Is This Celluloid?

Trout Hound

Trout Hound

Joined
Sep 28, 2014
Messages
693
Howdy Friends,

Awhile back, my mom unearthed this old Ulster peanut that had been hers as a Girl Scout many years ago. She asked if I could clean it up for her. Can anyone tell me for sure whether or not these are celluloid handles? They look more like delrin to me, but I’ve never handled celluloid in person, so I just want to be sure. If anyone knows a model number or production date, all the better! I appreciate the help. Thanks!

TH

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I haven't seen Del shrink like that.
Some yellow bone or micarta would look nice...depending on how much of a clean up job you feel like doing.
Whats the other side like.?....could this be sun damage...like if it sat on one side on a shelf in the sun...for instance...I have a white del Schrade ...one side is badly faded from that but the other is still good.
 
Hard to say.
The shrinkage, pattern of discoloration on the blades (mostly along the spines) the discoloration of the shield, pins, and bolsters suggests celluloid to me.

That said, it is possible that the covers aren't shrunk and the knife has always had the gaps at the covers/bolsters.
As for the discoloration of the shield, pins, and bolsters, that might just be normal tarnish from use.
The lack of discoloration on the pile side of the main blade suggests the covers are not celluloid.

What do the backsprings and liners look like?

Have you vigorously rubbed the covers with a dry rag and given them a sniff?
Trust me: You'll know if they are celluloid from the stench.
 
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This looks like their 183Y model from the late 50's so I would say it is not cell and not Delrin... likely a more stable plastic like a styrene of some sort. The catalog just calls it out as "Maize "Yellow" Plastic". I have some of their other "plastic" handle knives and the "fit" of the plastic was pretty bad / shoddy work but it does appear to have some shrinkage too. Ulster was struggling post WWII and the craftsmanship was not impressive in the late 50's up until the early 70's when they shut down.

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tongueriver said:
I will defer to Kevin on this one; I would have called it cell. One thing is for sure; it is NOT Delrin.
Click to expand...

Agree with that.

veitsi_poika said:
This looks like their 183Y model from the late 50's so I would say it is not cell and not Delrin... likely a more stable plastic like a styrene of some sort. The catalog just calls it out as "Maize "Yellow" Plastic". I have some of their other "plastic" handle knives and the "fit" of the plastic was pretty bad / shoddy work but it does appear to have some shrinkage too. Ulster was struggling post WWII and the craftsmanship was not impressive in the late 50's up until the early 70's when they shut down.
Click to expand...

Delrin was not put into commercial production until the early 60's. So if the knife is from the late 50's, it isn't Delrin.

https://www.bladeforums.com/threads/dupont-delrin-staglon-research.439751/
Early plastic handles were a type of styrene. Styrene is more stable than celluloid, and cheaper than imported antler to produce and assemble, but still not both hard and completely dimensionally stable.
Click to expand...

So, likely Styrene.
 
afishhunter said:
Hard to say.
The shrinkage, pattern of discoloration on the blades (mostly along the spines) the discoloration of the shield, pins, and bolsters suggests celluloid to me.

That said, it is possible that the covers aren't shrunk and the knife has always had the gaps at the covers/bolsters.
As for the discoloration of the shield, pins, and bolsters, that might just be normal tarnish from use.
The lack of discoloration on the pile side of the main blade suggests the covers are not celluloid.

What do the backsprings and liners look like?

Have you vigorously rubbed the covers with a dry rag and given them a sniff?
Trust me: You'll know if they are celluloid from the stench.
Click to expand...

Thanks very much for the info. I tried rubbing it hard with a rag, and it just smelled faintly of plastic. Is it safe to assume, then, that this is not celluloid, and that no special precautions need to be taken for storage? Thanks.
 
Trout Hound said:
Thanks very much for the info. I tried rubbing it hard with a rag, and it just smelled faintly of plastic. Is it safe to assume, then, that this is not celluloid, and that no special precautions need to be taken for storage? Thanks.
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Celluloid smells like acid.

The covers are likely Styrene, as stated above. No special storage precautions needed.
 
Trout Hound said:
Thanks very much for the info. I tried rubbing it hard with a rag, and it just smelled faintly of plastic...
Click to expand...

If you rub it until it gets hot, or run very hot water over it, and it smells like plastic, it's plastic. If you do the same and it smells like camphor or mothballs it's celluloid. If it smells like formaldehyde it's Bakelite.

Many plastics shrink over time, so shrinkage alone isn't a sure-fire indicator of celluloid.

For some reason any time someone thinks of plastic and knives at the same time, Delrin is the automatic answer. Almost any plastic that is reasonably hard has been used as scales at one time or another.
 
For future reference there is one pretty easy way to tell if something is celluloid. If you touch your tongue to celluloid you will feel a burning sensation (not painful) that you won't get from any other knife handle material. This pretty much seals the deal. I may have done it a time or two, but if you tell anybody I touched some old celluloid with my tongue I will deny it up and down.
 
Trout Hound said:
Thanks very much for the info. I tried rubbing it hard with a rag, and it just smelled faintly of plastic. Is it safe to assume, then, that this is not celluloid, and that no special precautions need to be taken for storage? Thanks.
Click to expand...
Any plastic is sensitive to light, heat, humidity, etc. so I still keep all of my plastic handled knives in an open top box/container in a cool, dry area and away from any windows. Your knife has made it 50+ years probably stored in a drawer somewhere so I'm guessing you're fine for another 50;)
 
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