How to inlay turquoise with Hot Stuff and Super T CA glue

Guide and inlaid works below by Uel S. Clanton
photos by Joe Johnson

Satellite City adhesives used in this guide

Hot Stuff CA glue
Super T medium gap-filling CA glue

General Guidelines

Sand the turning for a 220 finish.

Apply a coat of DEFT wood finish to the turning. The DEFT will keep the CA from penetrating the unfinished wood and will make smoothing of the inlay material easier.

Use a “PEAR” or “ROUND-END CROSS CUT” but that is designed to cut both on the face and side to deepen and widen the design or to a depth of about 1/8 inch into the wood.

Fill the design with turquoise. Finer material should be used at the edges. The inlay material will show best if some size range is present.

From one edge, slowly add Hot Stuff thin to the inlay material. Let capillary action “wick” the thin CA glue and then fill with Super T medium. A brief spray of accelerator should be used to set the CA glue.

Grind, file, sand (as appropriate) until the turquoise is flush with the wood surface. NOTE: This step may have to be repeated several times to obtain a smooth surface.

Because of its hardness, turquoise should be sanded with 320, 400, 500 and 600 grit sandpaper. Power buffing will be required to bring out the full beauty of the turquoise.

When the surface is smooth, rub on one thin coat of lacquer (thinned 30%) and after about thirty minutes apply an unthinned coat of lacquer. Let dry at least twenty four hours. Power buff the total turning with DIAMOND WHITE ABRASIVE. Pay particular attention to the turquoise. Additional sanding (400, 500, 600 grit) may be requires to remove the scratches in the turquoise.

Tools

A 20,000 RPM flex shaft grinder (about $200), a 35,000 RPM micro motor ($600 - $900) or a 300,000 RPM pneumatic powered hand piece ($200 - $1,000 plus) can be used to shape the wood for the turquoise inlay.

You can probably obtain used burs from your dentist, (trade a bowl or vase.) Burs that are designed to cut both on the face and side work best. I suggest “pear” or ROUND-END CROSS-CUT burs for best results.

An OPTIVISOR with a 2 or 2.5 magnification lens is the best compromise between magnification and depth-of-field.

A six inch NICHOLSON brand FLAT BASTARD file is the best compromise for removing excess inlay material.

After “smoothing” the turquoise with the FLAT BASTARD file, use one or more 3M FLAT –PAD DIAMOND FILES to remove the file marks. The files are color coded: BLACK is 120 grit, RED is 200 grit and YELLOW is 400 grit. The 3M files come in sets of four with different shapes but all the same grit. The cost is about $18 per set.

Hardness

The hardness of a mineral is measured by the resistance which a smooth surface offers to abrasion. The degree of hardness is determined by observing the comparative ease of difficulty with which one mineral is scratched by another. This is referred to as the Mohs* scale of hardness.

10 Diamond
9 Corundum
8 Topaz
7 Quartz
6.5 File
6 Orthoclase 5.5 Glass
5 Apatite
4 Fluoride
3.5 Copper Coin
3 Calcite
2.5 Fingernail
2 Gypsum
1 Talc

* The scale is linear for minerals 1 – 9; on a truly linear scale diamond would plot 42.

Filing defects and pinholes

There will always be a few spots that didn’t get completely filled with stone, or places where the stone was knocked loose during the leveling process ~ this is normal and unavoidable. Before attempting to patch these defects, protect any bare wood near the repair site with wax to prevent CA glue from discoloring the wood, but keep the wax out of the void.

If the defect is large, clean out the void with compressed air, and place new stone chips into the opening and tack them in place with a drop of CA glue. Repeat this for all the large voids.

Now sprinkle stone dust into any remaining small voids and pinholes, and around the newly set stone chips, and add CA glue to saturate the dust. Once the glue has dried, sand with 80 grit to bring the patches level with the surrounding stone.

Any remaining defects can usually be patched with Super T medium CA glue – just place a drop in the defect and let dry.

Finishing and polishing

Continue with the random orbit sander through the complete grit sequence. I typically sand to 800 grit to produce a nice smooth stone surface, then buff with a little rouge to polish the stone perfectly smooth.

You can use most any finish at this point. I like to use lacquer as a finish, and it is applied to the stone the same as to wood – I spray it on in many thin coats. Then, once it has hardened, I buff the final piece to a satin finish.

Conclusion

I hope that the information above helps to inspire you creatively, and gives you some new ideas that will enhance your woodturnings. Stone inlay is a fun technique, and a great way to make your woodturnings stand out from the crowd.

One additional note: don’t be discouraged if your first attempt at inlay doesn’t meet your expectations – just learn from the experience and continue on to your next piece. I have many pieces lining the walls of my shop that didn’t come up to my standards – the key to learning is doing. If you don’t keep an artists journal, then start one today ~ take notes about what went well, and what didn’t go well, and you will quickly correct the errors and put them behind you.

References “Stone Inlay” by Stephen Hatcher
American Woodturner magazine, Winter 2002