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Post by tims on Jun 10, 2016 18:37:39 GMT -5
Lots of good info there, thanks Shotgunner. Just what I was needing to know.
Jamesp thanks a million for the link, I've looked and looked for someplace in the US to find similar pads. I'm going to order a 50 and 100 to start and see how grit works from there, but may well end up getting the full set down the line.
Awesome. Thanks guys.
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Post by tims on Jun 9, 2016 20:07:02 GMT -5
I didn't want to hijack another thread with a myriad of questions, so here goes.
I put about 90 minutes into a slab with minor saw marks and can't see a lot of progress yet. It is slightly less dull than the unpolished side of the cut. I'm using 80 grit on glass with a 2.5"x4" slab of Teepee-ish agate.
Questions:
Is 80 grit too fine to start with? I've only got 80, 220 and 400 on hand.
How wet should the grit be? When I first wet the grit the rock glides easily, but i'm not sure if that's a good or bad thing. As the slurry dries it gets noticeably more difficult to move the rock around but in my mind I associate more resistance with better polishing action.
How durable is the grit? Should I be swapping out to fresh grit every few hours, or is it ok to keep using it even for multiple rocks? Any guestimate?
Can I let the grit dry and then add water later and use it again?
Does the grit need to be washed off after polishing, or is it just polishing compound that turns into cement if you let it dry on?
And lastly, why is my left hand so stupid? ![:)](//storage.proboards.com/forum/images/smiley/smiley.png)
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Post by tims on Jun 8, 2016 19:18:00 GMT -5
Thanks for sharing. How much work was it to get to a decent polish time-wise? Any details you'd like to share about the process would be welcome.
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Post by tims on Jun 6, 2016 19:53:35 GMT -5
Mad scientist indeed, thanks James. That thing just eats rock. The bench rig is cool and looks to give a very fine polish.
Is there a trick to setting the rock to the polishing wheels in order to keep it flat and not catch an edge on the segmented pads? Or is it even an issue when they're spinning?
And where do you get the diamond segments? I found some 6"x2" plated diamond blocks for about $10 each and was thinking of getting 3 and just laying them flat as a hand polishing surface, but it's possible that hand polishing is more fun in theory than in practice.
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Post by tims on Jun 6, 2016 12:11:56 GMT -5
Peculiar stuff there. I find little balls and tubes of gray chalcedony that almost looks like moss agate but no inclusions, sometimes embedded in limestone and sometimes separate where the softer matrix is gone. That looks like an opposite type of formation where the round cavities were the soft material, or maybe even gas or liquid pockets? Neato anyway.
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Post by tims on Jun 6, 2016 11:56:50 GMT -5
I like the tire as a basin. The rest is simple.... How fast should a 24" lap spin? I will be at class tuesday night. Ill check! Way down in the comments he said it was running 80-100 rpm.
I think the material is ocean jasper. I saw that hand polish too and am going to try it when my glass gets here, I've got a few bags of 50 year old grit and am going to splurge on some polish. Be sure to use tempered glass if you like your fingers.
captbob I think those are some kind of industrial diamond polishing blocks. I've been trying to source something similar on the cheap for the rough stage and will post if I have any luck.
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Post by tims on Jun 5, 2016 12:18:21 GMT -5
That takes a lot of grit! What is the grit series? What polish? I can't see the jars on my small cell phone. From the description:
120-220-400-1000 of silicon carbide grit Polishing ceroxid powder.
For that setup I think i'd even tolerate the cat.
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Post by tims on Jun 5, 2016 0:14:12 GMT -5
Unless you like cats, flowers and goldfish the fun starts about 47 seconds in.
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Post by tims on Jun 4, 2016 23:53:46 GMT -5
I was trying to incorporate rocks and stars into something but kept coming up with potential trademark violations. Best of luck with the shop, it sounds like a fun occupation.
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Post by tims on Jun 4, 2016 21:16:31 GMT -5
Several in there that look agate-y. Nice variety. Do you plan to tumble them?
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Post by tims on Jun 4, 2016 21:06:52 GMT -5
OK cool, I should have just stuck with plain rocks until the blade broke in better. I didn't consider using a solvent but i'm sure that would work fine, especially to get into the cavities.
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Post by tims on Jun 4, 2016 20:59:11 GMT -5
That botryoidal stuff is cool. Do people polish pieces like that or just keep them natural?
