From time to time we get calls from people wanting help with a hydraulic saw. Generally a hydraulic saw is not worth your time, (Exception: 36″ Contempo). The best plan is to convert to gravity feed and use an all thread screw feed. If people want to convert to all thread, this spring CigarBoxRock will have some components available. You are welcome to contact Tim541-289-5574  for advice and information.

 

Rock Tumbling Mumblings…..

Tumbling rock is more than just dumping rocks into your tumbler, adding grit, water and  starting the tumbler.

Taking a few minutes to look at your rocks before starting can save you time, grit and disappointment.

Not all rocks will “hold up” to tumbling.

Not all rocks will get a high shine.

Some rocks need special help.

I have included some pictures of  finished  rocks  that are less than perfect.

All rocks were tumbled in grit purchased from CigarBoxRock.

Step 1- 60/90 Silicon Carbide

Step 2 – 120/220 Silicon Carbide

Step 3- 1000 Aluminum Oxide

Step 4- 8000 Aluminum Oxide

Steps 1-3 in  a Thumbler, and Lortone rotary tumblers and Step 4 in a vibratory tumbler  (Mini Sonic) or Lotto.

( I have both and I am not sure which was processed in which vibratory tumbler)

All of these have issues. Can you guesss what they are?

 

The first 3 are too soft …. will not shine to a high gloss.         The two  pieces of chalcedony have deep pits — Might benefit from starting over.    The 6 pieces of jasper  have areas that are softer than other parts may be a differnet mineral make up, or  have areas that are “punky”.  These will not get a consistent polish.

 

Fractures and Cracks. Polish Residue                       Tiny pits! More time in Step 1 needed.

You need to understand “hardness” as it applies to tumbling. Softer stones can erode quicker.  This is why when tumbling all the rocks need to be of similar hardness. Take the time to check your rocks and then sort according to hardness. While sorting, also look for obvious fractures, cracks and pits (aka ‘vugs”). These can harbor grit from an earlier stage that if it dislodges can scratch your stones.  When you get to the polish stage, polish can get stuck in cracks and pits and then you have stones with ugly white residue.

Some shallow pits will smooth out in stage 1, but cracks usually will not. I will take a stone with crack or fracture running through it and take it to my trim saw. By starting to cut down the crack the stone will usually split on that crack. You will have smaller tumbles, but the quality of those tumbles will be much better than a single one with deep cracks.

I run rock only in Step 1 and use ceramic media in Step 2-4. My barrels are loaded with a mix of sizes of stones.

My process is to start in Step 1. I have a designated tumbler for Step 1. I check it weekly and examine my stones. I sort at that time. Some may move on to Step 2, some need more time in Step One

and some  get tossed into a bucket as not worth it. (These I may re visit later, may be they can be salvaged). Step 2 I run in a 12 pound Lortone if I have a lot, or one of my 6  pound barrels on my QT 66. Step 3 is  done in a 6 pound barrel. Step 4 in a vibratory tumbler.

I rinse in Borax prior to Steps 2, 3, 4, as well as a post 4 rinse.  I also run my completed Step 4 through an Ultra Sonic Cleaner.

I will show some of my best tumbles in a later blog.