quartzilla
Cave Dweller
Member since April 2020
Posts: 1,227
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Post by quartzilla on May 7, 2020 8:02:26 GMT -5
I can’t stop cracking up on the name of your thread Brace For Big Brazilian. Strong Dr Seuss vibe going on! Good luck on that boulder looking forwards to the progress reports!
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,690
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Post by Fossilman on May 7, 2020 10:14:08 GMT -5
Hell, it's always worth a try to do the uncommon things... I applaud you!! Lookin' good so far!
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Post by knave on May 7, 2020 10:51:06 GMT -5
I can’t stop cracking up on the name of your thread Brace For Big Brazilian. Strong Dr Seuss vibe going on! Good luck on that boulder looking forwards to the progress reports! Haha or that other one, “A couple Brazilians”
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Benathema
has rocks in the head
![*](//storage.proboards.com/forum/images/stars/star_pink.png) ![*](//storage.proboards.com/forum/images/stars/star_pink.png)
God chased me down and made sure I knew He was real June 20, 2022. I've been on a Divine Mission.
Member since November 2019
Posts: 703
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Post by Benathema on May 9, 2020 23:35:04 GMT -5
![](https://live.staticflickr.com/65535/49876807901_10552cb929_b.jpg) Week 3: 36 SiC. 3989g (8.79 lbs). Running total mass loss: 2.4% ![](https://live.staticflickr.com/65535/49876807626_aa8bb18ac9_b.jpg) Onward with more coarse grinding!
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Post by pauls on May 11, 2020 17:57:15 GMT -5
I can’t stop cracking up on the name of your thread Brace For Big Brazilian. Strong Dr Seuss vibe going on! Good luck on that boulder looking forwards to the progress reports! Every time I come across the thread I always giggle and think of a big woman wearing very tight skimpy clothes doing the shimmy at the Carnival. Sorry just my dirty mind.
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Benathema
has rocks in the head
![*](//storage.proboards.com/forum/images/stars/star_pink.png) ![*](//storage.proboards.com/forum/images/stars/star_pink.png)
God chased me down and made sure I knew He was real June 20, 2022. I've been on a Divine Mission.
Member since November 2019
Posts: 703
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Post by Benathema on May 16, 2020 1:06:00 GMT -5
![](https://live.staticflickr.com/65535/49899703048_8d0363d1a2_b.jpg) Week 4: 36 SiC. 3974g (8.76 lbs). Running total mass loss: 2.7% ![](https://live.staticflickr.com/65535/49900221866_91da811292_b.jpg) MOAR GRINDING!
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Benathema
has rocks in the head
![*](//storage.proboards.com/forum/images/stars/star_pink.png) ![*](//storage.proboards.com/forum/images/stars/star_pink.png)
God chased me down and made sure I knew He was real June 20, 2022. I've been on a Divine Mission.
Member since November 2019
Posts: 703
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Post by Benathema on May 30, 2020 3:55:27 GMT -5
Week 5: 36 SiC. 3951g (8.71 lbs). Running total mass loss: 3.3% This should have been last week's update, but things were weird. No pictures, unfortunately... It looks the same as it did before. This stone is currently on hold for reevaluation because I envision it'd take an additional 15+ weeks of coarse at this rate. This thing is hard and that's a lot of time to spend on something to only have one area where banding is visible. Maybe I can find someone with a saw to peel this like a potato to expose some more banding. However, can something like this be done? Absolutely. So far in 5 weeks it's had 135 grams ground off it, for an average of 27 grams per week. As its volume reduces it should grind more efficiently, but truth be told, as is, it could stand to run in a larger barrel. Like what HankRocks found, the ends don't grind effectively since it cant tumble along its long axis. (For Science!)FYI: Less is more on the fill level of the smaller carrier stones if anyone is looking to try similar. I did start adding 1/2"+ stones after the first week. It's a super tight fit. I'm not giving up on it, just need something with a shorter turnaround time during Q, and there's a shelf of cool stuff. Stay tuned for another thread.
