Thread: question on scales

I know this must have been asked before but can't find it, how can you tell the difference between different scale materials (cellulose, bakelite, bone etc) and what is the hot pin test, if there is already a thread or sticky with this info point in that direction and I will go way humbled and quite

the pin test is done by heating up an ordinary pin with a flame, then touch it to the scale (preferably the inside o you dont see the mark). You can tell the material by the smell, horn is kinda burnt hair like. plastic will melt and smell like plastic. Its hard to explain...thats all i can help with sorry, im sure some one will chime in with better info.

The hot pin test is usually used to tell bone from ivory. Usually bone has a distinct look to it and ivory has a fine grain to it. Celluloid is unstable stuff and if you rub it it will emit a vinnegar like smell. Plastic or bakelite is usually very shiny and if you rub it it won't smell at all. A hot pin on celluloid will ruin it and on plastic will burn a hole through it.

Good (fresh or well preserved) celluloid smells like camphor when rubbed hard.
Bad (stale) celluloid smells like vinegar when rubbed hard. Transparent and light color scales will be stained reddish brown .

When you prick the horn with the hot pin it will also sometimes make a fizzing sound (scream).

Bakelite is hard, brittle, has no smell, not affected by hot pin, usually comes in black, careful when pinning... it will brake.

There is another kind of plastic its a more modern thermoplastic found on some razors.
I forget the name, is brittle, will be stained a milky white coat when dipped in hot (boiling) water (usually discovered when trying to straighten warped scale). Hot pin will melt the material, produce little smoke and no smell.

Hope this helps my friend

Thanks for the help guys