Removing yellowing from Amigas with peroxide

[r.cade]

That is very interesting. I wonder if it's the heat from the sun that does it and not the UV? I tried with just peroxide and left one for weeks with no change, but it was room temp. I guess someone needs to try putting one in the oven at a low temp (120-150 fahrenheit) and see if that causes the reaction.

[turrican9]

Originally Posted by r.cade

That is very interesting. I wonder if it's the heat from the sun that does it and not the UV? I tried with just peroxide and left one for weeks with no change, but it was room temp. I guess someone needs to try putting one in the oven at a low temp (120-150 fahrenheit) and see if that causes the reaction.

I suspect it's mostly the heat from the sun that does it, yes. This is also why I believe, as I mentioned earlier I've read about people that don't get much change with a UV bulb in 36 hours +. I think it's because they leave it in room temp and UV light in itself without the temp increase will not do much. While people that make boxes with UV light inside and tinfoil to cover the walls seems to have great success probably because of the heat generated inside the box.

I have proof enough with these Amiga 500 keys. There is no sun at this time of the year here in north of Norway that could have come through the window (which is covered by curtains anyway). And I have no UV light source here. So the only explanation is the heating cables in the floor. The keys went from quite badly yellowed to almost mint condition in 48 hours. But I think they were about finished after about 30 + hours from the inspections I did underway. Also much safer method than the sun
because out in the sun there is great danger of irreversible bleaching/blooming of the plastic. Seen it myself.

Edit: Also have a tank mouse on the floor now that still had some yellowing after treatment in the sun last spring. Has been on the floor for over 24 hours now I think. so will check it tomorrow to see if there is much change. Think I can already see quite a bit change through the plastic wrapping.

[turrican9]

So the Tank mouse looks 95% perfect after 3 days on the floor. I can barely/if at all see any yellowing on the top and the back of it. Again, no UV light source only been on the floor (with heating cables) wrapped in plastic and cream peroxide.

[amigasith]

Hi turrican9, inspired by your experiments with heat, I started my own I recently bought a pretty yellowed A500 keyboard that I have now started to treat with retrobright and heat - leaving it on a floor that has floor heating. Not heat wires like you have, but water pipes inside the floor. I guess it's not as warm as your floor, but still...

After 24 hours, I *think* that it has already started to become whiter. But I will leave it on the floor another 24 hours and then have a second look. I took a "before" picture, comparing it with a pretty white other A500 I have. I'm really curious about the outcome of this experiment

If the heat method turns out to work just as well as sunlight, I guess that the "retrobright season" will move from summer to winter Another plus in my opinion would be that this method seems to be much less aggressive than sunlight.

Next post in 24 hours

[turrican9]

Originally Posted by amigasith

Hi turrican9, inspired by your experiments with heat, I started my own I recently bought a pretty yellowed A500 keyboard that I have now started to treat with retrobright and heat - leaving it on a floor that has floor heating. Not heat wires like you have, but water pipes inside the floor. I guess it's not as warm as your floor, but still...

After 24 hours, I *think* that it has already started to become whiter. But I will leave it on the floor another 24 hours and then have a second look. I took a "before" picture, comparing it with a pretty white other A500 I have. I'm really curious about the outcome of this experiment

If the heat method turns out to work just as well as sunlight, I guess that the "retrobright season" will move from summer to winter Another plus in my opinion would be that this method seems to be much less aggressive than sunlight.

Next post in 24 hours

Nice to hear I have just been doing a extremely yellow Amiga 500 keyboard from ebay and it sat on the floor for almost 5 days I think. Alot of the yellowing is gone but it needs one more go. In fact I am wondering if the cream peroxide was not working anymore (did not look completely dried out) after a certain number of days and it needed to be re-applied. I also bought a good looking Amiga 500 case. Only problem with it was extreme yellowing on the left side, where the expansion port is. I think it has been on the floor for two days now, and alot of the yellowing is gone.

This method works, but takes time. But within 24 hours you should start to see a difference. And on the 2nd day you should definetly see a quite big difference. So I am wondering if this slow process will do so the yellowing takes longer to come back, because the peroxide has time to go deeper in the plastic. Only time will tell.

