Removing yellowing from old computer cases, solved!!

Moderators: Mug UK, Zorro 2, Greenious, Moderator Team

User avatar
Merlin
Atariator
Atariator
Posts: 22
Joined: Thu Apr 24, 2008 4:16 pm
Location: Mancland, UK
Contact:

Re: Removing yellowing from old computer cases, solved!!

Postby Merlin » Mon Feb 16, 2009 10:04 pm

Just to show how much of an anorak I have become about this topic....

Have you ever seen black bumpers (fenders) on cars, that gradually turn grey then white under sunlight? Well, that's because the bumpers are made of...yes, you've guessed it.... ABS.

The years of direct UV light gradually degrade any free double bonds from the butadiene parts of the ABS down to the hydroperoxide and the manufacturer's don't put enough carbon black pigment into the material to mask this.

The only ways I know to fix that are either black liquid shoe polish or matt black paint; the whitening is irreversible as far as I know, unless someone wants to prove me wrong.....

User avatar
jkolak
Atari maniac
Atari maniac
Posts: 87
Joined: Mon Sep 08, 2008 4:51 am

Re: Removing yellowing from old computer cases, solved!!

Postby jkolak » Wed Feb 18, 2009 1:56 am

Desty wrote:Wow, that's a massive difference. The right side looks like an oompaloompa. If I treat mine, I'll definitely take some before and after pics, but I don't think they have very pronounced yellowing (the old mono monitor is yellower than Homer Simpson's arse, but I'm not sure exactly how to take it apart safely :D).


Oh, that's easy. The main thing is to respect the potentially fatal voltage stored by the CRT. Once you pull the back off, you will find the CRT secured to the face plate with screws in the four corners. Just remove them to release the face from the CRT. Just the usual care in watching for how the knobs, circuit board, and wires interface with the assembly and you've got it.

User avatar
jkolak
Atari maniac
Atari maniac
Posts: 87
Joined: Mon Sep 08, 2008 4:51 am

Re: Removing yellowing from old computer cases, solved!!

Postby jkolak » Wed Feb 18, 2009 1:58 am

Merlin wrote:The only ways I know to fix that are either black liquid shoe polish or matt black paint; the whitening is irreversible as far as I know, unless someone wants to prove me wrong.....


Your neighborhood FLAPS should have some products for sale to address this issue. One product called Back to Black comes to mind.

(Friendly Local Auto Parts Store)

mimo
Atariator
Atariator
Posts: 27
Joined: Mon Apr 23, 2007 10:49 pm

Re: Removing yellowing from old computer cases, solved!!

Postby mimo » Sat Mar 07, 2009 11:27 pm

Just done a 520STe, worked out pretty well :D Image

Nicely yellow on the left
Image
Spanking new :D
Image

Image

Shredder11
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 2434
Joined: Mon Nov 26, 2007 2:23 pm
Location: West Yorkshire, United Kingdom (England)
Contact:

Re: Removing yellowing from old computer cases, solved!!

Postby Shredder11 » Sun Mar 08, 2009 11:07 am

Call me a big over emotional softy but I think that STe looks fit for a king......really beautiful now! :cheers: :o

User avatar
jkolak
Atari maniac
Atari maniac
Posts: 87
Joined: Mon Sep 08, 2008 4:51 am

Re: Removing yellowing from old computer cases, solved!!

Postby jkolak » Sun Mar 08, 2009 11:36 am

Shredder11 wrote:Call me a big over emotional softy but I think that STe looks fit for a king......really beautiful now! :cheers: :o


Hear Hear!!

Shredder11
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 2434
Joined: Mon Nov 26, 2007 2:23 pm
Location: West Yorkshire, United Kingdom (England)
Contact:

Re: Removing yellowing from old computer cases, solved!!

Postby Shredder11 » Sun Mar 08, 2009 12:18 pm

I wonder if we shall see a medieval wizard named in the next New Years Honours List?........... :wink:


.....for let it be known that no finer contribution for thy Queen, shall ever be blessed unto thy kingdom! :megaphone: :cheers: :mrgreen: 8)

User avatar
rocket-dog
Atari Super Hero
Atari Super Hero
Posts: 779
Joined: Wed Mar 05, 2008 3:13 pm
Location: Great Britain - The Kingdom of Mercia

Re: Removing yellowing from old computer cases, solved!!

