Why Your SNES Turned Yellow

If, back in the day, you ever wondered why your old Super Nintendo tended to discolor, your curiosity will now be sated. Via Ars Technica's Opposable Thumbs blog, an article on the Vintage Computing and Gaming site which explains the mysteries of plastic discoloration. From the article: "Since ... different batches of plastics had ... different aging results ... then there must have been a difference of additives between them. Perhaps in one of the production runs of plastic, they didn't get the catalyst or flame retardant mixture quite right and more residues were left over in the top half's plastic batch, thus causing it to degrade more rapidly over time. And by the time Nintendo produced the later runs of Super Nintendos, they had perfected the manufacturing process of their plastic, meaning that those later models aren't as susceptible to oxidation as the earlier models are."

huh....

[Criliric]

I guess that explains why my old monitors turned that ugly yellow... thanks.

Discolouration

[FirienFirien]

You get the same with a huge number of materials; the problem is that the additives don't complement each other well: if you want flame retardant, you get something that oxidises with light more easily. If you want super-white white, then the damn thing melts if vaguely near a flame. I had to do some research on this about a year ago - it's even worse with fabrics. I think there may be more expensive materials that balance the two better - but then you add expense to the case. You can have superwhite and then top it off with a layer of something tough and clear, but then you need to bind the two materials and create extra manufacturing cost from having thinner slices and having to put them together. Or - like the current trend - you can pick a colour that's not such a pain in the ass.

Infra red reveals the truth...

[Dogtanian]

I noticed a while back that (amongst other things) my Atari 800XL [smithore.com] (not my photo) had yellowed badly, but that the 1050 disk drive [zock.com] (again, not mine), which was part of the same bundle and appeared to use the same beige plastic still looked "as new". I doubt varying exposure to daylight could account for all of this.

Interestingly, my year-old keyboard has a white plastic case and keys. However, plastics that appear identical [imageshack.us] to the naked eye, aren't always so similar when viewed with IR [imageshack.us].

Re:Don't need sunlight... or smoke...

[Anonymous Coward]

The article clearly mentions that sunlight is only one possible cause for a certain type of plastic with certain additives.

Simple exposure to oxygen or heat can cause yellowing too over time. And in your case, it's possible that the clear plastic packaging degraded and outgassed nasty chemicals that could have accelerated the aging of your plane.