Whatever stage of rock or gem cutting you start with, stone polishing is the final stage that can make or break all your work. Never fear! With these eight tips from jewelry-making and lapidary experts Tom and Kay Benham, you’re halfway to successful stone polishing!
Stone Polishing with Confidence: 8 Tips
By Tom & Kay Benham, Contributing Editors, Lapidary Journal Jewelry Artist, from the February 2010 issue
1. Grind wet. Always grind wet to protect your lungs from breathing in the dust from stone polishing. The dust from some stones, such as malachite, is quite toxic. In addition, wet grinding eliminates damage to expensive diamond wheels.
2. Judge dry. Although we always grind wet, we recommend that you always dry the stone completely before judging its surface. Water on the stone surface will only hide scratches and give a false reading.
3. Use the whole wheel. Use the entire width of the grinding wheel, not just the center. This will ensure a longer life and better performance.
4. Skip no grit. Work sequentially from the coarsest to the finest grit. Don’t be tempted to take a short cut by skipping a grit. The progression through finer and finer grits is necessary to remove the scratches left by the previous grit. The goal is to have the scratches become finer with each grit size until they can no longer be seen. Our experience has been that if you skip a grit, the final polish will show big scratches. You will wonder where those scratches just came from! The truth is that they were there all the time, but you just didn’t sand them out when you were supposed to. If you skip a grit and find deep scratches, you’ll have to go back three or four grits to remove them. It’s always faster to do it right the first time.
5. Polish slow. Polishing is the final step. There are a myriad of polish and stone polishing pad combinations; our preference is charging a soft leather pad with a thin paste of Holy Cow stone polishing compound and water. The actual polishing occurs as the pad starts to dry and the stone starts to pull against the surface. We keep the speed of the pad low to eliminate any heat buildup.
6. Keep it clean. Remember, “cleanliness is next to Godliness” when it comes to lapidary work. To prevent cross-contamination from coarse grits, we are careful to rinse the stone and our hands at every grit change during stone polishing–and we thoroughly clean our machines after each grinding session. Polishing compounds and wheels should be kept in sealed plastic containers when not in use.
7. Believe what you see. Your eyes are your most important tools when it comes to stone polishing. They are your feedback loop. If your eyes tell you that something is not quite right about the surface, believe them. Stop! Figure out what the problem is before continuing.
8. Grind a little and look a lot. This is the mantra of the successful lapidary. —Tom & Kay
These expert stone polishing tips will help you create better gems and cabs for your metal jewelry-making designs–but there’s a lot to learn before these tips can be applied. Learn stone polishing, from basics of stone cutting all the way through getting the perfect polish, with our Gem Polishing Kit. It includes a diamond polish sample kit, in addition to Michael Boyd’s Basic Cabochon Cutting DVD and Freeform Cabochon Cutting video download, three bonus projects, and the current issue of Lapidary Journal Jewelry Artist magazine. If you’re ready to learn a rewarding new technique and be able to create your own custom cabochons, this expert kit is the perfect place to start!