Brick de-yellowing techniques

[antp]

You can find basic 3% hydrogen peroxide in most drugstores. Their intended use is for desinfecting wounds.

My problem is where to find a drugstore, as these seem to have disappeared here :D (there are pharmacies and supermarkets, I didn't check the first one but didn't found that in second one).

[SheepEater]

drugstore is a synonym for pharmacy.

[naf]

I just used this technique, figured I'd report my results. I recently purchased a used 6271 Imperial Flagship, which had a lot of yellowed bricks. Both of the plastic flags were very discolored, along with most of the white, blue, and light gray bricks. The minifigures were also discolored, mostly the admiral's bicorn hat and the torso's of the figs. I mixed up a solution of 2 cups of 3% hydrogen peroxide, about a tablespoon of standard oxyclean, and mixed them together until dissolved. I submerged all of the discolored parts in a clear bowl, placed a sheet of aluminum foil under the bowl to reflect light, and put it under a desk lamp for about 4 hours. At this point, all of the bricks looked brand new, even the flags were bright white again.

However, the minifigures seem unaffected. The backs seem to have gotten a little brighter, but the discoloring on the printing, and the white part of the admiral's bicorn have seen no noticeable improvement. Has anyone had any luck using retr0bright on minifigures? Maybe the plastic is of a different formula than regular bricks, or the fading is on the actual paint/printing on the figure, and has nothing to do with the abs plastic?

I should note that the retr0bright did not affect or fade any of the printed parts. I had a large and small Imperial flag, along with the minifigures, in the solution, and none of the printing faded at all.

Edited April 9, 2013 by naf

[Rare White Ape]

I went to my parent's place this evening and decided I wanted to dig out my Technic 8880 set and have a build, for old time's sake. Upon bringing it home and looking in the box, I was greeted with this:

Here is a 'white' 4x1 plate on top of a newer X-Wing:

And... wait for it! The same piece next to a new white element and a new tan element.

So I started this thread to see if anyone had any good tips or ideas regarding the cleaning and restoring of old pieces like this. I'd like to know about old grey as well, I have plenty of pieces in that colour that have turned into something closer to manky grey than their original splendour.

Also, how would one go about washing the dust off a thousand little Technic pieces without losing them down the drain?

I'd like to get stuck into this before I go ahead and assemble the set again.

[JopieK]

These guys have some interesting idea: http://www.brothers-brick.com/2009/08/30/how-to-clean-yellowed-lego-bricks-to-make-classic-space-sets-look-new-news/

[naf]

I used this retr0bright method on a used Eldorado Fortress. The parts were all yellowed like yours are. Having the bricks in the solution for 24 hours with a UV light on them made them all bright white again. Some of them are still a little yellowed, but I'm going to do another round of retr0bright on them to see if they can get brighter.

[SheepEater]

http://www.eurobricks.com/forum/index.php?showtopic=7167

[Rare White Ape]

Ah, I see that this question has been asked a million times before!

Thanks for the links guys, I appreciate it.

[Hopey]

Yo. I recently got hold of some of my pre-dark ages sets. The wheels from my 8868 "Rebel wrecker" were rather badly yellowed despite being in a box for most of the intervening 18 years or so, and I thought I'd have a crack at whitening them.

I found some 12% peroxide at the chemist and some Oxy-something laundry powder. The peroxide has some other stuff mixed in (ethanol, sodium laureth sulfate, some other stuff) which gives it a consistency something like shampoo. This proved to be a bonus, as I could apply it with a brush without having to muck about with xanthum gum or any of that in the retr0bright process, I just poured out about half a shot glass, mixed in a small sprinkle of oxy-whatever and applied it with a paintbrush. I left them out in the Australian winter sun all day, and repeated it the next day.

Here's the before:

And here's the after:

Not bad, in my opinion. Before, the part that was beneath the tyre was clearly much whiter than the part that was exposed. Now it's difficult to tell the difference. They could possibly do with another day, but I don't think I'll bother.

Now to do the wheels of the 8880 I picked up last year...

[CisFran]

I chanced upon this cleaning process on the facebook page of Philippine LUG.

Link:

https://www.facebook...&type=1

He used zonrox/clorox bleach and hydrogen peroxide, 2 tbsp each combined with 1.5 liters of water.