Postby rocket-dog » Sun Mar 08, 2009 12:27 pm

Shredder11 wrote:Call me a big over emotional softy but I think that STe looks fit for a king......really beautiful now! :cheers: :o


Shredder, you are a big over emotional softy. :mrgreen:

It seems the news of this technique is spreading. It was mentioned on this week's RetroMac pod cast.

http://retr0bright.wikispaces.com/

mimo
Atariator
Atariator
Posts: 27
Joined: Mon Apr 23, 2007 10:49 pm

Re: Removing yellowing from old computer cases, solved!!

Postby mimo » Sun Mar 08, 2009 11:03 pm

Shredder11 wrote:Call me a big over emotional softy but I think that STe looks fit for a king......really beautiful now! :cheers: :o

Thanks, that makes me feel all warm inside :D
Seriously I am chuffed that it came out so well and my ST is good for another 20 years (fingers crossed)
It is really simple to do this, just a bit time consuming to do all the keys.
This one was a bit stubborn as I have mentioned elsewhere, total time was about 12 hours in the sun.
Used 200ml Hydrogen Peroxide, 2 tsp Xanthan gum, 1/4 tsp T.A.E.D. Total cost to do this one was about £1 :mrgreen:

Go on, treat your ST to a make over :cheers:
Image

Image

flashjazzcat
Atari User
Atari User
Posts: 38
Joined: Fri Mar 06, 2009 9:42 am

Re: Removing yellowing from old computer cases, solved!!

Postby flashjazzcat » Sun Mar 29, 2009 4:28 pm

These ST's can be stubborn; mine's in the garden now, making the most of the last of the sun. The keyboard's done, and the case is just about done apart from a green strip along the bottom front edge. I suspect that because of this area, I won't be able to reassemble the thing tonight. Still - the keyboard's almost like new:

keyboard2.jpg
You do not have the required permissions to view the files attached to this post.

flashjazzcat
Atari User
Atari User
Posts: 38
Joined: Fri Mar 06, 2009 9:42 am

Re: Removing yellowing from old computer cases, solved!!

Postby flashjazzcat » Sun Mar 29, 2009 8:02 pm

Looks like what I assumed to be the base colour coming through was actually blooming. The bottom of the case looks great, but the top's a real mess:

Atari.jpg


Short of painting the case I think I'll be on the hunt for another case or an STE. :cry:
You do not have the required permissions to view the files attached to this post.

simbo

Re: Removing yellowing from old computer cases, solved!!

Postby simbo » Mon Mar 30, 2009 3:07 am

well give it a cook in the glorious summer all day all night at the window for a few months
it will be back to yellow
but this time maybe a better oxidised iodine colour
st cases are rf photonic sensitive
you could freeze dry them lock them in so thick a lead super super man cant see them
and they will still go yellow
becouse the molicule the mold slip {molding fire retardant} is made from
is non stable and is infused with there plastics at a molecular level
in invarient levels
and due to RF and OPTICAL radiation it hyperoxidises goes to black
sometimes to i would say .1mm or more
all your leaving when you bleach it is a new layer that will now age super fast!!!
and brittle plastics result becouse of case cohession errosion...
becouse the surface molicule is stripped of its chain parts so it will
de-stabilise leading to a cascade effect (time/melting plastic) to brittle plastic branches of what was molicule trees
much like teath do if you irrigate them too much with bleach to clean away
bacteria ask a denstist what happens to over hyperoxidised calcium ...

no amount of bleeching {hyperoxidising }them will fix this cluck up
try this
bleech a mouse this way
then age it
simply place it in a microwave for 20 seconds each time you cook for a month so 2 X 20 second blasts a day
this i think would represent 15 years in even just RF around us
then compare it to white
youll see its mustard
so...... i rest my case ... and maybe others have
trick is to look over older posts from 2003 or so or well before about this issue
then decide what to do
however properly done youll get 5-10 years much like a marrage these days....
best get the paint ready!!!! again!
painting first with something that yields electons to stabalise the case
i know iron oxide paint primer good old cure i think so...!!!!
it makes a dam good rf screen so you can afford to loose the top metal screening
making space for satandisks etc
many reasons to paint and not bleach
dont say i told you so
in five year time your problems will be MUCH worse !!! beleve me
if you love your atari the way it is
a bit old and yellowed then first paint with latex rubber then with latex paints
at least it forms when sealed with a fixer spray a uniform dynamic coating
you can always add to
and anyway peal off if you no longer like the colours
bleech no rubber yes ...
bleech protect's nothing ....!!!
your atari case maybe 99% deadf you do!

