I've got a razor I'm restoring that has what look to be bone scales, but I'm not entirely sure. How can you tell/test for bone?
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I've got a razor I'm restoring that has what look to be bone scales, but I'm not entirely sure. How can you tell/test for bone?
Bone usually has pores from blood vessels.
One way to recognize bone is to grasp each end with pliers and twist until it breaks. A synthetic material will crack or shatter, while bone will splinter in a spiral fracture with the most pleasing crunchy sounds.
lol.
Seriously, the thing about pores from blood vessels is okay, but that can be hard to spot depending on how it was finished.
Try that, but also remember that bone is made up of fibers of calcium and phosphorus, so it will have a grain to it. This can also be hard to spot depending on the finish, but will probably be a lot more obvious if you get some good light and look in between the scales to see what the unfinished texture looks like.
Ultimately, even the best synthetic bone handles are still plastic, and when you hold them, they won't feel like something that was once living the way bone will.
You can hot pin test it too. Get a pin red hot & touch it to an inconspicuous area (inside the scales). If it melts, it's synthetic. If not, it's either bone or ivory. Then you need to look at the structure to tell these two apart. As mentioned, bone will have pores. If you've got a loupe or something that will make them easier to see.
Give it a light sand. Won't tell you if its bone or ivory but the celluloid smell of camphor can be eliminated.
Bone will likely look more porous than ivory under magnification also.
The pores in bone scales are usually most evident at the top and bottom ends - in old handles the pores get filled with dirt, and because they were once the site of blood vessels they penetrate the bone and anything but the most superficial soiling is nigh impossible to clean or sand away. Bone also often has blotchy discolourations.
If the scales don't fail the pin test, they could be ivory or bone. Ivory has a grain pattern running along it, and another (often very hard to see) pattern running at right angles. Ivory is usually a more regular colour than bone, and it doesn't have the grime-filled pores in it like bone.
So, if its old, a bit soiled and has little dark dots near the pivot and wedge end it is probably bone. It's usually quite thin too, and most I have seen have thin metal (lead? pewter?) wedges. Same goes for ivory, however.
Other than that, what Ben said.
Regards,
Neil
Are there no awesome tricks for cleaning discoloration from bone scales?Quote:
Originally Posted by Neil Miller
Also, once you have bone cleaned (as much as you can) and sanded smooth, should one finish it with some sort of sealant or leave it natural? Seems like finishing would prevent further soiling, but would take away from the feel bone has...
When it was originally prepared, the bone was de-greased. If the degreasing wasn't deep enough the fat remaining in the bone migrates to the surface over time and makes it go yellow and discoloured. People usually think of bleach first, but this is destructive and make the bone go powdery and friable - talking about chlorine-based bleaches here.
Something gentler is hydrogen peroxide - you could give that a try. Swab it on and work it in with cotton balls, dont soak the piece in it. Abnother possibility is lemon juice and salt. I used both, but with very limited success.
The main trouble I found was the pores - after cleaning, if you buff them with anything that darkens in colour, they will go dark again - presuming you can get them clean in the first paste. I used toothpaste - it's lightly abrasive and restores a bit of shine, and its white. but it will go into the pores and eventually oxidise and discolour. Maybe some sort of waxing afterwards would help, but I don't really know.
Regards,
Neil
Thanks for the replies everyone. As soon as I find a pin, I'll be trying out the hot pin test. I'm really starting to think it might be bone or ivory, but I want to make sure. I'd hate to sell this at celluloid prices if it's worth more!
Anything thin will do - even a paperclip opened out - just heat the end of it to red and touch somewhere inconspicuous - maybe between the scales on the inside. If it doesn't melt it may be bone or ivory, if it smells a bit like when the dentist drills teeth its ivory.
Regards,
Neil
lets see a pic!
Quote:
Originally Posted by ben.mid
Good tip, but please don't try this if you even think you may have celluloid scales. Celluloid is highly flammable!
I'll try for the pic, but I'm having camera issues at the moment.:rant:
I use neatsfoot oil as a final conditioner on animal based scales. Not a sealant but its made from horn & hoof etc so seemed a good idea :)Quote:
Originally Posted by jakoblah
Yes, it is.Quote:
Originally Posted by Casey302
Here's the little used "Flame Test" I'm not sure a hot pin can induce it though!
YouTube - Celluloid Scales Flame Testing
That's my video :D
I wasn't performing a flame test, rather demonstrating why flame testing is a bad idea.
Celluloid is nitrocellulose, which is the main propellant used in smallarms ammunition. I really wouldn't be too sure that a red hot paperclip wouldn't ignite it, it might not, but I wouldn't be the least bit surprised if it did.
Watch the video again. The lighter I used was almost out of gas and the flame was very feeble. I barely put it near the celluloid and it caught so easily that it made me jump/
The scales that I did this heinous thing to were from a razor called 'The Velvet Glider'. It was a travel razor with unusual scales that formed a self contained case for the razor.
Luckily they were splintered and cracked way beyond repair. I say luckily because they were absolutely hideous, but if they had been in salvageable condition I wouldn't have been able to do this to them :D
The blade is now restored and sitting in some nice conventional (and non flammable) scales.
On a side note, shirt collars used to be made of celluloid, imagine how serious an accident by a careless smoker would have been. Celloloid is pyrotechnic, meaning it creates its own source of oxygen during the combustion process, it is very difficult to extinguish.