How to remove yellowing from an old Atari case

[jowi]

Oh yeah i'm gonna take my time; will hang the lamp pretty high, gonna take it one hour at a time and check etc

[jowi]

Retrobrighting went perfect only needed 6 hours under the 400W UV Did the keys as well, the lettering was white in about 2 hours. This is no lightbulb, this is an artificial sun

Edited November 11, 2018 by jowi

[mimo]

looks good @jowi

[bfollowell]

For those of you that are more experienced with cleaning and/or retrobrighting older Atari cases, do you remove your serial number label from the bottom of the machine, or tape/cover it off in some way to protect it during the process?

 

If you have found a way to remove it for the process, what tricks to you use?

 

I want to protect mine during the process. Removing it much the way a philatelist removes stamps from an envelope, then reapplying it later would be ideal, but I'm not sure that's really feasible.

 

Thanks for any advice.

[Kyle22]

Nice, now hang the light over your Cannibis plants.

[jowi]

I don't think they will bloom under extreme ultraviolet

[AtariNerd]

So counterintuitive that is must have a certain truth:

 

https://youtu.be/8P1OVj0IcqY

[jowi]

So... the yellowing probably is caused by sunlight filtered through glass, and/or heat and ozone gas...?

I wonder if you can brighten using an UV light like in the 'old' method, but just leave out the peroxide... would be worth an experiment. Sadly i've got nothing to brighten at the moment...

[+DrVenkman]

So... the yellowing probably is caused by sunlight filtered through glass, and/or heat and ozone gas...?

 

Nicotine, too. Don't forget that - it was a much bigger problem in the 70's and 80's, and even in the 90's. Lately as fewer people smoke and those who do mostly do it outside, it's not as big a factor. You can always tell when you open a machine that's been in a smoker's home though - the dust and dirt inside is almost sticky. The dirt cleans out but the residue is tacky and difficult to remove, even with isopropyl.

 

Good video - I watched it a few hours ago. If it ever stops raining and gives us a sunny day in the next couple weekends, I intend to try some lightening experiments of my own with a couple low-value bits I have around the house.

[ToddL]

I read through the comments to the video. One person said if you see a computer that is yellow only on one side, it's actually the non-yellowed part that was in the sun. Several others mentioned that their computers turned yellow while stored in the attic (heat but no sun).

[_The Doctor__]

and this is why I never used the peroxide methods people flocked to... I had better de-yellowing results by washing the stuff on an overcast day in the back yard, dirt, oils, smoke tar- what have you- came off nicely, and I didn't get sun burned, the plastics never got brittle, and the they all stayed nice and clean. I never put them in direct bright sunlight and I never bleached them... it sounded destructive to me no matter how much gobbledy-guk people were spewing.

 

All's well that ends well !!! Glad I didn't follow the pack.

[jowi]

and this is why I never used the peroxide methods

No it's not. This implies you knew this all along. Why didn't you tell us? Because... you did not know. So no, this is NOT why you never used the peroxide method.

[_The Doctor__]

You must be kidding, the only like I more than likely gave for the entire thread would be to cleaning and disassembly in a post, and the only active argument I participated in was to the color of the computer more than likely about it being too light or even someone painting it. Lastly my big hint to what I thought about using accelerators and all this crap was a simple 'slow and steady wins the race' comment. Since I think my lack of likes, dislike of over bleaching changing the color, and my caution for folks to slow down. I really didn't think I needed to go to war against the thread and deal with crap that would come like your post just did.

[_The Doctor__]

I am quite sure some 'chemist' will come along and contradict one way and then the other. You have not seen one posted retro-bright picture from me. You might consider some of that, so if a person goes all ape sh*t against something such as this myself they would be all wrong, and when I/they gently caution... I/they are wrong. I guess it's both good I'm wrong and I haven't bleached or made brittle any Atari Stuff. You will however read in many posts littered about, how cleaning and getting smoke tar and other things off made a bigger difference to me than all this other gobbledy-gook. Consider that and why I don't give instruction to do anything otherwise. So d*mned if you do, d*mned if you don't. Picking a place somewhere in between will still get you the ole' internet smack job.

 

This appears to be the most I've posted in this dreaded thread. Now you see why I'm not a cheerleader and my 'Spidey' sense still tells me to stay away from it.

