While attending the “Totally Turning” symposium at Albany N.Y. in October 2003, I had the pleasure of watching a demonstration on the turning of Soapstone, needless to say, I found it interesting and decided to give it a try. I’ve turned a few pieces, a couple successfully, learned a few things, took some notes and pictures. Hopefully, this article will be of some use to somebody with less experience than I have, that is interested in turning Soapstone.

The stone blocks I used are 3"x3"x5" and weigh 4.5 Lbs., not something you’ll want to eat for lunch, so wear a face shield when turning! Of course, dust isn’t good for you either, so wear your dust mask too!

Soapstone is the softest of the stones and doesn’t respond favorably to conventional metal centers or chucks, it crumbles. The method I learned is to drill a hole in the top and use a wood dowel glued in and drilled, to mount on a screw chuck..The bottom is fitted to a wood glue block which will become the base. I turned a couple wood centers to use in the live center. Scraping tools seem to work better, a skew or gouge will work, but the trailing heel of the bevel will score the stone.

The stone can have natural separations (cracks),between the layers of the stone which can come apart. They may appear as a white line through the darker stone. The cracks can be sealed with thin CA. You need to check periodically and seal them.

Don’t be too aggressive when hollowing and use sweeping cuts, you don’t want to bury the cutter and have it catch. This happened to me while turning my first piece, although I used an epoxy adhesive, the stone separated from the glue. I was able to re-glue the joint and continue.

Turning stone won’t take the place of wood for me, but I do find it to be an enjoyable alternative. Combine the stone with some wood accents, and there are a lot of possibilities.

The top of the soapstone block has been drilled with a Forstner bit and a dowel has been glued into it. It has now been drilled for mounting to a screw chuck.

The blank is roughed down with a scraper using a wood center in the tailstock for support. I’ve found that scraping tools seem to work better because the heel of the bevel on a skew or gouge, leaves a score line behind the cut. Stop periodically to check for cracks in the stone, seal cracks with thin CA. I used a shop vac and crevice attachment tool taped to the scraper (blue tape) to collect most of the dust.

Turn the bottom as flat as possible for a good glue joint. A tenon will help align the blank to the glue block, which will later become the base.

The glue block, which will become the base, is turned with the mating surface flat and a mortice cut to match the tenon on the stone. At this point, the stone can be glued to the base.

The stone has been glued to the base using epoxy adhesive.

With the wood plug still in the top, you can use a standard cone tail center. While using the tailstock for support, I turned this at around 1200 rpm.

I used a square scraper to true up the blank and a skew to contour the wood base.

I came across these hard spots that are a different, harder mineral. They take a little extra effort and sharpening to flatten them. I haven’t had any break out so they are not really a problem.

I used some 1/4" steel stock ground to shape for shaping small contours.

An old, cheap gouge ground and filed to shape made a nice beading tool to shape the rim.

After shaping with the scraper, I switched to a skew with a slight burr, laid flat to clean up the surface. Very light cuts are necessary. Check for cracks and fill with CA.

I found 400 grit sandpaper to be a good starting point for sanding. Using 400 is actually somewhat aggressive with the soft stone but with a light touch, it will help smooth out rough spots. After sanding with 400, 600, a gray 3m pad, a white pad and a black micro mesh pad were used. This is the final surface of the stone.

This surface is relatively free of scratches and ready for a finish. You can, of course, polish higher if you choose to. I didn’t care for the color of the mahogony base with the stone so I’ve dyed it black.

After removal of the tailstock for support, I turned the speed down to about 800 rpm. I’ve removed the wood plug with a spindle gouge, cleaned up the inside with a scraper and drilled a depth hole. Don’t be too aggressive when hollowing or you can break the soft stone at the glue joint. I have used both the Sorby Multi-Tip hollower and the Kelton Mini hollowing tools for the hollowing.The Sorby worked well, but I found that I had to rotate the cutter too often within the narrow confines of this piece. I tried the Kelton with a straight cutter in one end of the handle and the hooked cutter in the other end, and found it quite efficient. Then I used the Sorby with a shear scraping cutter to clean up the inside.

This picture shows that stone will blow out just like wood if you get caught napping. The vessel in subsequent pictures may look different. ;-)

Turned, hollowed and ready to finish

This is how the stone looks with a finish on it.I have applied one coat of gloss polyurethane and burnished it to a satin finish.My wife likes shiny,so it will be finished to a gloss.:-) The piece I saw turned at the demonstration was finished with a spray lacquer,so finishing options are as wide open for stone as they are for wood. On my first stone turning,I made the mistake of using a friction polish and although it looked good, it didn't hold up very well,small white nicks in the stone became visible. So for this piece I've decided to use varnish for a more durable and protective finish.Plus,the amber tint of the varnish gives a slightly warmer color to the stone.

The completed jar, finished with three coats of varnish.

My first attempt, fitted with an Ebony lid, finished with a friction polish.

The survivors. The piece on the left was finished with the friction polish, leaving the natural texture of the stone. The right piece, with the smooth gloss and warmer color of varnish.

Soapstone Sources (click on any of the links below)
  

1) Stoneman Distributors - London, Canada
2) Sculpture House Stone Turners - Skillman, New Jersey
3) Lee Valley - Canada
4) Sandy Cline - Lakefield, Canada
5) Blackpearl Soapstone - Charlottesville VA

Soapstone Properties (click on any of the links below)

1) Properties of Soapstone including the quarrying
2) Properties of Soapstone