Brick de-yellowing techniques

[AmperZand]

^Interesting. I noticed mine got whiter, but I didn't notice a different feel to the surface of the bricks/figures when I did it. Although, I only used 3% peroxide and no vanish oxy clean. I wonder if that made a difference?

It's possible. Vanish Oxi Crystal White is a cleaning product after all, so it could be that using it makes the bricks super-clean, i.e. even cleaner than new parts or ones washed in washing up liquid. I don't think it's related to the concentration of the hydrogen peroxide. I could test the hypothesis by washing some parts in Vanish Oxi Crystal White and water instead of hydrogen peroxide and seeing if I got the same change of feel. If I have time, I'll try it and post the results.

[rodiziorobs]

An alternate method to the hydrogen peroxide soak is using Magic Eraser:

On the left side, I scrubbed for about a minute or so, and the right side remained untouched. The left is still a bit yellowed, but additional scrubbing gets it whiter. Since the Eraser is just a soft, dry chemical block (activated and dissolved by water), it didn't scrape or scratch the surface at all.

The downside is that since you have to scrub, it is hard to get even around the edges and in grooves, as shown on this palisade panel. I wouldn't even try it for a studded surface-it would shred the Eraser before you could make any real progress.

Also, I the piece shown above is yellowed from the sun, and not from the presence of bromine as detected in bricks from before about 1994 or so; I tried cleaning some of those with Magic Eraser but noticed no difference.

So, its not a perfect method, but it works okay.

Edit: this was taking too long, so I just went ahead with the peroxide; better results with less work.

Edited September 27, 2014 by rodiziorobs

[R0Sch]

Hello all,

I want to tell you about my experience with hydrogen peroxide and how I got to whiten my badly yellowed LEGO parts.

After I have read in numerous forums how yellowed plastic can be whitened with Retr0bright, bleaching and other methods, I thought that I would try the least harmful method and bought a 1L bottle of hair developer 12% H2O2 from amazon (brand M:C PEROXIDE 12.0 %). I wanted the creamy one to be able to brush it on the parts, but the merchant sent me by accident the fluid version, which turned out to be much better because I was able to immerse the parts fully in some transparent plastic recipients.

The liquid itself is a mix of chemicals (Water, Hydrogen Peroxide, Sodium Salicylate, Etidronic Acid, Tetrasodium EDTA, Phosphoric Acid, Tetrasodium Pyrophosphate, Disodium Phosphate), but I couldn't notice any britteling effects on the parts.

Depending on the amount of yellowing, I left the parts in the peroxide between 1-4 days, because I didn't have a good place at the window where the sun shines all day long. But I checked twice a day to see the progress and gradually took out parts that where satisfyingly white.

Here are the before/after pictures:

http://www.brickshel...ry.cgi?f=549698

As you can see the parts look almost like new. #12 shows all the parts I "cleaned" this way.

I was such a fool till now for ordering expensive replacement parts for old Technic sets that had yellowed rims or bricks. My 8880 looks so much better now.

Amazing what H2O2 + a little UV light can do!

[AmperZand]

Depending on the amount of yellowing, I left the parts in the peroxide between 1-4 days, because I didn't have a good place at the window where the sun shines all day long. But I checked twice a day to see the progress and gradually took out parts that where satisfyingly white.

You should try adding Vanish Oxi Action Crystal White. It will reduce the time from days to hours. I used H2O2 + Vanish Oxi Action Crystal White + sunlight to turn distinctly yellowing parts into ones that were as white as new in an afternoon. I don't have before pictures, but I restored this set using a mix of used and new parts. You now can't tell which are which.

[Navy Trooper Fenson]

Depending on the amount of yellowing, I left the parts in the peroxide between 1-4 days, because I didn't have a good place at the window where the sun shines all day long. But I checked twice a day to see the progress and gradually took out parts that where satisfyingly white.

So you didn´t even have to put the parts out in sunshine and just leaving the parts long enough in the liquid works? I would like to order the same liquid you used for myself and I wonder if you have yet experienced any side-effects. What would be the worst case scenario? Did you also try cleaning yellowed pieces with printing or stickers on them?

I would want to use the liquid to treat my 2008 Death Star model and some Stormtrooper minifigures. Not every part is yellowed but a number of them have some discoloration and I suspect the ones that aren´t yellowing now will start to yellow not shortly after so I would like to have a solution that doesn´t involve sunbathing the pieces as I don´t have enough room or time for that.

Edited February 25, 2015 by Navy Trooper Fenson

[mpfirnhaber]

I haven't done stickers but I've cleaned plenty of printed parts with no problem. Also old light-and-sound plates with the metal contacts in the bottom.

