Bright Again
Like many old plastic cases, also this old-timer's exterior suffered from severe yellowing, which was already slowly turning olive brown. This made the Sharp a natural fit as guinea pig for the miracle cure Retr0bright!
Retr0bright paste was applied to the various surfaces of the top of the case and then exposed to UV light for up to three days (with occasional brushing). Unfortunately, due to the gel drying out, some blooming occurred in some places (e.g., the gray-brown area around the monitor cutout), but with a little patience and scouring paste, this could be removed to some extent. However, it should be noted that the printed Sharp logo and the lettering on the data recorder keys have suffered some damage – despite my efforts to scrub around them as much as possible.
The keycaps were incubated in a homemade shaker bath – and some of them even had to serve as subjects for a few experiments on the chemistry behind the Retr0bright process.
The keyboard couldn't be restored 100% perfectly – as a closer look reveals, some of the prints have faded to varying degrees. This may be related to the different (and sometimes multiple) treatments of the keys with different incubation solutions during the aforementioned experiments.
Despite these minor flaws, I think this classic computer has gained a lot of appeal thanks to the Retr0bright treatment!