[Mark]

HI everyone. This is my first post. This is my first attempt at carving ivory. I purchased a piece of hippo ivory and have cut it to a smaller length for my piece. About half of the tooth has the nice ready to go Ivory that is manageable to carve. However about half the tooth has a harder grooved outer layer that is really hard to carve. Does anyone know of an easier method of removing this hard outer layer to get to the chewy easier to carve center? Thanks and any help greatly appreciated. Mark Lustigm@verizon.net

[Mike Ruslander]

As I understand it, you want to remove the bark. A belt sander, using the slack part of the belt should help get rid of the outer layer. Start with a medium grit and watch the aggressiveness. I'd hand sand with the finer grits to avoid burning the material. You could hand sand entirely, but it will take longer. Hope this helps.

[tsterling]

The hard part is the enamel of the tooth - what you want to carve is the interior ivory or dentin. I soak the tooth for about 30 minutes in muriatic acid (used in the construction industry for cleaning concrete and brickwork - is an industrial grade of hydrochloric acid). The acid will dissolve the enamel. Obviously the acid is a hazardous material, so you should handle it with care, outside, rubber gloves and eye protection. Don't leave the acid inside your studio/shop since outgassing will cause all the steel in the place to rust, even with the cap sealed.

The bad part is the surface of the ivory will be attacked as well, and will be sort of gooey/sticky. I use a scraper to remove all of that and get down to the good carving material, followed by a short soak in baking soda/water or household cleaning ammonia to neutralize any remaining acid. Ideally, you should wait several days before continuing to carve. Any gooey spots you've missed should show up as darker areas by then.

Don't try to cut the ivory with the enamel still on with any power saw - the enamel will ruin the blade, as my bandsaw can attest.

Power sanders can slowly remove this very thick enamel, but you need to be careful about heat buildup, as this will ruin the immediate ivory layer underneath. Don't breathe the dust this will produce...

[Mark]

tsterling, on Sep 21 2007, 12:22 AM, said:

The hard part is the enamel of the tooth - what you want to carve is the interior ivory or dentin. I soak the tooth for about 30 minutes in muriatic acid (used in the construction industry for cleaning concrete and brickwork - is an industrial grade of hydrochloric acid). The acid will dissolve the enamel. Obviously the acid is a hazardous material, so you should handle it with care, outside, rubber gloves and eye protection. Don't leave the acid inside your studio/shop since outgassing will cause all the steel in the place to rust, even with the cap sealed.

The bad part is the surface of the ivory will be attacked as well, and will be sort of gooey/sticky. I use a scraper to remove all of that and get down to the good carving material, followed by a short soak in baking soda/water or household cleaning ammonia to neutralize any remaining acid. Ideally, you should wait several days before continuing to carve. Any gooey spots you've missed should show up as darker areas by then.

Don't try to cut the ivory with the enamel still on with any power saw - the enamel will ruin the blade, as my bandsaw can attest.

Power sanders can slowly remove this very thick enamel, but you need to be careful about heat buildup, as this will ruin the immediate ivory layer underneath. Don't breathe the dust this will produce...

Thanks very much Tom. I am on the way to get some acid and a replacement Dremel bit or 2. Thanks for making a tough job easier. Once I start carving, I will be posting progress. Mark

[Doug Sanders]

While we're on the subject, does the same go for boar's tusks...removal of the enamel and all. I've never worked on one, but I've got a few 'raw' ones laying about. Won't removal of the enamel leave you with very little to carve? Porcinely speaking.

[b_art79]

Hello people,
hope you can get some help out of this instruction
did not read it yet but it looks good...

http://www.boonetrad...structions.html

Cheers Bart

[Hyllyn]

tsterling, on Sep 21 2007, 05:22 AM, said:

Power sanders can slowly remove this very thick enamel, but you need to be careful about heat buildup, as this will ruin the immediate ivory layer underneath. Don't breathe the dust this will produce...

Tom pointed those very important issues and although Clive's solution seem to be the easiest and most likely best to keep the material intact do bear in mind that most enamel and dentin matrix of most teeth in the animal world is hydroxilapatite (a.k.a hydroxiapatite) and that reads pretty much a calcium phosphate ceramic. It's certainly not silica but if you breathe it the mucose of your lungs and sinuses won't like it very much and might cause chronic problems if you sustain exposure to it for long enough. So if you plan on working often with it it's probably wiser to weaken it with muriatic acid, fluoride concentrated solutions will also cause it to break in bits as it does with teeth when they are in mouth but on a hippo tooth it could certainly take a while longer.

As for having enough material to carve after the proceedure it should not be a problem, most dentin to enamel ratio in provide for plenty leftover.

Sorry about the dentistry insight, it is perhaps the only bit I can talk about with more knowledge at the moment.

Regards

[Hyllyn]

Well of course, it is about equality amongst everyone and for everyone (but him), and if you refer to the zoo that would probably be another name for his government cabinet, so most likely that hippo would probably be the minister of education hahahaha.