Submerged the parts for 8 hours. He mentioned the cleaning solution is ok for figs that turned yellowish,

it works well for both multi-colored minifigs and bricks as well. Colored bricks will appear more vibrant and shiny after the treatment.

On the left is the one cleaned/bleached after 8 hours. Notice the prints are still ok.

Edited September 15, 2013 by francisalmario

[Saint]

just nabbing this topic to find it in future reverence !!

[Daniel-Technic]

Hi.

Sorry to bring this up. Has anyone who done the method of de-yellowing a few years ago, is the same pieces that was treated still the same or gone back to yellowing?

I have some white technic beams I can have fun treating.

Thanks

Daniel.

[sithewok]

I'm also interested to know how well these methods hold up over the years. I've seen excellent results - I just hope there's no problems down the line from doing this.

[emilstorm]

Has anybody tried chlorine on white minifigs with print? I have a lot of those 80's doctors and EMTs that are almost brown now, and it would be a shame to lose the print.

[Boulderer]

Hi,

I'd be interested to know if anyone has noticed any issues with embrittlement of the pieces after exposure to the cleaning agents? I've got a lot of yellowed bricks but, I'd rather them be yellowed and in one piece than white and broken :)

[TheLegoDr]

I have only recently done this, so I can't attest for long term strength. But since a lot of my new bricks break just by attaching to other bricks, I'm not too worried about it. That way they can all match and crumble together...

[Boulderer]

I have only recently done this, so I can't attest for long term strength. But since a lot of my new bricks break just by attaching to other bricks, I'm not too worried about it. That way they can all match and crumble together...

The youth of today! In my day, Lego used to go through hell in the name of play and still be fresh as a daisy

[fred67]

I first used hydrogen peroxide several years ago... it worked great, although for bad pieces I might have to leave it out in the sun for 2 days instead of 1 (I do live in sunny Georgia, USA, the sun is quite strong here).

The last few times I've added the Oxiclean, and get spectacular results in 6 or 7 hours. It never ceases to amaze me.

Note that you don't have to use a retrobright style with a thickening agent - if you have small piece, you can just put them in a plastic container (last time - just a week or so ago - I used a small pick-a-brick container), cover the pieces with hydrogen peroxide (I use the very low % version you find in the supermarket... just don't water it down any more) and a tablespoon or so of oxiclean. Stir it up, leave it out... I did go an stir the parts after a few hours.

It does affect the pieces. I wouldn't say they are dry and brittle, but you do clean ALL the oils off of them - most of your parts probably have the slightest coat of oil just from being touched. It might make them harder to put together and increases the clutch power. Over time, I cannot tell you which were the pieces I de-yellowed, but I've done mostly white and gray with a few blue pieces thrown in.

I will admit most of my pieces immediately just go into their bins, and maybe along the years I've taken them out and built something, maybe not... I mix them in with my other pieces, and can't tell you which ones had been cleaned, so I do not think there's any long term problems. I've never done one with stickers or print on it.

The retrobright formula includes thickeners only so that you can "paint" large pieces with it... so you don't need the thickener unless you're doing something you can't reasonably submerge.

[TheLegoDr]

^To add, I have done a handful of smaller printed tiles. All have come back sparkling white again with no change to the printing (as far as I can tell). I understand being iffy on prints, but I threw caution to the wind and it seemed to work okay. But that's just my experience.

[Jdurg]

For those wondering if the retr0bright treatment will permanently remove the yellowing, the answer is NO. This is the reason why. (Warning! Chemistry discussion!)

Lego parts are made from a type of plastic called ABS which stands for Acrylonitrile Buadiene Styrene. It's a mixture of three different chemical compounds that forms a tightly knit, sturdy, and workable end product. The product, however, is not free from catching on fire and creating problems. Therefore, manufacturers also include a flame retardant in the mixture to stop it from spreading fires. The flame retardant used is generally a brominated compound meaning that it has bromine atoms in there which are readily "dislodged" from the molecule which is what helps it stop fires from spreading.

The problem with bromine is twofold. One problem is that the bromine atom when it attaches to something is generally not very tightly attached. Therefore, when something like a photon of UV light hits the chemical bond, it will break the bond and free the bromine atom. This bromine atom will then attach to something else and not what it was originally attached to. The second problem is that elemental bromine is a nasty, deep brown, volatile liquid. Volatile meaning that it readily vaporizes. The name of the chemical element, bromine, comes from the Greek "Bromos" meaning "stench" as the element smells like a skunk that has taken a bath in bleach. (Not that surprising since, like chlorine, bromine is a halogen).

