exxos's Atari, Amiga & retro forum

PhilC wrote: 10 Nov 2021 09:50 This is the C64C all back together after it's clean.

It needs a good dose of retrobrite, especially the two tone yellow keys. Then the rear case clips will need fixing as all of them are broken.

I actually have no idea what I plan to do with this C64 as I bought it on a bit of a whim and already have two others.

The differences between machines is quite surprising to me, I have a similar C64 and it's definitely paler and less yellowed than yours. Similarly, I have an Atari 65XE that is as fresh as the day I bought it, yet I have seen others that are super yellow and it's clearly a different plastic to the STs, which also vary wildly in their yellowing.

rubber_jonnie wrote: 10 Nov 2021 10:47
The differences between machines is quite surprising to me, I have a similar C64 and it's definitely paler and less yellowed than yours. Similarly, I have an Atari 65XE that is as fresh as the day I bought it, yet I have seen others that are super yellow and it's clearly a different plastic to the STs, which also vary wildly in their yellowing.

I guess it's down to storage conditions? my other C64C as posted before is a lovely new looking shade of beige and I've also got a couple of XE cases that look like new, in fact Im not sure I've ever seen an XE case yellowed. So as you say, probably down to the different plastics used?

Doh, make that 4 C64s that I own. The number of retro computers I own is meant to be decreasing not increasing.

PhilC wrote: 10 Nov 2021 10:53

rubber_jonnie wrote: 10 Nov 2021 10:47
The differences between machines is quite surprising to me, I have a similar C64 and it's definitely paler and less yellowed than yours. Similarly, I have an Atari 65XE that is as fresh as the day I bought it, yet I have seen others that are super yellow and it's clearly a different plastic to the STs, which also vary wildly in their yellowing.

I guess it's down to storage conditions? my other C64C as posted before is a lovely new looking shade of beige and I've also got a couple of XE cases that look like new, in fact Im not sure I've ever seen an XE case yellowed. So as you say, probably down to the different plastics used?

Possibly, this is a conversation I think has popped up on here a few times. I have a Dreamcast which was always stored inside, and not exposed to direct sunlight, but it has still yellowed. Inside it's still the original colour, even where the PSU is and it's extra warm. I have a SNES that has gone yellow despite being stored in a box, so that's another one I can't figure. I can only surmise it's due to the original plastics ingredients.

I think maybe Sinclair got it right by going with black!

PhilC wrote: 10 Nov 2021 11:03 Doh, make that 4 C64s that I own. The number of retro computers I own is meant to be decreasing not increasing.

It's ok, I have over 50 machines including about 15 STs of various types. It's normal, you'll be fine.

Yeah, Ive got like 5 C-64 'type' machines knocking around the house in a cupboard or other storage, so don't sweat it! :D

('Type' machines: regular breadbin, 3xC64DTVs and a C128D).

Edit:

Anyway, heres a highly recommended c64 synth: https://csdb.dk/release/?id=207214

Also, its still in alpha, but heres a SID mixer: https://csdb.dk/release/?id=201357

That mixer alone must be a good reason to own more than 1 c64 right? :D

rubber_jonnie wrote: 10 Nov 2021 11:05

PhilC wrote: 10 Nov 2021 10:53

I guess it's down to storage conditions? my other C64C as posted before is a lovely new looking shade of beige and I've also got a couple of XE cases that look like new, in fact Im not sure I've ever seen an XE case yellowed. So as you say, probably down to the different plastics used?

Possibly, this is a conversation I think has popped up on here a few times. I have a Dreamcast which was always stored inside, and not exposed to direct sunlight, but it has still yellowed. Inside it's still the original colour, even where the PSU is and it's extra warm. I have a SNES that has gone yellow despite being stored in a box, so that's another one I can't figure. I can only surmise it's due to the original plastics ingredients.

I think maybe Sinclair got it right by going with black!

Fluorescent lights also produce UV.

I have a "Portal 2" turret which has been in my office for about 5 years and it's yellowing in the direction of the lights and not the window.

Also, once the plastic has been exposed then it can develop later in the dark. Some plastics will bleach back to white if brought back out into the light. It very much depends upon the chemistry of the additives.

stephen_usher wrote: 10 Nov 2021 12:56
Fluorescent lights also produce UV.

I have a "Portal 2" turret which has been in my office for about 5 years and it's yellowing in the direction of the lights and not the window.

Also, once the plastic has been exposed then it can develop later in the dark. Some plastics will bleach back to white if brought back out into the light. It very much depends upon the chemistry of the additives.

My Dreamcast was new, and I don't have any fluorescent lighting, though I suppose it may have been exposed in the factory and then exposed later as you suggest.

I think it's a much more complex scenario though, with a lot more factors involved.

rubber_jonnie wrote: 10 Nov 2021 13:13 I think it's a much more complex scenario though, with a lot more factors involved.

Cosmic radiation?! :shock:

rubber_jonnie wrote: 10 Nov 2021 13:13 My Dreamcast was new, and I don't have any fluorescent lighting, though I suppose it may have been exposed in the factory and then exposed later as you suggest.

I think it's a much more complex scenario though, with a lot more factors involved.

My Dreamcast is exactly the same. It looks worse than most of the youtube before and after ones, yet I have treated the thing with kid gloves as they say.

As I understand it the yellowing is caused by bromides in the plastic - used to make it more fire retardant IIRC - and I remember a bromine test at school (far too many years ago!) which showed it as quite an "active" chemical. So I guess it is coming out of the plastic, and not being "burnt off" by sunlight/UV as well as being more mobile when in sunlight. So lose-lose both ways. Leave it in sunlight and it speeds up the action of yellowing, but it will happen anyway through time. My list of items that need "retro-briting" is now longer than we have sunny days for!