as for the keyboard maybe a pillow case for washing and a pair of tights for removing keys as alison says is aok
you can use a simple wet cloth and some detergant to remove crap from the keyboard lower half ive never seen a yellow one that isnt easily cleaned without stripping it all appart to the plastics
youll notice the keys dont actualy get yellow thats just ingraned dirt
any bio wash soap will remove on 30deg cycle

all that bleach actual does is oxidise metals in the molicule then it breaks up and stops resonating and falls to bits
as a particular light wavelenght element{as well as many other resonant points in RF the spectrum like ghz zone}
so the case will moslty adopt uniform valux refraction and looks white
but goes yellow now much faster

the st esp stf and fm and rev a b ste rev1 falcon some megas
surface molicules are so unstable when bleached
a larger than normal curry fart would make them turn safron for sure...!!!

other than turning into a morloc and risking living in a vacume sealed fariday cage
i see no other solution than to paint or plate.... them
funnily enought the best ataris live further from the sea i notice....

salts play a big part in rf and electromagnetic/photonic plastics depletion time scale

....

you know once i had a brand new ste
the first thing i pulled out was a leaflet that warned never to clean the atari case with anything other than water
and 'mild detergant'

simbo

Re: old for new back to chrome

Postby simbo » Mon Mar 30, 2009 4:12 am

in my local area is a place that can 'plate' plastic

you give them the case for your few st etc machines
{i think it will cost me a case of beer and 20 quid if i play my cards right}

they will dip it in some sort of acid to clean it then flash plate it will a sub metal
then clean again and plate a top metal of your choice

even 24crt gold
it will cost i assume a little extra

but its worth it
as it will NEVER errode for sure!!!! and 100% RF screens
and it will
1: always be yellow sf them
2: outlive them and you

this process can be done at home
you need
nitric acid {1mole}
aluminium nitrate salts
gold nitrate salts
a grinder to discant the salts
and a large flash pan and probes
150v dc 2 amp supply {HWR 240 is fine}
flame cupboard
large treated chemo safe rubber gauntlets {advised for peroxides also}

flashjazzcat
Atari User
Atari User
Posts: 38
Joined: Fri Mar 06, 2009 9:42 am

Re: Removing yellowing from old computer cases, solved!!

Postby flashjazzcat » Mon Mar 30, 2009 7:35 am

Well, the solution was to gently rub the surface with little nail-polish remover on a cloth. All the blooming's come off, and although the surface texture has changed, by dabbing the surface it's possible to achieve an even, slightly more matte finish than the original. Quite acceptable, and I'll do the finishing touches tonight and post some comparison photos. It should look pretty good, especially when the badge is replaced. :)

flashjazzcat
Atari User
Atari User
Posts: 38
Joined: Fri Mar 06, 2009 9:42 am

Re: Removing yellowing from old computer cases, solved!!

Postby flashjazzcat » Mon Mar 30, 2009 6:06 pm

Finishing off with a magic eraser and it looks pretty good now:

520STFM.jpg
You do not have the required permissions to view the files attached to this post.

User avatar
jkolak
Atari maniac
Atari maniac
Posts: 87
Joined: Mon Sep 08, 2008 4:51 am

Re: Removing yellowing from old computer cases, solved!!

Postby jkolak » Tue Mar 31, 2009 5:00 am

flashjazzcat wrote:Well, the solution was to gently rub the surface with little nail-polish remover on a cloth. All the blooming's come off, and although the surface texture has changed, by dabbing the surface it's possible to achieve an even, slightly more matte finish than the original. Quite acceptable, and I'll do the finishing touches tonight and post some comparison photos. It should look pretty good, especially when the badge is replaced. :)


I hate to see resorting to acetone. Surely some milder could have removed the blooming.

flashjazzcat
Atari User
Atari User
Posts: 38
Joined: Fri Mar 06, 2009 9:42 am

Re: Removing yellowing from old computer cases, solved!!

Postby flashjazzcat » Tue Mar 31, 2009 6:20 pm

jkolak wrote:I hate to see resorting to acetone. Surely some milder could have removed the blooming.


I don't know. I tried a number of things without success first but the blooming was really bad. The blooming, as I understand it, is the very top surface of the plastic, attacked by the peroxide and stripped of its pigmentation. The only way to remove it must be to remove that layer of uppermost particles. Perhaps I could have worn out ten magic erasers and done it that way. :) For finishing, they're great: you can work up a nice satin texture similar to the original. I also used acetone on the green discolouration along the front of the bottom of the case, since it was so severe and had barely responded at all to eight hours' peroxide treatment. I'm sure everyone's application of the Retr0Brite treatment differs; some will do it better than others, and I'm sure one batch of plastic will respond differently to the rest. We're at the forefront of experimentation, really, with this restoration technique and without doubt I made mistakes and have learned from them. The upshot is that the ST now looks considerably better than it did when I acquired it and vastly better than it did before the blooming was removed. As damage limitation goes, it's been successful. :)

User avatar
Desty
Atari God
Atari God
Posts: 1951
Joined: Thu Apr 01, 2004 2:36 pm
Location: 53 21N 6 18W
Contact:

Re: Removing yellowing from old computer cases, solved!!

