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How to remove yellowing from an old Atari case

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On 8/12/2020 at 7:28 AM, Mclaneinc said:

Sadly after all the prep I was put off retrobrighting but its my own fault. Now you would think a huge plastic box covered in foil and UV led's popping out everywhere would be hard to miss but I put a C64 breadbin top half in and forgot about it despite it being under my feet (almost). When I took it out I was saddened to see that where the pillars the screws going into inside the top half were showing white circles on the outside of the case. So whereever the screws go into the top half there were light circles showing the size of the pillar inside...Bloody weird and very annoying.

 

So I did the bottom half and took much more care (ie didn't forget about it) and it came out ok but the top and bottom don't exactly match (top is lighter), its minor but you can see it close up..

 

I'm still going to do my USA Snes as its can't look any worse and fingers crossed it will be fine..

I'm just catching up on your progress Paul as I've not been online for a few days with this heatwave. Sorry to hear that you had a mishap with the liquid, how long did you leave the case top in? I've been in two minds about whether to risk my breadbin case so I'm certainly put off now, I'm not sure that mine is discoloured at all as the beige is the same inside and out. There's too many variants of the case to judge the shade of the plastic from memory although I do remember my one from the mid eighties being pretty much the same colour. I'm not too worried about the Amiga cases and the light XL case sections, as I feel they will fair well in the liquid. The lower quality XE cases are another concern though.

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Hi Tezz, my top lid was 18hrs, as said I forgot about it..Well I checked it initially and then lost track of time...

 

The bottom was fine and certainly looks more right than the dark brown its had become..

 

My next test in the USA SNES the bottom is completely the wrong colour, it should be a bluey grey but its beige, looking online it seems to be a common issue..It looks wrong so I can't possibly make it worse (hopefully) and its a test to see if I continue with the treatment on other cases..

 

I'm pretty sure it was just my silly mistake on the C64 top..From all the reading its the most safe way to avoid streaking etc..Just keep a regular eye on it :) 

 

Also my tub got pretty warm which I know accelerates the retrobrighting, wasn't too hot but warm enough..

Edited by Mclaneinc

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On 8/12/2020 at 7:28 AM, Mclaneinc said:

Really nice Thomas, looks like it went swimmingly...

 

What is the hack on the last pic?

 

Is it the changing the impedance on the KB one?

 

Sadly after all the prep I was put off retrobrighting but its my own fault. Now you would think a huge plastic box covered in foil and UV led's popping out everywhere would be hard to miss but I put a C64 breadbin top half in and forgot about it despite it being under my feet (almost). When I took it out I was saddened to see that where the pillars the screws going into inside the top half were showing white circles on the outside of the case. So whereever the screws go into the top half there were light circles showing the size of the pillar inside...Bloody weird and very annoying.

 

So I did the bottom half and took much more care (ie didn't forget about it) and it came out ok but the top and bottom don't exactly match (top is lighter), its minor but you can see it close up..

 

I'm still going to do my USA Snes as its can't look any worse and fingers crossed it will be fine..

Thanks, really happy with it. I even managed to keep the stickers on the underside of the cases intact. Though the aluminium model badges could do with some love.

 

That bodge was done before I got the system (which I'm guessing was 1988?), so I assume it's factory or my uncles attempt to improve the display output as it's attached to the RF modulator. I'm sure more knowledgeable people on here can let us know.

 

I've a bunch of parts coming from from the UK and Poland to upgrade the internals and finish it off.

 

Really sorry to hear about that mishap!

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30 minutes ago, flemingt said:

I've a bunch of parts coming from from the UK and Poland to upgrade the internals and finish it off.

 

Really sorry to hear about that mishap!

 

These things happen and it's totally my own silly fault...

 

More mod's, an Ultimate 1MB?  (Totally recommended and get the Flashjazzcat version of the bios, can be flashed on later though)

 

Whatever the mods are, you have fun there Thomas..

Edited by Mclaneinc

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yes, U1MB ordered, along with a proper AV cable. Also, some cheap and cheerful ram chips from ebay to get it up to 64kb too.

 

I will try, a lot to learn (and re-learn!).

 

hopefully you have better luck on your next retro-brightening attempt. 

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On 8/13/2020 at 12:16 PM, Mclaneinc said:

 

These things happen and it's totally my own silly fault...

 

More mod's, an Ultimate 1MB?  (Totally recommended and get the Flashjazzcat version of the bios, can be flashed on later though)

 

Whatever the mods are, you have fun there Thomas..

 

I retrobrighted a Commodore 1702 monitor, and it showed some irregularities until I wiped the whole case liberally with baby oil.  The lanolin in the baby oil might really help your top (and bottom) case.  

 

It's cheap and easy; give it a try - I think you'll be pleased.

