Tumbling with vibratory tumblers

Description

Vibratory tumbling is a great way to tumble stones, small slabs, cabochons, or preforms. Enclosed are a few basic procedures on how to use a vibratory tumbler. The use of a notebook to keep track of the material you tumbled, the grit steps, days for grit completion, will be of help. Since vibratory tumbling gives such quick results, CHECK YOUR STONES DAILY. Use stones of the same hardness in the tumbler. The tumbler bowl should be 50-75% full when loaded. Use a filler* (see note below) to keep your stones from chipping or spalling. Vibratory tumbling does not round the stones as much as a barrel tumbler. (Note: The use of a barrel or rotary tumbler for the rough grit stage will extend the life of the polyurethane liner of the vibratory tumbler). ROUGH GRIND or #80 silicon carbide, abrasive grit stage is for smoothing the stones or edges from slabs. Add grit at 1 tablespoon per pound of stone in the tumbler. Rule of thumb is an equal amount of water and grit. Slurry thickness is IMPORTANT. As the stones wear away, the rock dust, moisture and abrasive mix form a slurry which coats the stones. If the slurry is too thick, grinding action will stop. It may be necessary to add more water, a teaspoon at a time, or sometimes the slurry must be discarded. In that case, clean stones, and add grit and water and continue tumbling. Estimated time for rough grind will be 1-5 days. When this stage is completed, thoroughly clean barrel and lid. Clean stones by rinsing them off on an elevated fiberglass window screen and rinse off with the garden hose and rinse several more times. (Grit in the kitchen sink will clog the pipes.) Grit left in vugs or crystal pockets will contaminate the next stage if not removed. The harder the material, the more steps of grinding or grit should be used to get a smooth surface. Stones having a hardness of 6 or more should use the following grind or grit sequence: 80, 220, (400/optional,) 500, (aluminum oxide 800 pre-polish/optional) then polish. From 220 grit stage on, the average time for tumbling is 24-48 hours. Continue all the grit stages with the same amount of grit and water as before and tumble, wash/rinse off grit, clean barrel and lid, etc. If you have cabochons hand prepared through the 220 grit stage, they may be added to the tumbler at the 400 grit stage. FINAL STAGE IS POLISHING: a recommended polish is Rapid Polish #61,  (use 1/2 level teaspoon for 4 pounds or rock and media in the tumbler,  also  tin oxide or cerium oxide are used in the ratio of one tablespoon of polishing powder for each pound of stones. Add water in the ratio of 1/2-1 tablespoon per pound of stone. Add a filler for this stage which aids in thickening the solution surrounding the stones and cushions the load. (FILLERS: hardwood sawdust, maple pegs, small masonite chips, rice hulls, rubber pieces, or ceramic media.) For most hard stones use about 1/4 cup of filler per pound of stone. Obsidians will need 50 to 75% filler. IMPORTANT: Do not attempt to operate this cycle with mixture too thin. Load must be coated with a thickened “batter” like solution in order to obtain optimum results. Should the mixture require the addition of water, add sparingly and slowly to bring the mixture to a “thick batter” stage. Approximate time for polish stage is 2-3 days up to a week. When stones have reached the desired polish, they will look as good dry as wet, then wash the load. A burnish stage for additional buffing or removing any minute traces of polish, may give the stones additional sparkle. Use a powdered detergent, such as Borax, 2-3 tab. and an equal amount of water and tumble 3-4 hours. Another option if polish is noted on the stones, use a small amount of Ivory soap chips for a 1-2 hour cycle. It has come to our attention, using one more grit sequence of 1000 grit gives even better results. Wash & dry stones with a terry cloth towel and ENJOY!