Rocks in My Head

[John S]

By way of introduction I am an experienced (based on longevity and persistence, not talent) wood carver who is extremely interested in stone carving with power and hand tools.  I am particularly interested in working with obsidian and agates, but aside from general "How To" books I've not found a good source of reference material for working with these types of stone.  (I really don't need any more material that covers basic safety and shop protocol.) I've worked with moderate success with soapstone and pipestone, and feel ready to work with the harder materials.

i am using a RAM microtool, a Foredom rotary tool, and of course a Dremel 4000.  I also have a good selection of rifflers, files, and sanding tools.  My chief problem is finding other carvers with more experience and similar interests, so I am excited about finding this forum.

For my first project I am attempting to carve a small (2 inch diameter) ammonite.  I am "prototyping" in wood to get a sense of the design and proportion issues, but the differences in carving wood and stone are somewhat daunting.  I tend to be drawn toward realism as opposed to abstraction  in my  carving. I also suspect that my diamond burr selection is too "low end" and therefore need ultimately to upgrade to better burrs.

I hope to reach a point where displaying my efforts is more than an embarassment.  I look forward to contributing as well as learning from the many skilled artisans who frequent the site.

[Debbie K]

John:

I used to be a pretty active member of this forum, but haven't been on for years. I carve gemstones and have for many years. This is what I do: http://dlskdesigns.com/

Always use a tool with a flexible shaft and water. You always carve stone with water or oil to keep down the dust, as it causes silicosis. I have found that I end up doing much of the work by hand. I use diamond files and then razor blades with diamond powder (bort) of various grades with oil to smooth out the diamond bur marks, along with popsicle sticks, toothpicks, etc. I also make brass burs to use with the bort and oil. Tungsten carbide gravers will also mark most stones of 7 hardness or less.

The bort is available on Amazon and Jade Carver. I have not been happy with sintered burs, they shatter the more crystalline material ; I like the cheap plated ones and the diamond dental burs.

Do not start with agate, as it will be very discouraging. It's the hardest to carve of all the quartz and it'll wear out your tools. Obsidian is a far better stone to begin with. I'd also recommend going a little smaller. Larger stones take a long time to carve and three times as long to polish.

I use a marks-a-lot or pencil to draw on light stones, and a white grease pencil (china marker, available at hobby stores in the art section) to draw designs. The grease pencil is messy but better than nothing.

I got a notification of your post; hopefully I'll get one of your reply. Good luck with your first hard rock carving.

P.S. I will NEVER carve soapstone again. It raises too much dust and I inhaled some of it and couldn't breathe right for months. Most of it (and some serpentine and tiger eye quartz) has asbestos in it. Malachite can make you very ill, it has some type of copper (I forget what form) in it that's killed a lot of carvers in Africa. Stay away from Cinnabar (mercury) and Cerrusite (lead).

Debbie K

[John S]

Debbie, thanks for your thoughtful post.  I appreciated your helpful comments - especially regarding the bort, which I know little about.  I will certainly add this to my workshop.

I can relate to your comments on soapstone. I always use a respirator and face protection when I carve.  I have a downdraft table with dual fans and filters behind it.  I have enclosed the table (actually an old desk which I modified) with a plexiglass shroud on four sides. I run not one but two air filtration units in my garage/shop, and of course the old reliable shop vac for general dust management.  I only use power tools for the initial roughing out of the stock material - and still the dust is overwhelming.  My conclusion relative to the dust supports your own experience!  However, since soapstone is so soft it allows me to prototype designs and work on aspects of technique.

Since obsidian and other harder material is readily available in Oregon I am striving to learn how to work with this material.  I am practicing with basswood and soapstone to develop a small (2" dia. ) ammonite replica and need to cut a few slabs of obsidian for my project.  Cutting the basic round shape from the slab is relatively straightforward, but carving the spiraling curves of the ammonite itself is presently challenging.  I need to determine how much to "oversize" my spirals in order to shape them properly.  I am trying to approximate a Fibonocci sequence in defining their progression.

Another thing I am trying to determine is the selection of a good reference point for my carving.  For example, in carving waterfowl from wood blanks one learns quickly to use the bird's bill as a reference point for scale.  I think on an ammonite one can either start at "the beginning" - which is the small circular part at the very center of the shell - or at the very end or "occupied" part of the shell.  In either case the spirals work to the opposite end in a formal sequence of curves.  Thus far working from the center out seems to make the most sense and it "feels" right to me.

Finally, your remarks on marking up the raw stone are much appreciated as well.  I use a traditional pencil for center lines and a sharpie to define basic cut  lines.  Have you tried using a special colored pen - silver, bright yellow etc. - on darker stone?  I do tend to get lost in the weeds when in comes to accuracy - part of me wants to be as realistic as possible, while part of me likes working with representation and abstraction.  Experimenting in expendable materials will hopefully help me to find my comfort zone in this regard, while fooling around with the rock itself will help me to learn more about the material and ways to work with it.

I appreciate your comments and hope you will not feel shy about offering more!

Regards, John

[Debbie K]

John:

I have used the silver marks-a-lot, but mostly the white grease pencil I mentioned above on darker stones. Also, pencil marks show up pretty well on black stones; the lines shine.