Postby Desty » Wed Apr 01, 2009 12:52 am

jkolak wrote:I hate to see resorting to acetone. Surely some milder could have removed the blooming.

flashjazzcat wrote:As damage limitation goes, it's been successful. :)

Acetone is a very risky thing to use indeed; I used a drop of nail polish remover on one of the keys on an STE and within a couple of seconds it had melted the plastic slightly, so the end result is a) permanent and b) worse than the stain it removed :|

Glad it worked out for you in this case though - the picture suggests that you did an excellent job!
tá'n poc ar buile!

flashjazzcat
Atari User
Atari User
Posts: 38
Joined: Fri Mar 06, 2009 9:42 am

Re: Removing yellowing from old computer cases, solved!!

Postby flashjazzcat » Wed Apr 01, 2009 5:30 pm

Desty wrote:Acetone is a very risky thing to use indeed; I used a drop of nail polish remover on one of the keys on an STE and within a couple of seconds it had melted the plastic slightly, so the end result is a) permanent and b) worse than the stain it removed :|

Glad it worked out for you in this case though - the picture suggests that you did an excellent job!

Thanks. I tried acetone on a couple of XE keys, months before the Retr0Brite technique was discovered, and it faded the lettering. One need hardly be surprised that that happened, and since the case was barely discoloured at all, I elected to purchase a new keyboard from Best Electric and the 8-bit looks good as new. Doubtless the original keyboard could have been restored to shop condition had I known then about the peroxide treatment, and this was indeed the case with the ST's keyboard. The lighter plastic of the keys is less prone to visible blooming, but clearly care should be exercised when using any chemical on plastic - corrosive or otherwise. While I appreciate that appliance manufacturers in the 1980s would have urged owners to use nothing more than a damp cloth when cleaning plastic surfaces, I also doubt they realized that the fire-retardant chemicals in the material would turn the appliances brown in the space of twenty years. The peroxide treatment is a great innovation, and far from being frightened off by a near disaster, I now feel better informed for the next project. I would urge people thinking of trying Retr0Brite on valued computers to proceed, but proceed with care. Don't put too much OXY in the mixture, rinse and check surfaces regularly, and ideally keep them covered (perhaps with polythene) if outdoors to prevent the drying out of the mixture that can result in the peroxide becoming too concentrated and attacking the plastic. It's far from being a doddle, and a long way from being something you could buy off the shelf with any kind of guarantee attached to it. People have had varying results with the procedure and it's impossible to know how effective it will be without extensive testing beforehand. In my case, two halves of the same computer came out completely differently. The ST's are known to be quite stubborn, but the bottom of the case was a breeze. If you see a quaintness about a discoloured computer or believe the yellowing is part of its character, you've saved yourself a whole lot of risky work by leaving it alone. But for the rest of us, the results can be extremely pleasing, and the sense of achievement considerable.

KLund1
Captain Atari
Captain Atari
Posts: 389
Joined: Fri Apr 03, 2009 5:09 pm

Re: Removing yellowing from old computer cases, solved!!

Postby KLund1 » Sun Apr 05, 2009 7:48 am

I've done this h2o2 process on a few 800xl's, 1050's and even my 1200xl. Works great!! But only on the cream colored parts. Did it once on the brown section and it messes it up some. With the gray of my STE case I'm still on the fence as to try this.
I saw earlier in this post an ST with the label popped of. Good. This process will pull the ink(?) off labels/decals. But how was it popped off? Mine looks glued in.
Also I used number 40 developer from a beauty supply store. It is already thick. You don't need to try and find and mix those other ingredients. And it costs very little. I got 1 16oz bottle for $3.75USD. Just add the OXY, mix, and paint on the case. Replay as it drys in the sun. UV black lights do not work nearly as well as the sun.
Any one else willing to test on an ST case, other than the one posted here?? I think we all need a bit more convincing.
UPDATED: Falcon 030(FX-1)(CF int & removable SD), MSTE 4+PS3000 4160STE 2.06+HDFD STacy4-internal-USD 1040STFM+I.B.Driver-5.25"FDD 1040STF 1040ST 520ST-AdSpeed 400-48k 800+810x2+820+822+825+830+835+850, 800XL+IndusGT 600XL 130XE+XF551x2 Portfolio 1200XL APE(Warp+32in1 OS SuperVideo 2.1 256k RAMBO)+1050x2 USD'd+SIO2PC, PC1+PCH204+PCM124+PCF554x2

flashjazzcat
Atari User
Atari User
Posts: 38
Joined: Fri Mar 06, 2009 9:42 am

Re: Removing yellowing from old computer cases, solved!!

