO 400 after 66 hours
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Post by pghram on Sept 15, 2014 9:53:20 GMT -5
Very educational, thanks!
Rich
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jamesp
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Post by jamesp on Sept 15, 2014 11:04:42 GMT -5
Removed 400 and went straight to AO 1 micron polish to see if it will do the polish. 4 micron on order, so I skipped that step. It should not polish. Maybe it will surprise. Unlike bright coral, the obsidian turns the water grey. The 400 turned it grey, meaning a lot of material was removed. Am not used to such a soft material. Photos of results in a day or two. Noticed Rock shed sells AO 500, AO 1000 and AO 1 micron polish. Bet that will do the trick. That is what is on order.
The obsidian and the glass filler reduced in size a lot. Glass filler added untumbled during coarse grind, pre-tumbled in 220 and 400 steps. Running 15 pound barrel full of soft glass in coarse using AO 46 sand blast grit for future obsidian filler. Should take about 4 days. Obsidian and filler down to 5/8, out of pre-tumbled filler, so went heavy on sugar at 4 cups/10 pounds making SAE 30 weight oil consistency. When 400 load was poured out it had slump(thick). Very slick. Slurry battleship grey, maybe darker. 400 completely converted to thin(smooth to the touch) mud when spread on black plastic mortar mixing pan. Zero frosted areas when clean and dried. Sheen obsidian freaky pretty when wet. hooked
Sugar purchased at Sam' Club in 50 pound bag.
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Post by nowyo on Sept 15, 2014 23:53:07 GMT -5
Yeah, obsidian is a different animal. haven't done any in a few years, This is making me want to run a batch again. Thanks for the photos of your progress.
Russ
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jamesp
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Post by jamesp on Sept 16, 2014 6:14:52 GMT -5
Yeah, obsidian is a different animal. haven't done any in a few years, This is making me want to run a batch again. Thanks for the photos of your progress. Russ My target is a fast and cheap batch Russ. Using 35% small glass filler, 3 cups sugar/10 pounds rock and filler, and all aluminum oxide except perhaps SiC for coarse. For apache tears or pre-ground obsidian, 7-10 days in coarse, 3 days AO 220, 2 days AO 500, 2 days AO 1000 and 2 days 1 micron AO polish. 15-20 days. Cutting all or some of those times in half may be doable since there is 5 grit steps, especially the fine grit steps.
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jamesp
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Post by jamesp on Sept 16, 2014 11:02:40 GMT -5
Skipped AO 1000(on order). Went from AO 400 to 1 micron polish. Light reflection tells the story well. After 5 days in AO 400, only top of photo in focus(near white mark), stone nicely sanded, zero reflection: Exact same lamp angle as above. Notice pits in glare. Maybe prolonged 1 micron will remove them. But that takes time. After 18 hours in AO 1 micron: Chuck mentioned 50,000 super fine micro polish. Will be ordering some. Where do you get that Chuck ? (if you read this, will PM you) Will continue AO 1 micron and post progress till AO 1000 arrives. Maybe it will get the pits out. May require clean-out and fresh AO 1 micron. Will use glare to show results since camera has lack of magnification at this point.
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Post by Drummond Island Rocks on Sept 16, 2014 11:31:04 GMT -5
PM sent
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