Guide to removing yellowing of plastics

[tonyyeb]

Hi all

After reading about the process and seeing some great results I decided to try this process on a mouse case. It didn't come out as I expected (http://eab.abime.net/showthread.php?t=38821). So after reading further (http://eab.abime.net/showthread.php?t=37808 and http://www.vintage-computer.com/vcfo...light=peroxide) I tried again on an A600 set of keys. So this is a guide of how I did it:

You will need:

Eye protection (goggles of some kind from motor factors will do)
Rubber Gloves
Lamp (Asda SmartPrice £2.98)
UV Bulb (Maplin £8.99 http://www.maplin.co.uk/Module.aspx?ModuleNo=33124)
Washing up bowl
Towels
Hydrogen Peroxide (Stronger the better - I used 30% (100vol). Available in various forms and from various places, Chemists, Hair Product sellers etc... WARNING: Anyone wanting to clean plastics should NOT be mixing peroxide (or most other cleaning products for that matter) with bleach; the worst case is that Chlorine gas can be given off; this was used as a poison gas on soldiers in WW1.)
Vanish Oxy Action (Asda - £3.98 a tub)
Blu Tac


The Process:

Take an A600 with yellowed keys (or any bits of yellowed plastic):


I stripped the keys and placed them in the bowl


I would recommend weighing the keys down with a bit of blutac stuck underneath each key.

Place the bowl over the towels.

Then pour in the Hydrogen Peroxide. I used about a litre to just cover the keys. I added about 1/4 of a tea spoon of Vanish Oxy action. It was spread evenly over the contents of the bowl.

Then I switched on the UV Lamp and placed it over the bowl.


I checked on it about every 30 mins but this was maybe a bit over cautious / curious!

This is how the L key started with the underside of another key shown to show what it should look like:


This is the keys after 8 hours. The A key was weighed down and shows a slight improvement over the L. The 1 is obviously an untreated key.



To see more pics of the process view my album: http://eab.abime.net/album.php?albumid=88

Thanks for Merlin for tips and help.

[Merlin]

OK, here's the roll-call of people who made all of this possible:-

Luzypher and AMike of a1k.org, for the original idea;
Kristian95, for bringing the idea to EAB;
Rkauer, for helping me make sense of the plastics engineering side of things;
Lorne of Vintage Computer Forums, for his experiments;
Tonyyeb and TheCorfiot of EAB, for their experiments;
Merlin, for bringing TAED to the party and making sense of the science of how it works;

and.....

All of the contributers to the original EAB post, you all helped to make this idea take off. Now everyone can benefit from your collective work.

K+ and Props to all.

AWESOME!!!! (c) Zetr0

[tonyyeb]

Thanks for adding the credits Merlin. I had no idea who started it all but anyone who has done this process or will be doing this process has these people to thank.

[rkauer]

@Merlin: no need for that, m8.

We amigans deserves all the good we can give to each other. Without the support of this board/very good chaps, I never will go that far.

to all you people!

[illy5603]

Here is a dumb question. I live in Northern California, it is still super hot and sunny out. Do I need a UV bulb or can I just use the sun? I imagine living in Hull you are gonna need a bulb! :-)

[tonyyeb]

Originally Posted by illy5603

Here is a dumb question. I live in Northern California, it is still super hot and sunny out. Do I need a UV bulb or can I just use the sun? I imagine living in Hull you are gonna need a bulb! :-)

Lol! We need all the artificial support we can get! Sunlight will do the job.

[Merlin]

Originally Posted by illy5603

Here is a dumb question. I live in Northern California, it is still super hot and sunny out. Do I need a UV bulb or can I just use the sun? I imagine living in Hull you are gonna need a bulb! :-)

Sunlight should be fine mate, and you should be able to get fantastic results in six to eight hours, based on work Lorne has done in Arizona. Look at the Osborne 1 case pictures in the other thread on this subject

We had a big yellow thing in the sky over Manchester a few weeks ago, we were wondering what is was and we thought it was a UFO; us Mancunians are amphibious you know and we don't like it too hot or dry....mind you, the rain was warmer back then!



LOL

[Merlin]

More good info:-

Lorne reports that a batch of peroxide could be good for up to four days' use in sunlight conditions, this is based on the 35% grade. It's to be expected as the TAED catalyses the peroxide as well as the UV light; at least now, we have a flag in the ground as to how long you can use a solution before it's spent.

[tonyyeb]

Do people think this thread should be made sticky?

[Merlin]

The lads at VCF have suggested that we eventually make a Wiki article. I think that's a good shout...

[Zetr0]

I think thats a great idea, I can help by digging up some chemistry formulas

[DDNI]

You gotta bet we have MI5 checking EAB!!

[Merlin]

OK, Lorne has finished his Osborne 1, get a load of these......you cen definitely tell the before pictures from the after......

[Zetr0]

Now thats

F*CKING JOB DONE!!!

when you next chat to Lorne, tell him well done!

btw, how much is a pristine white Osborne 1 worth these days?

that reminds me Merlicious,

remember we were discussing Halogens the other day on the phone, do you think its wise to caution people on the use of Chlorine based products?

for those that dont know; Chlorine atoms will eventually replace the Bromine atom at the end of the molecular chain, Chlorine will still base with Oxygen and this is were serious problems start

Chlorine is about half the atomic mass of Bromine, this means that there is more room to move around molecularly speaking, with two Chlorine atoms instead of a single Bromine, when the Chlorine atoms attach to Oxygen atoms it is then this that destabilizes the Molecular Polymer chain and makes it brittle.

By using peroxide all we are doing is removing that Oxygen Atom that got stuck over time.

yes yes... formulas coming.... remember I am no Chem-ist

[T_hairy_bootson]

Can all variations and new information be added to the first post and then the thread stickied? Will be great when I finally get around to doing this not having to trawl through a massive thread of info. Or the wiki idea.

[Merlin]

@ Zetr0

Good call; Anyone wanting to clean plastics should NOT be mixing peroxide (or most other cleaning products for that matter) with bleach; the worst case is that Chlorine gas can be given off; this was used as a poison gas on soldiers in WW1.

@ THB

Don't worry, all of the information on here and over at VCF is being collated, along with some related Wiki articles. The whole thing will be put together into a dedicated Wiki in early October. I agree, there's a lot of information to sift through, there's been a lot of science abuse on the forums recently, long may it continue!!

[tonyyeb]

I've added the warning about mixing peroxide based products with bleach.

[rkauer]

Just remember that chlorine bleach is useful to clean the cover of wires (PVC).

If you have a bad shape keyboard wire, it is the bleach you must use on it. Also good for rubber balls (that one inside mice).

[Merlin]

Hey guys, here's an update...

Lorne over at VCF is going to try the 'gel' version of our magic formula. I have advised him to try gelling the mixture with xanthan gum, which is easily obtainable and should make a clear gel. We are aiming for a mixture that is brushable like emulsion paint. Lorne has ordered the xanthan gum, we are just waiting for it to arrive. He is going to add the gum after he has added the 'Oxy' to activate the peroxide solution.

Stay tuned....we aren't sure how this is going to turn out, but it's all good science abuse anyway....

[tonyyeb]

That sounds cracking! It would be great to brush on, leave 8 hours then wash off. Better than weighting stuff down.