Reproduction ivory look hand grips

This make interesting [albeit disturbing] reading: **LINK**

https://www.nationalgeographic.com/animals/article/giant-clams-are-being-stolen-and-carved-like-ivory

MichaelG.

Camel bone is what I use and It's available in fairly substantial sections. Any bone needs to be de-fatted. Don't use bone from the butchers unless you treat it yourself as the trapped fats and other tissue goes rancid and is not hygienic.

Commercial de-fatted (treated) camel bone can be go from luthiers suppliers (its used to make sitar parts - especially the jawari bridge) as well as being used to make knife scales.

It has a good colour, is hard and machines well. It takes a really good polish. It also stains very well - I use the Konig stains to match the colour of new parts to existing old ones.

I think it's not vinegar but glacial acetic acid which is much nastier stuff. Other sources suggest soaking in sulphuric acid then boiling in the same, but someone who tried it said he just ended up with a sour soft boiled spud. Glacial acetic would make sense as it extracts water and also turns cellulose into cellulose acetate ("celluloid". Also could be done with nitric but that is cellulose nitrate which is highly inflammable. As always, Google is your friend.

Celluloid is indeed cellulose nitrate. Just remember that if ever you need to clout a pre-WW2 steering wheel ...

Tim

Had a quick look in my Chemistry books, only one of which gives directions for Cellulose Acetate. It doesn't involve potatoes!

Problem with spuds is they contain a lot of impurities in addition to cellulose, so the first step is to get rid of them. I suggest boiling and mashing with dilute caustic soda to get rid of the starch and any oils or gums. The solid residue left after washing in cold water will be mostly Cellulose. It also needs to be dried.

Cellulose reacts with strong Acetic Acid to make the ester Cellulose Acetate but the reaction is slow and inefficient. For efficiency, my book suggests using a mix of Glacial Acetic Acid and Acetic Anhydride with a dash of concentrated Sulphuric Acid. The recommended source of Cellulose is Cotton Wool, which is almost completely pure.

0.5g Cotton Wool + 10ml Glacial Acetic Acid + 10ml Acetic Anhydride + 1ml conc Sulphuric Acid

This reaction is quick, clean and high yield, but the ester would have to be processed further with a plasticiser like dibutyl phthalate to make it look like Ivory.

I think mixing potato with vinegar would produce tiny quantities of Cellulose Acetate very slowly, but any ester will be thoroughly polluted with unreacted spud - a dirty wet mess. Purifying the ester is possible but expensive - it involves dissolving it in an Ammoniacal solution of Cupric Oxide, and then precipitating in a dilute acid.

Easier and cheaper to buy plastic that looks like Ivory than to make it yourself.

Dave