As computers like the venerable breadbox Commodore 64 age, their plastic doesn’t just turn increasing shades of yellow and brown, the ABS plastic also tends to get brittle. This is a problem that seems to plague many plastic cases and enclosures, but fortunately there are some ways to halt or even reverse the heavy toll of time, with the [More Fun Making It] YouTube channel exploring a number of methods, including UV-curable resin, PETG 3D-printed clips and silicone molds.
Aside from large-scale damage, screw posts tend to snap off a lot, either during shipping or when merely trying to open the case. The same is true for the clips around the edge of the C64 case, which rarely survive that long. Gluing a case clip back on with epoxy or such somewhat works, but is messy and not that durable.
Instead UV resin is used, together with newly printed clips in translucent PETG. The remnants of the old clips are removed, followed by the application of the resin. The clips are actually a modified version of a VIC-20 case clip design by [Ken Mills]. With the UV resin as glue, curing is almost instant with a UV lamp unlike the tedious process with epoxy.
In the case of screw posts the alternative to just re-gluing was initially clear tape as a mold and UV resin, but this got improved with making a mold of an intact post from kitchen-style silicone and corn flour. This mold is placed around the busted post and resin poured in before curing. A new thread can then be created in a drilled-out hole with liquid resin around a screw, though we imagine that one could of course try running a tap through the cured resin as well.
A big challenge for the mold was to create an entire screw post from scratch, which required poring in many layers of resin and curing them, which is probably more tedious than 3D printing a new one. That said, it does seem to work, and it’s not that dissimilar from the resin used with SLA 3D printers, all of which are photopolymers. Without a clear idea of what exact photopolymer is inside the bottle, results may obviously vary.
Finally, resin was also used to try and glue part of the enclosure back together, and a viewer appears to have repaired a terminal whose case got shattered by the tender care of the parcel system using UV resin with good results. Of course, if your system’s case has been basically pulverized as in the case of [LGR]’s laptop, then printing a new case might be the more sensible option.
Thanks to [Petrik77] for the tip.