Mineral Inlay

Calcite is first crushed and sorted into five different sizes using kitchen strainers.

After turning three years I felt I needed to add another facet to my hobby. I wanted to add interesting character to pieces where the wood offered little or no figure or character of it’s own. In July 2011, I attended a class  at Arrowmont Folk Art School in Gatlinburg TN, given by Stephen Hatcher. That week long workshop started me on the fascinating process called mineral inlay.

First you must carve out your design, or the rim around a bowl. In this example the tear drop shape on the fork and spoon set. I am using a Dremel tool with a high speed boring burr. You must be very precise as you want your edges straight and crisp. Patience and a steady hand are essential.  As the burr is carving out the shape you must stay just inside your pencil lines. It is best to carve straight down into the wood about 5/16 inch. Try to keep the bottom somewhat flat. It is important to go deep enough but not too deep.

The next step is critical. Omitting it could ruin your piece! 

Super thin CA glue is used to bond the mineral to the wood. However, using very thin CA glue will stain the wood and never come out. You must protect the wood surface from soaking up this thin CA glue. I use a solution of 90% Denatured Alcohol and 10% one pound cut of dewaxed shellac. Mix this and put it in an industrial type spray bottle. Spray a little on your hand. When it drys in a few seconds, your hand should be slightly sticky. Spray this mixture on the surface of the wood and let it dry a few minutes. Do it again. You must do this step every time after you sand the inlay. Don’t forget!

 Next lay in the largest crystals. Use the biggest ones that will fit into the groove, making sure they are “proud” of the top of the wood. Space them out. Use your sense of color and shape to arrange them into the entire carved out groove.

Fill in around your large crystals with the next smaller size. Pack them in as tightly as you can get them. After your groove won’t accept any more of this size crystal, go to the next smaller size crystal. Sprinkle them in around the larger crystals. You will notice that they fall down to the bottom of your groove and fill in around the larger crystals. Continue until they have filled in completely around the larger crystals.

Using the sugar sized crushed crystal fill in all of the holes, voids, cracks and spaces. I sprinkle it on very lightly so that it will fall in around the larger crystals. The idea is to get as much of the groove filled with crystal as possible. I use a large magnifying glass mounted on a scissor arm with a light around it to inspect the placement of the crystal.

You might want to vibrate the wood to help the crystal settle into empty pockets. Be careful if you do this as you can easily vibrate everything out of the groove and all over your work bench! You should have a mound of crystal piled up “Proud” of the wood surface. 

Once you have the minerals loaded into the groove, fill the groove with very thin CA glue. Use the thin CA glue liberally. I mean fill that groove so that the glue is almost running out and over the sides. Drip it in and let it soak in. Continue until the crystal is drenched. Let the CA glue dry for about 24 hours.  It will look like one piece of molten glass and be very hard and dry.

The next step is power sanding. I start with Klingspor Stearate A/O 80 grit PSA sandpaper discs used on my variable speed drill. You can get them from Klingspor’s Woodworking Shop.

As you can see from the photo, the Calcite crystals are all glued together into one solid mass that sets “Proud” of the wood surface. The Calcite must be sanded down flush with the wood. Be careful not to build up too much heat on your sandpaper or the inlay.

After you have power sanded the Calcite down to the wood, inspect the surface of the inlay using a magnifying glass. You will notice that there are a few tiny holes and crevices. You must fill those in with crystal and add more CA glue. But not before you spray the wood surface with the Shellac solution again.  

Power sand this time using 100 grit paper. Inspect the surface again and repeat the process until the inlay surface is smooth. If the surface is solid, from this point on you will not be using CA glue, so you do not have to spray shellac after sanding. Power sand the inlay starting with 120 grit and go all the way through 5000 grit. Your Calcite will be polished and gleaming.