The one thing good about carving stone is that you get to make your mistakes very slowly. Sounds funny, but it's true. In wood, it's far easier to overcut. Since you know how to carve wood already,  you're going to do just fine.

Regarding where to start, I always go from large to small, so I'd start at the outside and then work down to the smaller areas. Odsidian cuts like butter (in the stone world) so you'd get a better idea of how the material works where you have more margin for error. Just go for it; obsidian is cheap and easy to procure and carve so if you mess it up it's not that big of a deal.

I have noticed that I have a little more trouble with the change in perspective or proportions in harder stone than I do with softer ones or wood. I carve a lot of faces and have noticed that I have a more difficult time with them in stone than I did in wood.

General advice: These tools will be your best friends; an inverted cone diamond bur and a diamond or tungsten steel scribe. The inverted cone makes far better curved lines than a straight bur. The scribe can be used to give you a "starter" line that your burs will follow more easily in small detailed areas than trying to use a bur alone. Both the inverted cone and the scribes can be used to undercut, which gives you the nice shadow line.

I don't know if you have used a flex-shaft very much, or rotary tools, but it's different than using hand tools. You'll adapt. I always brace my hand on the piece I carve using my little finger and ring finger as the brace which allows me to make small moves with my thumb, index and middle finger which are holding the handpiece. I found that the smaller handpiece worked better for me than the large one; I got hand cramps using the big one. I also have found that I often move the carving with my left hand against the burs rather than the other way around.

Let me know if you have any questions as you go on; I'll try to make a habit of checking every few days to see if you do; I'm also checking the "Notify me of replies" again, I hope it works this time.

Debbie

P.S. You  can make a tungsten scribe out of a broken tungsten drill bit. I ground it down on a wheel and cleaned it up on stones and bought a holder at a jewelers supply place (they have little collets and the tighten down on round tools).

Edited January 2, 2020 by Debbie K
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[Janel]

Hello John, Thank you for your introduction!

Hello Debbie and welcome back!  I am so excited to see the work that you have been doing!

Thank you both for posting about your work and what it is you hope to be doing.  Thank you Debbie for offering helpful information.

Janel

[John S]

Debbie, let me begin by apologizing to you and others for the lengthy absence from the site.  Life has gotten in the way and now the entire planet is living in fear of CO-VID 19.

Since my initial posts I have been somewhat scattered in my carving efforts.  In particular I found myself building Mathias Wandell's pantograph router.  This device allows me to rout the spiral as it naturally presents itself in ammonites.  So far I have defined the basic shape of the ammonite in wood and need to test it out on obsidian.  

I have also worked on a seated, howling wolf, using a Stiller pattern at 5 1/2" and a basswood blank.  I am carving this as a gift and I am taking pains to be as realistic as possible.  My reasoning here is to refresh my skills and knowledge thru practice, and to work with a couple of new carving burrs to get accustomed to them.  BTW thanks for the advice regarding the inverted cone bur and the scribe!  I will apply both to my efforts.

From this point forward I hope to rely upon the same notification process that you use on this site.  Hopefully a "fresh start" to posting will stimulate more involvement and activity here!

 

 

[Janel]

Hi John,

Thank you for posting about what you have been working on.  I look forward to seeing how things progress or turn out.

Janel

[Debbie K]

John:

I looked at the pantograph that you referenced but don't quite see how it will address the 3-D issue that a carving presents; a low relief, yes, but not a high relief or in-the-round one. I made a 3-D duplicator years ago using drawer slides (good ones) and a foredom. It took so long to carve with it that I never used it but for roughing in a few,  I found it faster just to carve.

Let us know how it works for you; I'm interested.

Debbie K

[John S]

Debbie, the Wandell pantograph uses either a trim router or a dremel tool as its "engine."  Thus, there is enough torque to carve swiftly if proper cutting depth is maintained.  This may require multiple passes to complete the process, which is the proper way to use a router.  I have not attempted to use my Foredom flex shaft with the pantograph but see no reason why it wouldn't work with the proper setup.

A "standard" pantograph allows one to trace along the x and y axes of the original image or object.  The Wandell pantograph is hinged at the arm base thereby allowing the device to "rise and fall" naturally with the contours of the object, thus taking into consideration the third or "theta" axis. This should permit carving in relief, as well as in the round.   I have yet to try working in three dimensions with it but will eventually try to do so.

The Wandell pantograph is set up to reproduce images at either 1/2 or 1/3 actual size.  Thus, if you want a 5" final product you need a 10" image to work from - otherwise the final will be 2 1/2. "  I addressed this by adding an " image screen" by placing a piece of plexiglass over the pattern and running the stylus over that surface.  The result is a smoother, almost effortless trace of the pattern.  I can better explain this with a few photos which I will provide if helpful.

So far I have cut an ammonite image as well as that of a monarch butterfly.  I hope to inlay the orange and white patterns of the butterfly wings into a black wing, and I hope to create the body of the insect with my fly tying equipment.  It may take a while to acquire the thin, colored veneer that is needed for this project.  My wife and I are in the high risk category and currently "sheltering in place" so I have an abundance of time to play with.

Mathias also offers plans for a 1:1 pantarouter which I may add to my equipment later.

Stay healthy, and stay in touch!

John