Trouble With Celluloid By Prof. Roland Phlip
Celluloid is a man-made material that was commonly used for knife handles in the early 1900s.
Celluloid often looks like modern plastic. It can be made clear, many different colors, or even have swirled patterns in it. It can be made opaque, translucent, or transparent. It can even be made to resemble ivory or mother of pearl. Occationally, bits of metal or other materials are suspended in it for extra decoration.
Unfortunately, celluloid is fatally flawed. It is chemically unstable. It shrinks with age and it breaks down over time, especially with heat, and UV light exposure (such as sun light). When celluloid breaks down, it discolors, cracks, and eventually crumbles. Worse than that, though, it releases very corrosive gases which can rust the blade of the knife in question or any knives stored nearby. These gases are quite powerful. In a closed container full of knives, one bad apple can really spoil the whole bunch.
Here at The Institute for Advanced Balisong Studies, most of our extensive balisong collection is kept in bank deposit boxes, small, very closed containers, so, we have very few with celluloid handles. Since knives with celluloid handles would be almost certainly from the early 1900s, very old for a balisong, one of our major collecting goals, this has caused us to turn down some really great pieces.
The exact chemical process of celluloid's breakdown is not well understood. There is considerable debate about what causes it and what types of celluloid are more likely to undergo such deterioration. In this day and age of engineered plastics, celluloid, which is expensive, difficult to work with, also quite flamable, is hardly used anymore. So, the breakdown of celluloid isn't the sort of thing that the government awards huge grants to study.
Nobody has made celluloid material in the US for at least fifty years. There's still one factory making it in small quantities in Germany. A few knife makers still use it.
Celluloid is highly flamable and celluloid dust is highly explosive. So, very few knife manufacturers or custom makers use what little celluloid is still being made.
While UV light such as sun light and heat are both thought to accellerate celluloid's decomposition process, they are not necessary. Keeping celluloid-handled knives in dark and/or cold places is no guarantee that they won't deteriorate. Storing them in an inert atmosphere might help, but that's complicated and expensive and best left to museums.
You can read all about celluloid's problems in this most excellent article from the Oregon Knife Collector's Association Knewletter.
Consider, also, the following post that appeared recently in the Usenet newsgroup rec.knives with the subject "Fighting Rooster Celluloid Knives, Rust Time Bombs!"
"Mike W." wrote:
I opened a knife roll that has sat in the top of a closet for about 4
years, WOW. I couldn't believe how quickley the Fighting Rooster
celluloid knives had turned into so much useless garbage. I can't
imagine how I would have felt if I'd had these placed with my old
Remingtons, or Case Tested knives, I'd be wanting to hang someone.
Celluloid handles often deteriorate very quickly and with no warning. It's not uncommon to hear collectors say, "I've had those knives for decades and they've been perfectly stable. I looked at those knives less than a year ago and they were fine. But, when I looked the other day, the celluloid was crumbling and the blades and liners were hopelessly rusted." The fact that a piece of celluloid is in perfect condition and has been stable for decades is no guarantee that it won't go bad any day now.
It's also common to hear of whole collections going bad at the same time. Apparently, the gas emitted from the first one can trigger and accelerate the process in the others.
If you have any knives or other items (celluloid was also common on custume jewlery, pens, and other decorative objects of the same era) with celluloid, I urge you to keep them separate from the rest of your collection and not to store them in closed containers.
Here at The Institute for Advanced Balisong Studies, we do not normally recommend making any modifications to collectible knives. Just about anything you could do will lower the value of the knife. But, if you have collectible knives with celluloid handles or inserts, we do suggest having a qualified craftsman remove the celluloid and replace it with a modern material before the deterioration of the celluloid ruins the knife completely. The original celluloid pieces can be retained and stored elsewhere.