Got my ZX80's guts running today. But the enclosure looks horrible... Looks like it had a beating with a soldering iron and it is quite yellow. I have already removed most of the melted spots with 1500 grit sandpaper, but I want to use RetrObright to bring it back to a pristine condition.
Has someone tried to whiten his ZX80 with Retrobright? I found one article where bits of the ZX80 logo chipped off after a RetrObright treatment.
Anyone any experience? I've got 12% hydrogen-peroxide coming my way and it will be quite sunny here over the weekend, so I might give it a try anyway. Can't get any worse than it is now...
First make a Mask with some Paper towels (Toilet-Paper works as well).
Put the paper on the plastic and take a sponge with water. Dab the paper carefully. If the paper is damp and all white surfaces are covered, let it dry.
Then you take the sponge and dab the paper with the hydrogen-peroxide (I used 35%) ... after about a day it should already be beautifully white!
If you want to do that with a keyboard, just take hydrogen-peroxide and put the keys in it...
zx81jens wrote: ↑Wed May 24, 2017 10:46 pm
Yes, I did that with a TRS-80-Compatible (Videogenie I)...
That´s how it works good:
First make a Mask with some Paper towels (Toilet-Paper works as well).
Put the paper on the plastic and take a sponge with water. Dab the paper carefully. If the paper is damp and all white surfaces are covered, let it dry.
Then you take the sponge and dab the paper with the hydrogen-peroxide (I used 35%) ... after about a day it should already be beautifully white!
If you want to do that with a keyboard, just take hydrogen-peroxide and put the keys in it...
Greetings
Jens
Hi Jens,
Fantastic picture Great results indeed! And thanks for the info. I will definitively give it a go over the weekend.
I'm only getting 12% strength btw. Did you also use Vanish Oxy Action (or similar) as a catalyst? Or just the 35% peroxide?
I found so many variations on the 'recipe'. Also with Xanthan gum to turn it into a gel.
Some say you have to leave it outside on a sunny day. Others claim only UVA lamps will do the job. And some say leaving it (enclosed) in your living room is enough. Did you leave you TRS-80 indoors or outdoors?
I've done quite a lot of retr0brighting over the years with various systems and it is unfortunately not a permanent solution. Like many others in the early days I assumed that protecting the treated surfaces with UV sealers after the process would prevent it from occuring again. The problem is that the yellowing effect caused to the plastic (which includes a fire retardant bromide) from its exposure over the years actually creates degraded free bromides throughout the plastic, the Retr0brighting process only removes these away from the surface layer. The bromides will continue to move through the polymer again regardless of light exposure and furthermore the re-yellowing is accelerated with heat, in any case sadly the bromide will eventually migrate to the surface again within a few years or sometimes sooner depending on the extent of the yellowing. I did read an article a while ago which suggested that it was the plastics exposure to oxygen that caused the bromide to return to the surface and completely sealing it could be the key but I suppose any solution in that respect would be demonstrated by now if that was the case. I've considered plastic dyes which bond to the surface but they are banned in the UK.
Tezz wrote: ↑Thu May 25, 2017 12:16 am
I've done quite a lot of retr0brighting over the years with various systems and it is unfortunately not a permanent solution. Like many others in the early days I assumed that protecting the treated surfaces with UV sealers after the process would prevent it from occuring again. The problem is that the yellowing effect caused to the plastic (which includes a fire retardant bromide) from its exposure over the years actually creates degraded free bromides throughout the plastic, the Retr0brighting process only removes these away from the surface layer. The bromides will continue to move through the polymer again regardless of light exposure and furthermore the re-yellowing is accelerated with heat, in any case sadly the bromide will eventually migrate to the surface again within a few years or sometimes sooner depending on the extent of the yellowing. I did read an article a while ago which suggested that it was the plastics exposure to oxygen that caused the bromide to return to the surface and completely sealing it could be the key but I suppose any solution in that respect would be demonstrated by now if that was the case. I've considered plastic dyes which bond to the surface but they are banned in the UK.
Hmmm... Thanks for the info! I'm going to give it a try anyway. Can't get any worse than it is now I can always Rebright it again. I'll do some more research. Hydrogen peroxide should arrive tomorrow...
A chemist and her friend walked into a bar. The waiter appeared and asked what they would like to drink. The chemist, being funny, said "I'll have a glass of H2O please". Her friend, laughing along, said "And I'll have a glass of H2O too!" He died.
sirmorris wrote: ↑Fri May 26, 2017 12:57 pm
A chemist and her friend walked into a bar. The waiter appeared and asked what they would like to drink. The chemist, being funny, said "I'll have a glass of H2O please". Her friend, laughing along, said "And I'll have a glass of H2O too!" He died.
I wonder what kind of bar in the UK will have H2O2. Must be full license?
In theory, there is no difference between theory and practice. But, in practice, there is.
Great results indeed! And thanks for the info. I will definitively give it a go over the weekend.