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Post by HankRocks on May 30, 2020 5:30:17 GMT -5
Week 5: 36 SiC. 3951g (8.71 lbs). Running total mass loss: 3.3% This should have been last week's update, but things were weird. No pictures, unfortunately... It looks the same as it did before. This stone is currently on hold for reevaluation because I envision it'd take an additional 15+ weeks of coarse at this rate. This thing is hard and that's a lot of time to spend on something to only have one area where banding is visible. Maybe I can find someone with a saw to peel this like a potato to expose some more banding. However, can something like this be done? Absolutely. So far in 5 weeks it's had 135 grams ground off it, for an average of 27 grams per week. As its volume reduces it should grind more efficiently, but truth be told, as is, it could stand to run in a larger barrel. Like what HankRocks found, the ends don't grind effectively since it cant tumble along its long axis. (For Science!)FYI: Less is more on the fill level of the smaller carrier stones if anyone is looking to try similar. I did start adding 1/2"+ stones after the first week. It's a super tight fit. I'm not giving up on it, just need something with a shorter turnaround time during Q, and there's a shelf of cool stuff. Stay tuned for another thread. One thing you will find with the Brazilian Agate nodules, most of the pattern is in concentric rings. The only exception is the Water-Line formation that cuts across the nodule. Unless you have a cut or a break in the nodule, you will never expose the concentric rings, you will be exposing one layer at a time tumbling it. That's not completely true because you probably will expose a bit of the rings as the wear will not be parallel to the concentric rings so some of them will show up as a band, just spaced out a bit. The other thing, Brazilian Agate is very hard. Great for a super polish, a bit more of a task when trying to shape in the tumbler. It's like Montana Agate, great polish, slow grind. The hardness coupled with the size of the piece vs the Barrel size is going to make for a long tumble, as you are seeing. It's one reason I am going to size limit my big tumbles in the future, maybe 2 to 3 pounds at the most. There are are a couple of rock to barrel width and height ratios that are best not exceeded for faster shaping. It's most likely in the neighborhood of 1/2 or less for both. (I think I gave myself a headache attempting to get too technical this early in the morning, must have thought I was jamesp!!) Good luck and keep it coming, its all fun!!
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,281
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Post by jamesp on May 30, 2020 8:38:46 GMT -5
Rocks with a homogenous pattern throughout like wood, moss, plume etc sure make good big rock tumbles HankRocks. Woods and corals make really good big tumble candidates since they have a distinct grain allowing cross cut and parallel to-grain views. And all angles in-between. The inside diameter of the barrel's proportion is critical relative to the size of both the big rock and smalls. For a 6"ID barrel I found 1" to 1.5" agate smalls and a 1.5 to 2.5 pound big rock did best. Maximum big rock dimension/shape as listed: 3.75" egg 3.75"x3"x2" flat oval 3.5" sphere 2"x2"x3" rectangle 5"x2.5"x 1.25" rectangle Never did an 8" ID barrel. But would increase above sizes proportionately until big rock was 4 to 6 pounds. Same 1" to 1.5" smalls. The agate smalls already tumbled to remove sharp edges. Hard coral smalls after being used to tumble three pre-shaped big rocks about 10 days each big rock: ![](https://live.staticflickr.com/65535/49922818321_0e6aef60b5.jpg) A bit softer silicified rhyolite after 3 big rocks as above: ![](https://live.staticflickr.com/65535/49922299008_5145873977.jpg) Not bad considering these smalls only saw 30 days in coarse grit.
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Post by glennz01 on May 30, 2020 17:12:50 GMT -5
I tumble big stuff like that all the time and some larger as I have a larger barrel now. As you seen they take a long time to tumble but helps break up the smalls fast. It will polish nice but I run my polish thick like a past rather then the standard polish amount.
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