Post by Bob on Aug 11, 2020 11:21:26 GMT -5
It's time for me to stop just reading and participate and help others too. I rotary tumble only, and have 134lbs going 24/7. Barrels: 1 x 40lb, 2 x 20lb steel barrels; 3 x 12lb, 3 x 6lb rubber barrels. All Lortone. It's been fun to see the interest in large rocks. That is my primary interest. A rock smaller than lemon size I consider small. I tumble a lot of rocks baseball, grapefruit, canteloupe size, and even larger. I think the largest so far is a piece of psilomelane from the CA desert that weighs over 20lbs.
My sequence: 50-60 grit as long as it takes, which for large rocks can take over a year at times. 80 for a week, ditto on 220, ditto on 600, ditto on 1,000 all SC. Then 1st week alum ox, then 2nd week alum ox using separate polish and pellets, then burnish with soap for 3 to 10 hours.
As to the 1,000, I tested it some years ago to see if it improved some rocks in polish. It did. So rather than trying to figure out which they were I just run them all through 1,000 and the results are fantastic. It's expensive, but very little is actually used because by the time the rocks are ready for 1,000, they are practically perfect anyway no never have to repeat that stage.
I tumble to perfection getting rid of all crevices and dings. For fractures that aren't ground out I use Opticon.
I also tumble a lot of colorful granite from Lake Superior, basalts and other rocks that don't polish to a shine. For these, I do last stage in 1,200 or 1,500 SC and end up with a gorgeous satiny finish. It can be left as is or sealed and made much more colorful with a Dupont product made for doing that.
My results really started taking off when I started ignoring a lot of the conventional wisdom and what is published in books and starting thinking fresh about the impact physics of what is actually happening inside the barrels. So I slowed down RPMs of some, experimented for ideal results. Unlike what the books say, I found cleaning the rocks between stages and using clean water and cleaning the barrels counterproductive. When I stopped doing those things results suddenly improved.
But to go into polish I maintain strict hygiene and go to great lengths to avoid contamination. I reuse my polish over and over and have not seen any decrease in results. Some is in it's 3rd year.
Got started in this in 2014 at suggestion of friend to help me get over terrible divorce which was starting then after 28 years of marriage. It has really helped and I'm hooked. Not into cabbing or anything like that. I keep it simple. To me half the fun is finding stuff outdoors and giving it a try. May over half the fun actually.
Just got back from northern NM and found some neat stuff on slopes of Cerro Pedernal. Had a tumbler running off AC power in back of my 4Runner on the trip in the final stages of polish for the contest. That lavic jasper has about driven me nuts!
Have been experimenting with tumbling some British Columbian nephrite--strange stuff to be sure. Have some in 1,000 now and so far so good.
Have been to China 7 times in last 2 years dating my--as of 2 weeks ago my wife--and have seen some amazing material there along the Yangtze River. Brought back a lot of agates from there and am tumbling them now. Now enough done to be sure how will turn out. A lot of internal fractures in many of them annoy me. The Chinese abhor polished rocks like we like. They think they look cheap and trashy like plastic. They prefer only natural satiny finish that occurs in nature.
Under a disguise to hide that I wasn't a foreigner, I was recently allowed to see a family Yangtze River agate mining operation east of Wuhan. I saw a vibratory tumbler that was frightening. I estimate it held about a ton and it was mounted on a concrete pillar into the earth. It still shock the ground for 30' in all directions. Employees maintaining this beast had to wear ear protection and I could not talk to my friends even though I was 100' away from it it was so loud. I got up higher and saw what was in it and it like a boiling cauldron from Hell itself. What a tumbler!
Perhaps my post intro will trigger some curiosity about this or that and I look forward to making some new friends.
Thanks to all for the information shared!
Bob in Stillwater, OK
My sequence: 50-60 grit as long as it takes, which for large rocks can take over a year at times. 80 for a week, ditto on 220, ditto on 600, ditto on 1,000 all SC. Then 1st week alum ox, then 2nd week alum ox using separate polish and pellets, then burnish with soap for 3 to 10 hours.
As to the 1,000, I tested it some years ago to see if it improved some rocks in polish. It did. So rather than trying to figure out which they were I just run them all through 1,000 and the results are fantastic. It's expensive, but very little is actually used because by the time the rocks are ready for 1,000, they are practically perfect anyway no never have to repeat that stage.
I tumble to perfection getting rid of all crevices and dings. For fractures that aren't ground out I use Opticon.
I also tumble a lot of colorful granite from Lake Superior, basalts and other rocks that don't polish to a shine. For these, I do last stage in 1,200 or 1,500 SC and end up with a gorgeous satiny finish. It can be left as is or sealed and made much more colorful with a Dupont product made for doing that.
My results really started taking off when I started ignoring a lot of the conventional wisdom and what is published in books and starting thinking fresh about the impact physics of what is actually happening inside the barrels. So I slowed down RPMs of some, experimented for ideal results. Unlike what the books say, I found cleaning the rocks between stages and using clean water and cleaning the barrels counterproductive. When I stopped doing those things results suddenly improved.
But to go into polish I maintain strict hygiene and go to great lengths to avoid contamination. I reuse my polish over and over and have not seen any decrease in results. Some is in it's 3rd year.
Got started in this in 2014 at suggestion of friend to help me get over terrible divorce which was starting then after 28 years of marriage. It has really helped and I'm hooked. Not into cabbing or anything like that. I keep it simple. To me half the fun is finding stuff outdoors and giving it a try. May over half the fun actually.
Just got back from northern NM and found some neat stuff on slopes of Cerro Pedernal. Had a tumbler running off AC power in back of my 4Runner on the trip in the final stages of polish for the contest. That lavic jasper has about driven me nuts!
Have been experimenting with tumbling some British Columbian nephrite--strange stuff to be sure. Have some in 1,000 now and so far so good.
Have been to China 7 times in last 2 years dating my--as of 2 weeks ago my wife--and have seen some amazing material there along the Yangtze River. Brought back a lot of agates from there and am tumbling them now. Now enough done to be sure how will turn out. A lot of internal fractures in many of them annoy me. The Chinese abhor polished rocks like we like. They think they look cheap and trashy like plastic. They prefer only natural satiny finish that occurs in nature.
Under a disguise to hide that I wasn't a foreigner, I was recently allowed to see a family Yangtze River agate mining operation east of Wuhan. I saw a vibratory tumbler that was frightening. I estimate it held about a ton and it was mounted on a concrete pillar into the earth. It still shock the ground for 30' in all directions. Employees maintaining this beast had to wear ear protection and I could not talk to my friends even though I was 100' away from it it was so loud. I got up higher and saw what was in it and it like a boiling cauldron from Hell itself. What a tumbler!
Perhaps my post intro will trigger some curiosity about this or that and I look forward to making some new friends.
Thanks to all for the information shared!
Bob in Stillwater, OK