Here's a Trini Lopez Deluxe that spent way too much time in its case. I'm guessing that guard will fall apart if you touch it.
The plastic that was used on some older Gibsons is downright dangerous. It is essentially a solid explosive that’s been stabilized. The trouble is that it doesn’t always stay that way. It’s a process called off gassing. Also called out gassing and gassing off. And it’s as bad as it sounds. As it turns out, the plastics that were used for certain components back in the 50s and 60s were not terribly stable from a chemical standpoint. Disclaimer: Don’t know much about chemistry. That said, it’s pretty straightforward. I’ve written about shrunken tuner tips and most of you have seen them but that isn’t all. Have you ever seen a 355 with the pickguard completely disintegrated and all the gold parts corroded and green? It’s not a pretty sight and it’s not something that you can simply wipe away like tarnish. This stuff actually eats the metal and plastic parts. This comes from a site called “The Museum of Jurassic Technology”
In 1868 John Wesley Hyatt formed a substance from a homogeneous colloidal dispersion of nitric acid, sulphuric acid, cotton fibers, and camphor. It was a substance of great tensile strength capable of resisting the effects of water, oils, and even diluted acids. Hyatt’s brother called it celluloid, and it became the first commercially successful synthetic plastic. It was cost-effective to manufacture and could be produced in a variety of attractive colors. Heated until soft and molded into shapes, it became a substitute for products fashioned out of ivory, tortoiseshell, and horn. Perhaps it is best known for its use in motion-picture film, where its volatility has resulted in the destruction of a vast percentage of early footage. But it was also used to fashion removable collars, collar stays, knife handles, guitar picks, piano keys, billiard balls, and, of course, dice.
Also pickguards and other plastic guitar components. The problem actually has a couple of components. The first problem is the disintegration of the plastic itself. But the real destruction comes from the gasses that the process of disintegration emits. If the guitar is stored on a guitar stand or a wall hanger, the gasses pretty much dissipate harmlessly into the air. The problem is that most guitars are stored in the case with the lid shut tight. Sometimes for decades without being opened. So what is this stuff? Well, apparently, it’s nitric acid. If you remember high school chemistry, nitric acid was one of the things the teacher didn’t let you use in the lab without a bunch of protective gear like heavy rubber gloves, goggles and stainless steel tools. They probably don’t let students anywhere near it anymore in these politically correct times. Nitric acid will eat the hardware-including the frets-of a guitar that’s in the case with an off gassing pickguard. It will also damage the nitrocellulose lacquer (which is chemically similar) finish. The cautionary tale here is that if you’re a collector who stores his guitars and rarely plays them, you might want to open the case once in a while and let the gasses out. I’ve read that celluloid can be completely stable for decades and, suddenly, completely come apart chemically over a very short period (like weeks). It doesn’t warn you either. It’s more like a time bomb that doesn’t have a countdown. Yikes.
These tuners are also an example of off gassing. These were on my red 59 ES-345 and for some quirky reason, only 5 of them shrunk. I don't think the tuner tips are celluloid but gassing off isn't limited to celluloid. Almost any plastic can gas off. Some do serious damage and others don't. Want more info? Call a chemist.