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For me - peroxide in clear liquid form (diluted with water if it's really "strong") and UV light. Submerge the case in the solution, add 2x50W UV lights and 2 hours later the yellowing is gone. If it's really bad - 3-4 hours later. If it's _really_ bad (see fjc's "Italian 1200XL ;)) - spray paint (never did that but @flashjazzcat got excellent results with the 1200XL).

I don't like peroxide in cream form - I'm a bit afraid of "streaking" etc... clear liquid works for me.

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18 minutes ago, damanloox said:

If it's _really_ bad (see fjc's "Italian 1200XL ;)) - spray paint (never did that but @flashjazzcat got excellent results with the 1200XL).

Yes - it turned out well, especially given that it's about eight years since I did any spray-painting:

IMG_20210517_101459421.thumb.jpg.5e44c8ed763890e82c214380571be535.jpgIMG_20210517_101448416.thumb.jpg.931ee700238e5f16777574b44c01d7fc.jpgIMG_20210517_101438680.thumb.jpg.246871e9ad9fe8740c7924057b13c0fc.jpgIMG_20210517_101434285.thumb.jpg.8b101eedbd768ab3da62b18482bf4e8a.jpg

 

20 minutes ago, damanloox said:

I don't like peroxide in cream form - I'm a bit afraid of "streaking" etc... clear liquid works for me.

Yes: I hear of and see good results with fully submerged parts. Will have to try this when the opportunity arises.

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6 minutes ago, flashjazzcat said:

Yes: I hear of and see good results with fully submerged parts. Will have to try this when the opportunity arises.

I use "transparent" container which I then wrap (on the outside) with aluminium foil (in hope that some of the UV light will be reflected onto hard to reach parts). Not sure if it really helps but it seems to work for me.

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5 minutes ago, damanloox said:

I use "transparent" container which I then wrap (on the outside) with aluminium foil (in hope that some of the UV light will be reflected onto hard to reach parts). Not sure if it really helps but it seems to work for me.

Internally reflective surfaces really help, I think. My 'magic light box' wasn't very effective until I lined the inside with aluminium foil. With the foil, it's arguably as effective as sunlight.

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I wasn't sure if the aluminium foil reacts with peroxide so I thought outside was "safer" (taking risk at my age is.. risky ;))

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1 hour ago, damanloox said:

I wasn't sure if the aluminium foil reacts with peroxide so I thought outside was "safer" (taking risk at my age is.. risky ;))

Oh - I would have done the same, even if to ensure the foil doesn't 'float off'. I was applying it to the inside of a cardboard box. :)

 

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If you use foil inside the container with the peroxide liquid its spoils the foil..Well it did when I tried it, could have just been that it was really cheap foil..Ideal would be a fish tank with real mirrors on all sides..

 

I've tried both liquid and the cream methods, neither worked great for me, the liquid did work better with more heat applied..

 

Must try it again sometime, I've got an Amiga 500 that is just begging to be the right colour again..

 

@damanloox which country did you do the sunlight way, must have been Poland as Ireland is usually the land of the grey skies and moisture... (I'm originally from Northern Ireland)

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12 minutes ago, Mclaneinc said:

If you use foil inside the container with the peroxide liquid its spoils the foil..Well it did when I tried it, could have just been that it was really cheap foil..Ideal would be a fish tank with real mirrors on all sides..

 

I've tried both liquid and the cream methods, neither worked great for me, the liquid did work better with more heat applied..

 

Must try it again sometime, I've got an Amiga 500 that is just begging to be the right colour again..

 

@damanloox which country did you do the sunlight way, must have been Poland as Ireland is usually the land of the grey skies and moisture... (I'm originally from Northern Ireland)

Peroxide cream & cling film in IE on a summer's day, it worked a treat.

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Posted (edited)

@Mclaneinc I'm using 50 W UV lights as substitute for the Sun ;) 

 

As for ideal container - yes - fish tank with mirrors on the sides would be ideal. But I don't have one and plastic container with tin foil worked very well for me (on several occasions - including XLs, XEs, STs and SNES). 

Edited by damanloox

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Light brightening party!  The fan keeps them much cooler. The dark keyboards get hot otherwise. Humidity is about %19 which is probably great for brightening.

 

Atari-light-brighting-June-2021.thumb.jpg.f2877198e3d0473447758e15ca1096c3.jpg

 

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A word of warning about leaving 65XE's and 130XE's out in the sun. It seems the sun is bleaching the color out of the entire badge, including the grey, but most noticeably the red ATARI is now faded.  Maybe it's just age and not the sun but not willing to test this theory on another machine. Covering the badge may be advised to avoid this! Two machines shown, XE on right has never been out in the sun or retro brighted.

sun-brightening-fading-XE-badge.thumb.jpg.a43f0b81e47cfa9a5a080ae31c7e6a49.jpg

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