Full Chisel Blog

July 29, 2009

Working with Bone and Ivory

Is just about the same, ivory is a little harder and does not contain vessel pours like bone.  Ivory comes from elephants, whales teeth, narwhal and walrus tusks, elk teeth (the two bugle teeth) and fossil ivory from mammoths and other large extinct beasts.

I am not promoting the use of ivory, in many cases the animals are protected, except mastodons and trade in new ivory is illegal.  I have however recycled a couple of piano’s and got quantities of heads and tails from carefully removing them from old pianoforte’s.  The method for working ivory is the same as bone.  It can be worked with normal woodworking tools, it requires a fine toothed blade to saw to prevent chipping.  To make a hole I drill from both sides to prevent chipping when the bit exits.

Bones are obtained from the skeletons of animals, the larger the better.  Some bones are just the right shape, buffalo or bison rib bones makes excellent handles for crook knives and their knee caps were used by Native Americans as a paint brush.  The patella is quite porous.  Leg bones, ribs and shoulder blades are excellent sources of bone.

It is best to get bone that has not been cooked, like those nice rings from the middle of center cut ham, great for ferrules, by the way.  Cooking like kiln drying makes the bones brittle.  The bones can be cleaned by gently boiling them, or they can be placed on an ant hill or out in the garden and little creatures will clean the bone over a few weeks.  Secure the bones so they can’t be carried away by larger creatures.

Here are the bone folders that are commercially available.

I use a couple of files and a card scraper to get to this point (below).  I use a coping saw with a fine fret blade to cut off the point of the round end bone folder.    These are after a bit of work with a file and scraper.  One has a standard round handle the other has a coffin handle.

I also checker the handles with a flat file on edge.  I do the layout with a lead pencil then use the sharp edge of the file to make the groove, which I try and do in one pass.

I was told the stuff that fills the engraving or checkering is called niello, although its general term is an alloy of metal that is put in the engraving to make them contrast.  The red stain is cochineal.

The hand buffer on the right is after one in the Dominy Workshop from New York, now in the Henry Francis du Pont Winterthur Museum.  It is poplar with horsehide, flesh side out mounted with brass tacks.  It has no padding under the leather.  I use white rouge as a buffing compound added to the buffer’s leather.

Bone is basically minerals like calcium and collagen (a source of Hide Glue) and it can be manipulated by boiling and or soaking in vinegar.  Soaking in vinegar will soften the bone by removing some of the calcium.  When wet it can be easily carved and even bent, and when it dries it becomes hard once again.  It will not be as hard as it was originally but it will harden up.

I save all of the shavings and dust from bone to use as bone flour to thicken Hide Glue.  I also keep Ivory dust when I work it and carefully save all in a small bottle.  I will some day toast it and make some burnt ivory black pigment, common in the nineteenth century but unavailable today.

It can be stained with a variety of materials, some take better than others.  It can also be bleached white.

Stephen

2 Comments »

  1. Hi Stephen,

    Great article. I was just wondering if you had any tips on using a hot chisel with bone? I’ve seen some work before and want to learn more about it, it seems like whatever there is to use, something like a souldering iron I suspect, that there is a type of gun, or tool that comes with multiple size tips? Any suggestions you might have, or indeed the name of this process would be greatly appreciated.

    -Jake

    Comment by Jacob — March 20, 2014 @ 8:19 am

  2. Jake,
    Good question to which I have no answer, I’ll do some research. My suggestion would be to use adequate ventilation and even working bone or ivory cold can stink.

    Stephen

    Comment by Stephen Shepherd — March 20, 2014 @ 8:45 am

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