Organic solvents, commonly sold as "citrus oil" cleaners, and naptha, sold as "old-fashioned" cigarette lighter fluid (like you would use in a Zippo) will take off almost any sticker, usually quickly. If the adhesive has been dried out for decades, it may take more time and soaking, which greatly increases the chance of damaging the plastic.
ABS and PBT generally hold up pretty well to naptha ("lighter fluid"). Sometimes naptha isn't aggressive enough, but just give it more time and/or use a soft plastic brush to work it into the old glue. Do not use products that contain xylene, like "Goof Off". Xylene will attack ABS very quickly as does acetone, toluene, and MEK (found in lacquer thinner).
The only Gum-Out I know is a carburetor cleaner, and that is probably too strong, but would probably work.
Lighter fluid only costs a couple of bucks at the pharmacy or Wal-Mart, and works well on PBT if you are fast and careful. On ABS be even faster and more careful, and test first.
I'll be honest, I have a lot more of these to get through than just 2 or 3...I guess it's time to get started.
When I referred to PBT I was talking about parts in general, not cases specifically.
The Model F plastic is so much more rigid and brittle than the Model M case, I assumed that it had to be a dramatically different composition. Also, it has that "skin" that is so easily damaged.
Although I love Model Fs, the case material is one area that was significantly improved with the M.
I'll be honest, I have a lot more of these to get through than just 2 or 3...I guess it's time to get started.Show Image(http://goput.it/n7c.jpg)
Indeed, ABS gets more brittle with age, especially when exposed to UV. However, ABS is just a general term for a type of thermoplastic. There are many ways to adjust its behavior when it is formed along with many additives and techniques used to augment various properties. There is definitely something fundamentally different between the Model F and Model M cases. I have had many Ms of different ages and even the oldest M is nowhere near as brittle as any F I have ever touched. In fact, a brand new Unicomp case is much more brittle than an almost 30 year old M, even though both are ABS. I wish Unicomp would spring for the nicer materials. Their products would have a much higher quality feel to them. :(
Holy crap....where did you get all of those Fs?
Holy crap....where did you get all of those Fs?
Someone had them stored in a barn on shelving, so some are somewhat clean, others are horrible, it depends on where they were on the shelves. It was a take everything or nothing at all, so I also have two IBM 5150s, a XT, two P70s and a couple other random systems.
two P70s