Monday, May 12, 2014

Rock and/or roll!

So way back when in the post "Rocks (and not the ones in my head this time)" we started a batch of rocks in the tumbler and brought it through the course step and into the medium; now a little over a month later the batch of rocks has run through the other steps and are ready for there closeup,

As a reminder, when you are changing a tumbler DO NOT PUT ANYTHING DOWN THE SINK! This grey liquid (yes we got the color we were expecting this time)...

turns into cement faster than you would believe (there is a bucket of it out back of the house that has overwintered better than some of the local sidewalks!)

One serious suggestion I have for while you are changing barrels...

Screw all the parts of the lid together. This keeps parts of separate lids from getting mixed up or just plain disappearing. One time I had an inner lid end up under the rocks in the barrel!

 Here are our rocks after the medium, and here

they are on the official cafeteria tray of bench cleanliness. When they look like this dry then we're there, but we're not there yet! At this point we're again checking for broken stones and other 'show stoppers'. We got the worst out after the rough but we check every time. No major issues so it's every body in the pool in the fine barrel.

There is a little more space this time and we would really like to start cushioning the stones so they don't break. fortunately we have a secret weapon...

Sorry gang not all secret weapons have killing capacity. You can buy plastic pellets from your tumbling supply supplier, but you can get the same ones from JoAnn's or somewhere similar in a larger pack and for less. Like our tumbler barrels you can reuse the pellets but make sure you use them in the same grade every time (do not move your medium pellets to fine or the fine ones to polish!). The pellets tend to pick up the grit and will ruin a later step.

So here is the barrel loaded out with pellets that are ear marked for fine (note: no teddy bears were harmed in the making of these shiny rocks!). You can see that the pellets are carrying some of the fine grit already. Remember that the pellets will float so sight on the top of the stone for your water (bring it almost to the top of the stone). Next four tablespoons of fine grit. In the last few runs I have been trying an aluminum oxide pre-polish; I am really not satisfied with it and will be going back to 600 grit silicon carbide. Disassemble, put on and tighten your top, then back on the roller for another 7-10 days.

 After the fine has run for another 10 days we open and empty. I'll save you the picture of the barrel this time but we have added one piece to the straining rig...

No friends and neighbors I have not lost my senses and I'm not trying to be funny. the little blue basket has holes large enough to let the plastic pellets fall through but small enough to keep any rocks worth keeping in place. It makes separating the pellets much easier. The remaining pellets can be floated out when you rinse the stones in a butter tub or bowl.

We proceed with the same basic instructions for the polish step but using aluminum oxide or cerium oxide (better, more expensive and a tan color instead of white (unless you buy 'french cerium' which is white and meant more for faceted stones, lasers and spy cameras. Don't waste it on tumbling!))

This is a bag of aluminum oxide polish, a cheap, fairly good last step for tumble polishing. Despite it's color and consistency please do not confuse it with powdered sugar, talcum powder, coffee creamer, cocaine, laundry powder or anything else besides a rock polish. It would be bad. 

For this step some sources recommend using 1 1/2 or two tablespoons instead of three or four that we used in previous steps. This is a personal preference/experience and expense thing. I think two tablespoons works well with properly run stones and silicon carbide in the fine. You might want more with the AO pre polish (or better yet trust me and use the silicon...). But, if you are going to do two tablespoons, it is best (I think) to add some laundry detergent, the jury is still way out on using liquid versus powder.  Some say the liquid works and others say it ruins barrels and polish jobs. I have gotten some really good ones (best batch ever) with liquid and not seen barrel problems. But I have also seen some bad stones come out with the liquid... If some chemistry person would like to explain why the effects of the powder would be different I'll listen, then test; but remember not all stone is the same either!

Run another ten days, pray hard and drain as usual (if you have pellets in (and for polish you probably want to) try that two part rig or float them off).

If you want to you can run the stones in a clean barrel with just stones water and detergent for up to four days. I don't usually do this and I've seen people argue over whether it is necessary, and how long. And oh look that powdered versus liquid detergent brawl is going again... this step depends on your stones, your set up, abrasives/chemicals and personal style. As usual experiment and decide for your self.

Now let's see a few of the stones that came out.. as usual using our very best lined paper backdrop...

I handed both of these over to Lisa before she could claim them. the one on the left actually hit the floor and had the end that would be at the bottom drop off. This was sad as I intended to make a piece of jewelry with this one for Lisa's birthday, but it would have been worse to finish the piece then have it break. As is I just have to modify the design a little and polish the end with other polishing technology.

 Petrified wood. Also handed directly to Lisa for her collection.

Green former pieces of slabs. I'm keeping them. You might see them in future projects.

The lace agate on the left is a future tie clip (part of my next epoxy run...). It's hard to see here but the clear one at the bottom actually refracts the papers lines at an angle.

The top right is the prize here. Like tigers eye but silver/grey. Lisa got this one but I have another coming.

Ok... but...what do you do with them?

I answered the question for the raw stones for the finished ones... that's another story. As the dwarves would say it involves dragon fire and twisted wire...

Here's some twisted wire. The dragon fire comes in an upcoming post!

Assuming I survive a job interview tomorrow, I'm hoping to do more shop stuff for next week.

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