richardh
spending too much on rocks
Member since June 2016
Posts: 391
|
Post by richardh on Sept 11, 2016 11:37:33 GMT -5
I finally had some time to check my tumbler and get another look at my Mexican Crazy Lace and Green Tree Agate that have been undercutting. This time I took a couple of photos of what is going on with them in hopes that some of you here might be able to offer some advice on how to proceed. All of these rocks have been in the tumbler (HF 3lb) for three weeks. For the first week they got 46-70 grit SiC and the second two weeks they got 30 grit SiC. The only rocks in the tumbler barrel were Mexican Crazy Lace (started with about 1.5lb) and the pieces of Green Tree Agate you see here. The rest of the space was filled with large ceramic (non-abrasive) media. Any thoughts?
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,182
|
Post by jamesp on Sept 11, 2016 12:46:35 GMT -5
As far as the crazy lace. There is a difference in undercutting and voids and vugs in the rock. Crazy lace has both voids and vugs. Your crazy lace looks like fine material. Your red arrows are pointing at the same stuff most crazy lace has. Don't worry about it. Do not have any experience with the green tree. Pretty sure those areas were going to under cut no matter what you did. I would avoid that rock for any tumbling operation.
|
|
richardh
spending too much on rocks
Member since June 2016
Posts: 391
|
Post by richardh on Sept 11, 2016 13:49:07 GMT -5
Thanks for the feedback, I feel a lot better now. The thing that was making me really worry was that when I cut the crazy lace with the tile saw the surfaces were smooth and now they are becoming pitted. I guess some of the softer material is just going to do that no matter what.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,182
|
Post by jamesp on Sept 11, 2016 14:47:23 GMT -5
Thanks for the feedback, I feel a lot better now. The thing that was making me really worry was that when I cut the crazy lace with the tile saw the surfaces were smooth and now they are becoming pitted. I guess some of the softer material is just going to do that no matter what. Crazy lace has voids and vugs that were probably plugged with sawing mud. Tumbling brings out defects, makes them visible. They are throughout the rock naturally. You can tumble till the rock is tiny and you will still have those voids in it. That crazy lace has some fine colors. They will be awesome.
|
|
|
Post by Jugglerguy on Sept 11, 2016 15:02:35 GMT -5
My crazy lace from The Rock Shed had voids like that too. I did manage to get some good pieces without voids, but some were never going to disappear. If they did disappear, there would just be another to be uncovered. That crazy lace was my favorite tumble ever. Just be sure to really clean it well between grits. I'd tumble it with just water or water and borax a couple times when changing grit sizes. If you're using a vibe, an hour per wash cycle should be fine. In a rotary, longer, overnight maybe?
I had a couple pieces of green tree agate in a tumble mix I bought from The Rock Shed a long time ago. It looked different than yours. It also had voids or soft spots. I'm pretty sure I tumbled it until it was gone.
|
|
ChicagoDave
has rocks in the head
Member since June 2016
Posts: 720
|
Post by ChicagoDave on Sept 12, 2016 7:44:03 GMT -5
I bought a bunch of green tree agate also and have not had good luck tumbling it. It just looks different from everything else I've tried. I might use the word soft to explain. At this point I've been pulling it out and getting rid of it.
|
|
richardh
spending too much on rocks
Member since June 2016
Posts: 391
|
Post by richardh on Sept 12, 2016 21:31:09 GMT -5
I agree the tree agate has loads of soft spots and now my couple of stones are out in the flower bed. I had high hopes for it so it was a little difficult to accept despite the handwriting being on the wall.
On a positive note I think my photos may be getting better.
|
|
|
Post by Toad on Sept 13, 2016 4:48:06 GMT -5
Keep at it. Your photos are great.
|
|