[Mr B]

Dumb ass idea. Save a discolored part for the summer. Or, if it's summer right now, try this.
Wrap it all in an extra layer of saran wrap, and put it in a black garbage bag. Blow it up enough to "stay of" the package, and tie it, or use zip-ties to close it up. Put the whole darn thing in the sun. It should be hot and toasty inside, but no UV. It should beat "floor heating" by miles, and, if it's temperature, beat just placing it in the sun as well.

However, i'd try it with a part that it wouldn't be the end of the world if you "over" bleached. Since it might be hard to know when to stop the treatment, i mean.
I suppose the same effect could be reached with a sauna, but...

Just thinking, be careful with your gear.

[amigasith]

Alright... Posting this a bit more than 24 hours later, but still...

Another lesson learned in my Amiga life: Never underestimate the power of the "heat" retrobright method What happened? Well... I left the keyboard for 48 hours on the floor and now the dark keys on the keyboard have whitened beyond their "natural color". In addition, some of the dark keys have "marmorated", meaning there are white random patterns visible in the dark surface of the plastics.

There are 2 factors that have to be considered I guess: time and amount of applied retrobright mixture. I applied retrobright 3 times on the 1st 24 hours and 2 times the 2nd 24 hours. Since I believed that the heat method is not as aggressive as the sun method, I kept on re-applying retrobright even in the 2nd 24 hours. So in retrospect, I should have either applied less retrobright or let the keyboard on the floor for a shorter amount of time. When I retrobrighted my A4000 keyboard this summer, I also applied retrobright 3 times, but I only let it in the sun for around 10-12 hours and the result was close to perfect.

Anyway - people reading this should take it as a warning Never underestimate the power of the "heat" retrobright method

Here is a picture "before":



It's not really visible on the picture, but the keyboard was *really* yellow before the treatment. The photo doesn't really reflect the real state before the treatment.

And here is a picture "after":



The keyboard looks nice on the picture - there is almost no visible difference to the reference keyboard. However, if you look very closely, you can see that the dark keys have started to whiten beyond what is normal.

Cheers

[turrican9]

Originally Posted by amigasith

Alright... Posting this a bit more than 24 hours later, but still...

Another lesson learned in my Amiga life: Never underestimate the power of the "heat" retrobright method What happened? Well... I left the keyboard for 48 hours on the floor and now the dark keys on the keyboard have whitened beyond their "natural color". In addition, some of the dark keys have "marmorated", meaning there are white random patterns visible in the dark surface of the plastics.

There are 2 factors that have to be considered I guess: time and amount of applied retrobright mixture. I applied retrobright 3 times on the 1st 24 hours and 2 times the 2nd 24 hours. Since I believed that the heat method is not as aggressive as the sun method, I kept on re-applying retrobright even in the 2nd 24 hours. So in retrospect, I should have either applied less retrobright or let the keyboard on the floor for a shorter amount of time. When I retrobrighted my A4000 keyboard this summer, I also applied retrobright 3 times, but I only let it in the sun for around 10-12 hours and the result was close to perfect.

Anyway - people reading this should take it as a warning Never underestimate the power of the "heat" retrobright method

Here is a picture "before":

Attachment 51166

It's not really visible on the picture, but the keyboard was *really* yellow before the treatment. The photo doesn't really reflect the real state before the treatment.

And here is a picture "after":

Attachment 51167

The keyboard looks nice on the picture - there is almost no visible difference to the reference keyboard. However, if you look very closely, you can see that the dark keys have started to whiten beyond what is normal.

Cheers

How much heat did you put on? What temperature did the floor have? Also, what kind of cream peroxide mixture are you using? I just use regular 12% 40 volume cream peroxide with no other mixture. Also, I have the heating cables on so that I keep maybe 23 - 25 Celcius in my retro room. It's not like it's burning hot on the floor. I have not noticed any blooming effect on my grey keys as I did see when I did this out in the sun. I did not re-apply cream peroxide until 3 - 4 days, or maybe even more in some cases.

[amigasith]

Originally Posted by turrican9

How much heat did you put on? What temperature did the floor have?

The water in the water pipes has very low temperature - usually it is not more than 32 / 33 degrees Celsius. I did not measure the temperature of the floor, but it was *far* away from being hot. I would say hand-warm at most.

Originally Posted by turrican9

Also, what kind of cream peroxide mixture are you using? I just use regular 12% 40 volume cream peroxide with no other mixture.

Same here - 12% 40 volume cream peroxide. The only thing I add is a little bit of Vanish Oxy Clean to get the foaming going. But as said, I have used this mixture on quite a few other items like my A4000 keyboard and it worked very well.