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Post by tims on Jun 4, 2016 14:13:54 GMT -5
I'm going to have to get a tumbler at some point. I found my grandpa's old sears 2-barrel and it works but it's noisy and the barrels are brittle with age. Will probably pick up a new double tumbler at some point. There are some cool looking combination belt / disc sanders for ~$100 built for woodwork but you probably couldn't waterproof one well enough to run it wet and I assume good belts and discs would notch up the price a bit anyway. I've got a few bags of old grit and am tempted to use a sheet of glass to just get a bit of hand polish going on these slabs so they look pretty on the shelf until I can put some equipment together. As always, thanks for the suggestions, and I'll post the results if / when I make any progress ![:)](//storage.proboards.com/forum/images/smiley/smiley.png)
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Post by tims on Jun 4, 2016 1:37:08 GMT -5
Yeah, polished ... i don't really know how to get there yet. What's a cheap, portable hack for a flat lap? Or is that even what i should try? Each step the water seems to get a little deeper. And thanks orrum. Probably wouldn't have happened without your powers of persuasion.
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Post by tims on Jun 3, 2016 19:53:02 GMT -5
Here's the bottom-left one split with my saw project and the one on the right cleaned up a bit with the dremel:
![](http://westoncountybuyselltrade.com/miscpics/teepeerough2.jpg)
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Post by tims on Jun 3, 2016 19:32:48 GMT -5
Got a few cuts in this evening. The first 3 were pretty much disasters, the 4th ok although plain and ugly. Left to right a blue-gray chalcedony, red and translucent gray chalcedony, tan sandstone chert nodule, gray chert or jasper. Sorry the pic is so washed out but they were all junk so you aren't missing anything:
![](http://westoncountybuyselltrade.com/miscpics/firstcuts1.jpg)
I think part of the problem is the stupid thick yellow paint on the blade. As I cut past the edge of the blade the chunky yellow paint would wear off the blade and bind up in the cut, causing the blade to jam or clumping enough to twist the rock and shatter it. Stupid paint.
Anyway I was really discouraged and starting to think the project was a total failure, but decided to try a big ugly teepee nodule before giving up. All the previous pieces were pretty small, like 1.5" max diameter, and the teepee was about 2 1/2 x 4 1/2" but I just had to try a thick nodule before giving it up. This one actually cut ok and I'm half convinced that knocking half the paint off the blade first helped. As you can see it still managed to paint things yellow:
![](http://westoncountybuyselltrade.com/miscpics/firstteepee1.jpg)
I tried a plastic scrubber then sandpaper to try to clean up the paint but to no avail. Broke out the dremel and got them pretty clean, although there are a couple little vugs that I couldn't get into to clean up. Stupid paint. Anyway, this last cut was enough to breathe some hope back into the project.
My question now: what's a good way to take the paint off a blade so it doesn't gum up the works and paint the cuts? Or does anyone know of a good 10" blade that isn't painted?
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Post by tims on Jun 3, 2016 2:10:44 GMT -5
Image loaded quick. The individual pieces are beautiful and i think the variety of shapes / colors / patterns in a collage makes them even more so.
I'm drawn to the butterfly wing top-right. Haven't heard of pinolith before.
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Post by tims on Jun 3, 2016 1:45:15 GMT -5
It's just like the presidential election, my decision seems totally unqualified but i voted anyway.
Oh wait, unlike the popular vote this one actually has some significance.
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Post by tims on Jun 3, 2016 1:33:36 GMT -5
I've got an old dremel with adjustable speed which should work to clean the crust and matrix away from the agate face. Need to find a good diamond wheel for it still. Thanks for the reminder to keep it wet, i probably would have overlooked that unless it was marked on the packaging or something.
And what is a pendant? Is that just another name for flexible shaft?
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Post by tims on Jun 2, 2016 21:51:06 GMT -5
Here's the saw wet with the new splash guard. It sprays a bit spinning up and stopping but otherwise seems ok --- my water level dropped about 1/4" in 3 minutes in my small 6x11" tray (~32oz. full). Filled to capacity I'm still running the blade a little deep in the water so I might play with the tray some more. After the test I stuck the guard on with liquid nails so it will be the one part that won't be easy to disassemble.
Cost: The bottom of one of my rock buckets ![:(](//storage.proboards.com/forum/images/smiley/sad.png)
![](http://westoncountybuyselltrade.com/miscpics/splashguard2.jpg)
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