I dump all the parts I want to treat into a round plastic tub, add a small spoon of Oxi Clean and one bottle of 3% hydrogen peroxide, and leave it outside on my balcony for 24 hours.

Be aware that older parts will get a LOT squeakier after treatment, and the clutch strength will increase quite a lot.

[Plastikean]

(I'm assuming it's best to revive this topic with my question, rather than posting a new thread as they seem to get merged back here anyway.)

I don't suppose anybody's found a method to undo fading of gray parts that have been treated for yellowing?

For background, as well as to provide an update with my own experience using the techniques discussed in this thread: I've had great success using just a straight 3% solution of hydrogen peroxide—no OxyClean, no higher-strength solution from a beauty supply store, just the bare basics. I've been treating parts with minor to moderate yellowing; nothing so severe that you'd start to call it tan or brown. Using a clear container and lid, placed in direct sunlight (on a table that happens to be white, which probably helps), I've been seeing results in as little as an hour or two for slight yellowing, perhaps half a day for worse cases. A couple of very stubborn parts got treated twice, and a couple others never responded to treatment at all (specifically, 1x20 gear racks, and the soft part of flexible hoses—the rigid ends did respond and so I now have yellow hoses with white ends).

I did know that fading of light gray parts was a danger, but since I was getting the yellow out in such a short time, I assumed the parts wouldn't be in long enough to risk fading. (Why I thought that part of the process wouldn't be similarly accelerated, don't ask. ) So now I have a piece of straight monorail track that has a chalky appearance on the top and one side. The part had been more yellowed overall than most other gray parts, and I assume that the faded side is the same one that was originally yellowed. Still, this was the only gray part I treated that showed the fading effect.

I'm assuming this damage isn't reversible the way yellowing is, but maybe someone out there knows something I don't and I'll be happily surprised!

[IvanTheBuilder]

I know how to get the green bricks back...just expose to radiation.

[zux]

I know how to get the green bricks back...just expose to radiation.

And my mind keeps imagining how you are planning your trip to Chernobyl to get your green bricks back

[grum64]

You should try adding Vanish Oxi Action Crystal White. It will reduce the time from days to hours. I used H2O2 + Vanish Oxi Action Crystal White + sunlight to turn distinctly yellowing parts into ones that were as white as new in an afternoon. I don't have before pictures, but I restored this set using a mix of used and new parts. You now can't tell which are which.

I'll have to give this a go with the wheels on my 8880. They're not too bad at all but it'd be nice to see them back to their original glory.

Thank you for sharing the info.

[IvanTheBuilder]

And my mind keeps imagining how you are planning your trip to Chernobyl to get your green bricks back

.

Knew u would say that.

[Hinckley]

Does anyone know if this technique is safe for transparent pieces? I have a glued model to clean for a client and I would like to just dump it in a tub of peroxide and Oxy–Clean, but I'm unsure if it will negatively effect the trans–light blue window pieces in the model. It would not be easy to remove them before cleaning and even harder to get them back in.

[BubbaFit45531]

The other day, I had a transparent red 1x1 brick crumble in two. Didn't put any chemical cleaners on it. It was old and stored in plastic tub inside a tied trash bag.

[Hinckley]

7 minutes ago, BubbaFit45531 said:

The other day, I had a transparent red 1x1 brick crumble in two. Didn't put any chemical cleaners on it. It was old and stored in plastic tub inside a tied trash bag.

So, that basically has absolutely nothing to do with what I asked, right?

[AmperZand]

22 hours ago, Hinckley said:

Does anyone know if this technique is safe for transparent pieces? I have a glued model to clean for a client and I would like to just dump it in a tub of peroxide and Oxy–Clean, but I'm unsure if it will negatively effect the trans–light blue window pieces in the model. It would not be easy to remove them before cleaning and even harder to get them back in.

To be honest, I'm not sure and unfortunately I live too far north to test it this time of year: there isn't enough strong sunlight.

That said, in addition to having used Oxi Action Crystal White with H2O2 and sunlight on LEGO as mentioned earlier in this thread, I have used Oxi Action Crystal White with a small amount of water for non-LEGO applications. It forms a whitening, slightly abrasive paste. I suspect that if you used enough H2O2 such that none of the Oxi was left visibly in suspension, that none of the abrasive qualities of the Oxi would remain. My guess is that Oxi Action Crystal White + lots of H2O2 + sunlight would have no effect on transparent LEGO pieces except to make them squeaky clean.    

 

[Forresto]

What is the best kind of lighting that will cause the least amount of yellowing on Legos?

Is it all colors that yellow? Such as the Light Blue Grey? Would a bucket or box help to slow this? 

