Bead Shaping & Grinding 101 - The Very Basics

  • Jan 23 2015
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We are frequently asked how to get started in the art of rock cutting and Lapidary work. A broken piece of rock or pebble fairly thin will suffice to get you started, along with wet/dry sand paper in multiple grits, or better yet a dremel or other rotary tool.

1 inch in length, ¾ inch wide and ¼ inch thick, the closer the shape is to a dome on one side and flat on the other the easier the work will be can be held by hand and worked as follows:

The simplest technique is to tack some wet/dry sandpaper to a board and rub vigorously. The flat side can be done on the board. Hand hold the sandpaper and you can even create cups or a trough to get better ie. cutting/sanding action for a curve or dome. Your sand paper should be wet, and start with the most aggressive grit paper, working up the numbers until smooth. Agate can be started as low as 80 grit and 600 grit brings you just below polish level. You will get your hands dirty and, if you work hard enough, even get blisters and callouses. Polish at about 1200 with cerium oxide or tin oxide which will work for many rocks. These polish compounds can be applied with a soft cloth or even a buff applied to a mechanical devise. The polish is put into a small dish and then a little water added until a slurry or paste is able to be applied to the cloth. The numbers we use are like the numbers for nails or wire gauge: the higher the number the finer the grit.

If you are like me and a DIYer, you will soon try and mechanize. Local HVAC guys will gladly let you strip out some heater fans. Find a mandril and add a wheel to it. Be safe here: a drop of water at 60 MPH hurts and a spec of stone can maim. When using the old standard ¼ HP motors and a madril with an 8 inch wheel, the surface speed gets to around 60 mph. FYI…diameter x pi x revolutions per minute=measurement per minute. The wet grindstone wheels are porous, sooo if you hang an IV bag and drip some water, be sure to spin dry so the wheel will not explode. Any damage to the wheel makes it unusable. Work the stone across the wheel from side to side and do not gouge the wheel. Eventually you will need to cut the wheel down with a tool to even it. I still use a bucket with a hose glued into the bottom, a small on/off valve can be found at the local hardware along with the hose and everything previously mentioned. Check out some books on lapidary to get much more info.

For the next level electric sanders can be either used by beginners and advanced lapidary artists. I have even worked a belt sander half on and half off to make a unique shape.

Some big box lumber companies sell diamond saws meant to cut tile. These can provide plenty of small stone slabs before you need a new diamond saw blade. Follow the instructions.

Plaster of Paris can be mixed and poured into a box to hold a stone to get a flat surface to either grind or saw. Then when sawing the next cut can be parallel to the first. In the real world people are still using a bow to move a cutting wheel back and forth to drive their wheels, so advance at your own speed.

One of the worst problems for getting started is to get those pesky buzz words figured out, so after you use a dictionary and the word still does not make sense then feel free to email me and see if we can work it out. If we can get enough people interested we should put it out on the community board for all to find.

The same concepts could be use for any glass beads. This may be especially useful to repair beads even vintage trade beads. Carefull here some may say a damaged old bead is better than a repaired old bead. You decide.

For more on the subject I have done a second more advanced article in my blog

Good luck, Marvin

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