PatRocks
off to a rocking start
Member since July 2015
Posts: 20
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Post by PatRocks on Aug 8, 2015 12:01:59 GMT -5
I thought the first 3 stages of tumbling were going just fine, until I did the final polish and many cracks showed up.. I hope I can post this picture.
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Post by Jugglerguy on Aug 8, 2015 19:29:22 GMT -5
My guess is that those cracks were there all along and just became more visible as the rocks became more polished. The white, translucent ones are quartz. I pick up a lot of beach quartz here in Michigan and it almost always has internal fractures. It also looks like you have some granite in there. That's another rock that is difficult to polish because it's made of minerals af varying hardness. The softer stuff starts wearing faster than the harder stuff in the later stages of tumbling. It always looks good until the end when the undercutting begins. I've learned to leave those two types of rocks on the beach, except when I can't help myself. It's a work in progress.
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PatRocks
off to a rocking start
Member since July 2015
Posts: 20
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Post by PatRocks on Aug 8, 2015 20:39:29 GMT -5
Thanks Jugglerguy! I have a lot to learn and appreciate the feedback. The first thing I need to figure out is what rocks are best to tumble. I did find a home for my stones in a glass vase of shame.
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herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
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Post by herchenx on Aug 8, 2015 21:39:38 GMT -5
Lots of granite in that batch, they are tough being mixed hardness material. You did get some shine on some of the rocks, so I'd say perhaps leave the granites for a different day and try to focus on more solid, similar hardness material like quartz, the pink stone left of center, and rocks that have less fissures in them.
It's fun to have a first tumble though, and you will only improve from here!
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ringlord
starting to shine!
Member since May 2015
Posts: 31
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Post by ringlord on Aug 10, 2015 11:10:13 GMT -5
From my experience, if there are any fractures, cracks, or pits in your rocks moving into the polish stage, the polish will work it's way in there and become visible once it dries out.
Run your fingernail over those white lines and you'll probably feel it 'tick' over them, or you may be able to feel a slightly rough area there with the pad of your finger or thumb.
My advice: be obsessive about your rocks coming out of the rough tumble stage. Feel each of them for imperfections like this. Tumble them until they are smooth. If there is a large fracture or rough area that you don't think will tumble out, then take a trim saw to it and cut that portion off. Some rocks will be so imperfect that they might never tumble well.
I had plans to start a thread like this of my own, looking for advice on how to best polish a rock with some fracturing or other imperfection. I have heard that sugar can dissolve polish, but don't know if it's true. I may try it next time by putting sugar into the burnish stage, post-polish.
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Post by gingerkid on Aug 10, 2015 13:54:07 GMT -5
Congrats on your first batch, PatRocks! There's definitely some shine on them, and I wondered if you took your pic of your tumbles in the sunlight? Nice shapes, too. For tips on tumbling materials that undercut, such as granite, please check out jamesp's threads.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,563
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Post by jamesp on Aug 10, 2015 16:21:52 GMT -5
My granites look like that too Pat. Granite a difficult tumble. Go with agates and enjoy. Even with the thickest slurry the material around the cracks lets go and leaves crevices. Impacts from tumbler I suppose.
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PatRocks
off to a rocking start
Member since July 2015
Posts: 20
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Post by PatRocks on Aug 10, 2015 21:46:48 GMT -5
Thanks everyone for the encouragement. I did take my pictures outside, but it wasn't completely sunny out. The first day in two months that we actually had cloud cover which is usually the norm for grey Seattle. Go figure! I am going to give up right now on the granite's which I have plenty of in my rocky back yard. I am going to go and purchase some agates to learn on with my tumbler this weekend. I am going to be very patient right now with the first stage and not hurry the process up. I am excited I bought a flat lap to play around with. That will help with me learning types of rocks and hardness, plus flatting the bottoms of my pet wood I got at a rock swap meet a couple of weeks ago. I cannot wait until it shows up on friday I will read Jamesps's thread. I now spend more time on this site than my other favorites like ancestry.com and facebook. This hobby is very addicting..
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Shelbeeray
has rocks in the head
Member since January 2006
Posts: 688
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Post by Shelbeeray on Aug 17, 2015 19:52:09 GMT -5
Welcome to the hobby. I think the biggest challenge in your first tumble is that you have several different types of stone. Not all play nicely together. Quartz and quartzites tend to be pick. They like to fracture. Granites and granitidorites are picky too. I tend to polish those on a lap because, depending on the composition, I've found I can get a lot of undercutting.
Agates and jaspers are my favourites for starting out. You are getting some nice shapes. Good luck with the rest!
Enjoy the flat lap! Once I started with a lap, I got really picky about tumbles!
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PatRocks
off to a rocking start
Member since July 2015
Posts: 20
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Post by PatRocks on Aug 17, 2015 23:13:05 GMT -5
You are right about using the flat lap Shelbeeray, I am starting to figure out the different hardness of stones. This is going to help with my next tumble.
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