Edited January 10, 2017 by Forresto

[RetroInferno]

LED lights, they don't emit UV radiation, which is the main cause of yellowing bricks. 

I can't say if Light Bley can yellow as my sets having this color are mostly recent, but light gray sure does

[zux]

14 hours ago, RetroInferno said:

LED lights, they don't emit UV radiation, which is the main cause of yellowing bricks. 

Well, it is quite the opposite - LEDs DO emit some UV.

[Hinckley]

I don't have sunlight the last few days either, but the chemical itself did not negatively effect the transparent piece I tested.

[Vindicare]

I've read the last two pages...and it seems the common practice is 3% hydrogen peroxide & Oxi-Clean. I'm about to attempt this for the first time on dark grey tiles, from Green Grocer. For that amount of pieces, how much of each is best? Using, lets say, a typical 8oz paper cup, how much peroxide how many tablespoons of Oxi-Clean?

[AmperZand]

2 hours ago, Vindicare said:

I've read the last two pages...and it seems the common practice is 3% hydrogen peroxide & Oxi-Clean. I'm about to attempt this for the first time on dark grey tiles, from Green Grocer. For that amount of pieces, how much of each is best? Using, lets say, a typical 8oz paper cup, how much peroxide how many tablespoons of Oxi-Clean?

Not a paper cup!  Use a clear glass jar without a lid. Make sure you have at least enough H2O2 to cover the parts. The Oxi will froth quite a bit, so you don't want to go crazy with it. The volume of Oxi equal to a few 2 x 8 bricks should be more than enough. You can always start with a small quantity and add more as required. The froth will likely spill over the lip of the glass, so you'll want to put the glass jar on a tray or in some kind of container.

Note that the H2O2 and Oxi mix is toxic if ingested, so you'll definitely want to keep it away from kids and pets. Also, you probably shouldn't use the jar again for food/drink even after you have cleaned it.

 

Edited April 28, 2017 by AmperZand

[Vindicare]

5 minutes ago, AmperZand said:

Not a paper cup!  Use a clear glass jar without a lid. Make sure you have at least enough H2O2 to cover the parts. The Oxi will froth quite a bit, so you don't want to go crazy with it. The volume of Oxi equal to a few 2 x 8 bricks should be more than enough. You can always start with a small quantity and add more as required. The froth will likely spill over the lip of the glass, so you'll want to put the glass jar on a tray or in some kind of container.

Note that the H2O2 and Oxi mix is toxic if ingested, so you'll definitely want to keep it away from kids and pets. Also, you probably shouldn't use the jar again for food/drink even after you have cleaned it.

 

Well yeah, the paper cup was just what popped in my head.  Thanks for the info. I probably will start small, I need to do Cafe Corner & Market Street too, to start. So, I won't need to fill it up all the way. Is just a tablespoon of Oxi enough? Or does the amount depend on how much peroxide is used?

[rodiziorobs]

I didn't use any Oxi when I did it on my white bricks, just equal parts water and H2O2 (3%), put the jar on the windowsill in the sun for a day and it worked fine.

Edited April 30, 2017 by rodiziorobs

[Raystafarian]

Apologies for the ridiculous bump here, but this is part of the index thread.

I heated some baking soda (sodium bicarbonate [NaHCO₃]) on the stove until it stopped bubbling, which (simply put) converted it to sodium carbonate [Na₂CO₃]. This is also known as soda ash, and as far as I can tell it's the active ingredient in OxiClean.

After it cooled, I mixed 1/2 tablespoon of that with 1 cup hydrogen peroxide (3%) for a small batch of plates in a clear food-grade plastic container, out in the direct sunlight. Only took maybe a total of 6 hours to de-yellow the plates. I could see the difference in 3 hours and I planned to just go for 7 hours, but I didn't need to. It might have taken only 4 or 5 hours. 

Just thought I'd add in some specifics for anyone looking through this in the future.

[Grover]

Nice work, and thank you for sharing!  The more data we have in this arena, the better versed we will be in figuring out out to solve the yellowing issue.

FYI, the active ingredient in OxyClean is sodium percarbonate, 2Na2CO3•3H2O2.  When you throw it in water, it releases hydrogen peroxide, which is where it gets its oxidizing power.  You essentially made OxyClean (minus any extraneous surfactants that the manufacturer may add) by adding hydrogen peroxide to a carbonate solution.  I'd be curious to know if your method with the base (sodium carbonate) was any more or less effective than the pure 3% hydrogen peroxide solution alone.  I'd be reluctant to start adding bases to the bricks if I could help it.  I would be even more reluctant to use pure OxyClean, as it may contain surfactants that could have interactions with the polymer or plasticizer (or even the flame retardants) in the ABS.  Great job, and let us know if you try any more experiments!