A Retrobrite and Plastikote Experiment (Amiga 4000)

As requested here's a 6 month update photo. No significant yellowing yet but I definitely think it has slightly returned, it looks better in natural light like this than it does in artificial light. As a reminder the 2nd FDD drive cover is the piece treated with plastikote, and the FDD drive was not retro-brighted so is still quite yellow. The power button is naturally still white and has never been retro-brighted.
 

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well, i can see that it has darkened a bit ....
But i would say tests are inconclusive.
I wonder if you can retr0bright that part again, since it's coated in laquer
 
After all these months, are the parts treated with the Plastikote lacquer whiter than the rest or is the yellowing the same overall ?
 
After all these months, are the parts treated with the Plastikote lacquer whiter than the rest or is the yellowing the same overall ?

I don't think that sealing the plastic makes any difference at all, they have both started to yellow again at the same rate.
 
I'm doing some tests myself, did you completely sprayed the part all around or just where it was yellow?
 
I wonder if there's a process like anodising but for plastics. Soak it in a chemical to etch the surface and open up micro pours, retrobright it, then soak in hot water for a period of time to close the pours?
 
The A4000 is quite odd for a Commodore machine in that its white and has no printed logo which means it lends itself to painting really well. I have two, one of which I had the front fascia and floppy cover colour matched and painted professionally last year and it looks indistinguishable from its unpainted brother... except that one of them will never go yellow again :D

The beige beauties are a different beast but for me, with the A4000 mask the badge and paint it :D
 
Aysel, what is the actual colour? I always remember A4000's as being a very pale ivory-grey kind of colour.
 
I'd start worrying if I was you, the ST I did 2 years ago is turning and olive shade of green :LOL: Still, looks better than the brown it originally was :LOL:
 
Aysel, what is the actual colour? I always remember A4000's as being a very pale ivory-grey kind of colour.

Im not sure mate... I have a keyboard which is completely origional, never yellowed and my friend who works at a bodyshop just used a gadget he has to read the colour, this gave him a code and he ordered the paint mixed to that spec, he used a plastic primer, painted then a really nice matt lacquer you honestly cant tell its painted and will last forever.
 
As promised, here's the results a year after retrobrighting. To recap, I treated the main fascia and the lower drive cover, but covered the drive cover in Plastikote to cut off the oxygen. Well, see for yourself:

plastikote1.jpgplastikote2.jpg

Compared to the non-yellow 'control piece' on the left, they have both yellowed again at exactly the same rate. Only now, I can't retrobright the driver cover again as it's sealed :)

So my advice based on experience is ignore this below thread, it's simply not true:

https://www.amibay.com/showthread.p...s-own-is-not-a-permanent-solution-here-s-why/
 
Either your white balance is off or I'm blind but I can't see any yellowing in the pictures :)
 
This shows the difference better, compare to my keyboard and especially keys.
 

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So it is just to forget this method on my yellow 4000
But when I think that I go for painting in a matt white color, it is 100 times better than a yellow amiga if you ask me.


can be the plastic react to coloring too
someone who has a 3D printer? :)
hm
 
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someone who has a 3D printer? :)

That's the way forward, manufacture new fascias. The problem is it's not cost effective. They're too big to 3D print, and making injection moulds costs a fortune, as per the recent A1200 case campaign. I think you could probably sell 50-100 A4000 fascias at say £50 each, but that's only £5000. It would cost far more than that to make them. Hopefully one day 3D printers improve in both quality and size.
 
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