Postby flashjazzcat » Sun Apr 05, 2009 1:39 pm

The label was brutally heaved off after I'd realized it had been ruined. They seem to be attached with some kind of adhesive film, a bit like double sided sticky tape, and it's actually very difficult to remove the badge without bending it. The replacement badge was still attached to fragments of the donor case and took some finessing to work loose. Personally, if I did another ST case, I'd just mask the badge.

I was somewhat grieved to notice I'd missed a 1040STE on ebay this morning which sold for £8 plus P&P about ten minutes before I switched the PC on. That would have been my next Retr0Brite project, since it looked pretty yellow. They are very difficult, these ST cases, and although I'm happy with mine now it's still not the original colour, I would say.

User avatar
Mug UK
Administrator
Administrator
Posts: 11209
Joined: Thu Apr 29, 2004 7:16 pm
Location: Stockport (UK)
Contact:

Re: Removing yellowing from old computer cases, solved!!

Postby Mug UK » Sun Apr 05, 2009 1:56 pm

The 'donor case' was trimmed as best as I could without breaking the badge in half :) Glad it's gone to a better home that sitting on top of a broken 520STFM with no lid :)
My main site: http://www.mug-uk.co.uk - slowly digging up the bits from my past (and re-working a few): Atari ST, Sega 8-bit (game hacks) and NDS (Music ripping guide).

I develop a free Word (for Windows) add-in that's available for Word 2007 upwards. It's a fix-it toolbox that will allow power Word users to fix document errors. You can find it at: http://www.mikestoolbox.co.uk

flashjazzcat
Atari User
Atari User
Posts: 38
Joined: Fri Mar 06, 2009 9:42 am

Re: Removing yellowing from old computer cases, solved!!

Postby flashjazzcat » Sun Apr 05, 2009 2:36 pm

Mug UK wrote:The 'donor case' was trimmed as best as I could without breaking the badge in half :) Glad it's gone to a better home that sitting on top of a broken 520STFM with no lid :)

You did a great job of trimming the case: it was actually easier to remove the badge from the fragmented plastic than it would have been were the case in one piece. :) I finally got around to removing the old adhesive from the back of the badge this afternoon, and I've just glued it in place properly. It looks great. Thanks again!

User avatar
Mug UK
Administrator
Administrator
Posts: 11209
Joined: Thu Apr 29, 2004 7:16 pm
Location: Stockport (UK)
Contact:

Re: Removing yellowing from old computer cases, solved!!

Postby Mug UK » Sun Apr 05, 2009 2:56 pm

No probs. Not sure what else I can use from this machine but I'll keep my eyes open on the "wanted" section and see where I can send the remaining donor parts to :)
My main site: http://www.mug-uk.co.uk - slowly digging up the bits from my past (and re-working a few): Atari ST, Sega 8-bit (game hacks) and NDS (Music ripping guide).

I develop a free Word (for Windows) add-in that's available for Word 2007 upwards. It's a fix-it toolbox that will allow power Word users to fix document errors. You can find it at: http://www.mikestoolbox.co.uk

KLund1
Captain Atari
Captain Atari
Posts: 389
Joined: Fri Apr 03, 2009 5:09 pm

Re: Removing yellowing from old computer cases, solved!!

Postby KLund1 » Fri Apr 10, 2009 9:02 pm

I'm not sure what would be a good 'mask' for the label. On one 800xl case, I used brown masking tape. and the paste went right through it. If we used something too strong, the sticky part could pull the color of the label off at the end of the process.
Any ideas what would be good enough to hold back the H2O2, and not pull the ink off later?
UPDATED: Falcon 030(FX-1)(CF int & removable SD), MSTE 4+PS3000 4160STE 2.06+HDFD STacy4-internal-USD 1040STFM+I.B.Driver-5.25"FDD 1040STF 1040ST 520ST-AdSpeed 400-48k 800+810x2+820+822+825+830+835+850, 800XL+IndusGT 600XL 130XE+XF551x2 Portfolio 1200XL APE(Warp+32in1 OS SuperVideo 2.1 256k RAMBO)+1050x2 USD'd+SIO2PC, PC1+PCH204+PCM124+PCF554x2


Social Media

     

Return to “Guides”

Who is online

Users browsing this forum: No registered users and 1 guest