As written above, I think I really should have applied either (a) less retrobright or (b) stopped the treatment after 24 hours.

[turrican9]

Originally Posted by amigasith

The water in the water pipes has very low temperature - usually it is not more than 32 / 33 degrees Celsius. I did not measure the temperature of the floor, but it was *far* away from being hot. I would say hand-warm at most.



Same here - 12% 40 volume cream peroxide. The only thing I add is a little bit of Vanish Oxy Clean to get the foaming going. But as said, I have used this mixture on quite a few other items like my A4000 keyboard and it worked very well.

As written above, I think I really should have applied either (a) less retrobright or (b) stopped the treatment after 24 hours.

I never tried to mix in Vanish oxy clean but I seem to remember I read some people gave a warning about using it because it could cause blooming effect one the plastics. Also, maybe some plastics are more sensitive than others. All these Amiga keyboards, cases etc.. are not created 100% equally.

But I would stay away from that Vanish Oxy clean if I were you. Just to be on the safe side.

Anyway, we have proven that one don't need either sun or artificial UV light. Heat is enough.

[amigasith]

Originally Posted by turrican9

Also, maybe some plastics are more sensitive than others. All these Amiga keyboards, cases etc.. are not created 100% equally.

Exactly my thought! The A500 keyboard I just treated with retrobright and the heat method is a Samsung made one and the plastics "look and feel" different from the Mitsumi ones.

Originally Posted by turrican9

But I would stay away from that Vanish Oxy clean if I were you. Just to be on the safe side.

That's my lesson learned, too...

Originally Posted by turrican9

Anyway, we have proven that one don't need either sun or artificial UV light. Heat is enough.

Full ack

[Signman]

Just thinking, I might try this method on my teeth.
Just smile at the sun for a few hours.

[turrican9]

Originally Posted by Signman

Just thinking, I might try this method on my teeth.
Just smile at the sun for a few hours.

Or put your face with mouth open and teeth against a floor with heating cables for 3 or 4 days. Make sure you also cover your teeth with plastic wrapping so the cream peroxide don't vaporize too fast.

[turrican9]

So bought this Amiga 500 case on ebay. It was almost perfect according to the seller except for the expansion port side which had what I would call extreme yellowing. That side of the Amiga must have been standing close to a heat source or something for many years.

Anyway, I re-applied cream peroxide 3 times over the span of... well, must have been more than 14 days to get rid of this extreme yellowing. I did the whole case the first time. It turned out much whiter than a normal Amiga 500. Case was made in Germany so may have been that it was very white when it was made. The last two sessions I concentrated on the expansion port side which was still yellowed. Of course using the method on the floor with heating cables just keeping normal room temp. No UV light.

Before (sellers picture)




After (My picture)

[PeteAU]

For any Aussies, I picked this up at Aldi for $3.99. It's 6% hydrogen peroxide and it worked a treat on my A500 case in about 3-4 hours. Didn't mix it with anything.

[dJOS]

Originally Posted by PeteAU

For any Aussies, I picked this up at Aldi for $3.99. It's 6% hydrogen peroxide and it worked a treat on my A500 case in about 3-4 hours. Didn't mix it with anything.

Nice, that's way cheaper than vanish oxyaction and the peroxide content is virtually identical.

How thick is the gel?

[manicx]

Newbie to try and remove yellowing (even though I asked in the past I think) and need help. I have an Amiga 2k keyboard (connected to my A4k) and an A1200 that have yellowing. The former is mainly the case, the second are the some keys.

For a start, I have a place for hair-saloon supplies very close. But I don't know what is better. I've read about creams and also about liquid only that the cases/keys are having a bath under the sun .

-What gives better result? And especially in cases, I am interested in uniformity.
-Recipe (for both cream or liquid solution).

Any tips are appreciated. I'll use the hot Greek sun (whenever it comes out because at the moment we enjoy the not so hot Greek snow) for UV/heating.

[nobody]

I did it once, around 2010 the Amiga became white again and then yellow again after 1-2 years. Now it is painted black & connected to a black Philips 14" tv

[demolition]

Originally Posted by manicx

Any tips are appreciated.

Just read through the posts in this thread. There are lots of tips from people who have tried different things. Dos and don'ts.

[turrican9]

If some of my Amigas go yellow again I don't think I will bother using cream peroxide again. I will just leave them as they are.