Edited May 7, 2019 by _The Doctor__

[tjlazer]

Since the yellowing returns in a year or so I got sick and tired of obsessively dismantling the computer completely to redo the Retrobrite treatments! Since I have a lot of Commodore and Atari and Apple computers this became a problem for me. I can find other things to do with my time. I found a much easier way that works pretty well as long as you are careful. I don't dismantle the computer or keyboard at all. I do it all in place with creme conditioner slightly watered down a bit and a brush. I get the excess off the brush as much as I can and simply brush the case and keyboards (and this way I can avoid the labels, etc) and leave it out in the sun. You don't apply much at all just a light coating that gets the keys and case wet. No caking it on! I reapply every 15-20 minutes and do the treatment for 4-6 hours and repeat the next sunny day as needed. I can remove the yellowing in 4-6 hours on a nice hot sunny day. When done you just wipe it down with some cleaner and dry it off. Have't had any issues or spillage in to the keys as I make sure to keep the brush drip free when applying.

 

Here are a few quick videos I did:

 

Part 1:

 

Part 2:

Edited May 8, 2019 by tjlazer

[Mclaneinc]

Going to try the sun only version at some point when it gets a bit brighter here in the UK, all I need do is set up a sniper post for the locals chancing their arm

 

I'll just do case shells rather than a full package, should keep the light fingered away..(no garden as we are a flat, no safe space beyond our mini balcony and the locals steal anything to save comments)

 

If that fails I may go the Jowi or TJlazer road depending on UV lamp cost or sun availability UK wise..

 

Hopefully the sun works because I have, an Amiga, a C64, an 800, a 130XE, 3 disk drives for the Atari, a US Snes and almost forgot the Amiga 1200, all which need a good colour refresh...Probably won't bother with the 1084 or the 8852 monitors..

 

That's a LOT of sun

 

Also worried about the extreme UV as we have no little rooms where it can be done on its own (small flat) and I have eczema and Rosacea (it flourishes the face red) which with eczema is annoying and don't want to aggravate it..

Edited May 25, 2019 by Mclaneinc

[_The Doctor__]

http://atariage.com/forums/topic/291210-new-technique-for-whitening-yellowed-plastic/?p=4277021

have fun.

[Mclaneinc]

Wow, that's a big list and a worry...Got enough going on here health wise without 'pushing my luck'..

 

I may just enjoy my old yellowed machines as they are

 

Thanks good Doctor..

[griff3125]

I put mine out in direct moonlight for 12 nights straight......results may vary....

 

[+Stephen]

Man - that sure looks nice.

[mimo]

Time to unsticky this thread now I think, looks like there is a new kid on the block, just use sunlight

 

[Colleton]

I tried the sun only "light brighting" last weekend on a newly purchased 1050.  It had a bit of yellow on the top and a bit more on the back and along one side.

 

Over the course of a semi-cloudy Florida summer afternoon all of the yellowing was eliminated.  It worked very, very well for me.

[flashjazzcat]

Time to move to the US, then. Twenty or thirty hours in UK sun did nothing for two of my yellow 1050 cases.

[+DrVenkman]

25 minutes ago, flashjazzcat said:

Time to move to the US, then. Twenty or thirty hours in UK sun did nothing for two of my yellow 1050 cases.

That ain't gonna necessarily help. Zero shortage of bright sunlight here in Tennessee this summer but it did zilch for lightening up the "sunburned" side of these keys on this 64C.

 

However about 30 hours soaking in a clear container filled with tap water and about 8 ounces of 40Vol clear liquid peroxide hair product worked wonders. I put the keys inside a medium/large food container, submerged them in warm water, poured in the peroxide, then covered the container in clingwrap plastic film. I put it out in the sun around noon and let it sit there all afternoon, going out every couple hours to stir it around and release the bubbles from under the plastic film. I left it out all night and again the next day until 6:00 pm. I'm going to use the same method on the larger case top when I get a larger clear container to use and some more peroxide product.

 

 

[flashjazzcat]

Oh well: eventually I slapped a coat of 40 vol creme peroxide on both cases and they were done to perfection in two hours. I was enticed by the possible longevity of the sun-only results, but I didn't realise that meant it takes so long to process the case, you'll die of old age before the plastic has a chance to discolour again.