Anyway, when you have your white or light gray Lego pieces out in the sunlight, the UV rays will interact with the brominated flame retardant in the ABS plastic and "knock" a bromine atom free. If this bromine atom binds to another free bromine atom in the mix it will form elemental bromine. That dark brown, nasty substance I just described. As this bromine is trapped within the tightly bound structure of the ABS plastic, it will sit there and you'll see the discoloration showing up.

What the retr0bright method does is generate a good deal of oxygen gas from the decomposition of the hydrogen peroxide. Under UV light (whether from a UV lamp of the sun), the UV light will break apart that bromine bond and cause the bromine to bind with the free oxygen generated from the peroxide decomposition. At the same time, the heat of the reaction expands the plastic at a molecular level allowing the oxygen atoms to get in there, or unbound bromine atoms to get out. It doesn't need to get deep into the ABS pieces since the breakdown of the flame retardant generally happens on the surface. (As is seen by the fact that parts of pieces not exposed to UV light are generally still close to the original color).

Unlike what many in this thread have stated, this process is NOT "dissolving" away the top layer of plastic on the Lego piece. Any softness that may be noticed is likely due to the heat generated by the chemical process which will of course soften the Lego pieces. In addition, if you leave it in the peroxide solution for too long, the peroxide (especially if it's concentrated) can attack the ABS itself and cause problems. However, if you watch the pieces and take them out as soon as the discoloration is gone, then go and wash and dry the pieces, all will be fine.

Some things to keep in mind:

Do NOT put this solution in a sealed jar while the reaction is happening! This is especially true for the more concentrated peroxide solutions as there will be a LOT of oxygen gas generated. If it's in a sealed container made of glass, you might have a bomb ready to go off. ALWAYS leave the cap on loosely so gas can escape.

You also cannot re-use the solution. As time goes on, the peroxide decomposes and becomes more dilute and therefore less effective. So after one or two uses, you have to throw it out.

ALWAYS wear eye protection and gloves. ESPECIALLY with the more concentrated solutions. You do NOT want this stuff in your eyes as it WILL blind you. You also don't want this on your hands/fingers as it will cause nasty little burns that will take time to heal.

Keep in mind the temperature. You don't want this getting too hot as it will start to damage the pieces and the decomposition of the peroxide increases as the temperature goes up, releasing more heat, etc. etc. Try to keep it as room temperature as you can.

UV light is really key to the process. Any changes you see without UV light are likely caused by the peroxide eating away at the surface of the plastic.

Make sure that the peroxide you use only contains hydrogen peroxide and water. You don't want to use brands that have other chemicals in there (especially true of hair product peroxides) as these are likely to attack the ABS in unexpected ways.

Just my thoughts as a chemist and a Lego fanatic myself who wants to ensure the safety of everybody, the restoration of aged parts, and fun!

[Artanis I]

I have read that before, but thanks for being detailed again. I was just wondering yesterday, if anyone knew of a process to do the reverse! I want to "yellow" some white parts, but in a uniform manner. So I don't want to just put them in the sun, because the colour won't be consistent enough.

I intend to make my own "tan" wargs!

[fred67]

Thanks for the detailed explanation Jdurg, it also helps explain why Oxyclean is such a good catalyst.

[RTZX9R]

I have used oxyclean, hydrogen peroxide and the Florida sunshine and had great results in bringing white bricks back to life.

HOWEVER, I have also run into severe cases where it affects the strength of the bricks and they crack very easily afterwards. I would caution anyone doing this to try a few pieces of low value first before trying it.

[AmperZand]

I'm in the midst of a project to restore a set with quite a few white bricks. Some of the used parts I got from BrickLink were slightly yellowed - enough to make them stand out from new white bricks. So I bathed them in 6% (20 vols) hydrogen peroxide mixed with Vanish Oxi Crystal White in a glass jar in direct sunlight for a few hours and now they're practically white as new.

Some of the pieces were printed and the process doesn't seem to have affected the printing at all.

The only thing is that all the parts now have a slightly different feel. When you rub them, they catch your skin as if they're slightly grippy. I wonder if they look any different under a powerful microscope. Unfortunately, I don't have one to check. To the naked eye, they just look whiter. The shininess of the pieces is the same.

[TheLegoDr]

^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?