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Brick Discoloration Due to Sunlight/Smoking and Methods to Restore

EricEric Member Posts: 376
edited February 2014 in Collecting
I have come into some old Classic Space and Futuron sets from the 80's, mostly complete too. :) But most of the white, grey and some of the blue pieces, (which is just about all of the pieces), have discoloured horribly. I suspect nicotine or direct, direct sunlight to be the culprit, as the larger wing sections are very, very yellow. Even some of the minifig's faces are discoloured where they faces are seen through the helmets!

Any tips on cleaning/restoring some what, to at least good enough that I can display them? I read that Hydrogen Peroxide works wonders, but is this just regular household bleach? Or is there some special plastic cleaning bleach that works better?

Has anyone had any success in getting these stains off?



  • allyburnsallyburns Member Posts: 62
    I have purchased two bottles of Hydrogen Peroxide from the chemist, along with some OxyClean powder.

    I have not yet attempted to restore them, but am going to use these urls as my guide:

    I'll probably do some more googling too! When I do finally try it, I'll be sure to post the steps I took and photos of the before and after. In my head I think it'll never work, but from reading the forums, it sounds like miracles are possible!

    I too am interested in hearing from anyone who has actually done it successfully - what were the exact steps they took - equipment, timings etc. I'm in Scotland so dont have ready access to sunlight :o)


  • drdavewatforddrdavewatford Administrator Posts: 6,754
    edited April 2011
    ^^ Be careful - my experience of this technique is less than optimal :

    I think a much more systematic exploration (different types of U.V. source, different durations of exposure, before and after pics, different concentrations of hydrogen peroxide, different catalysts) would certainly be of value, rather than my unscientific "bucket chemistry" approach....
  • paul88paul88 Member Posts: 169
    Hi Guys,
    I have extensive experience with this process. I've done old RC car parts, as well as Lego bricks. Here is what you do... you need regular hydrogen peroxide (30%), glass jars, and sunlight.

    Fully submerse the pieces, put them in the glass jars and then put the jar in bright sunlight. About every hour, stir them around. Depending on how extensive the yellowing is you may see results in as little as hours, or it may take a few days.

    Do NOT use bleach! Bleach will break down the bricks on a molecular level and cause them to be brittle. Also, do NOT put decorated bricks in the peroxide. I have had mixed results but can tell you for sure that it WILL strip the gold off of old space bricks.

    I haven't checked the links posted above, but imagine they instruct along the same lines that I did in this post.
  • MatthewMatthew Administrator Posts: 3,714
    ^ Where do you get 30% hydrogen peroxcide from? Not that I've looked, but @drdavewatford said the highest he could find was 9%
  • paul88paul88 Member Posts: 169
    Oh man, I'm SORRY!!! yeah some "extensive experience"... I mis-typed, it should have been "3%" not "30%".... I think 3% is that standard that you get at walmart or similar stores.
  • EricEric Member Posts: 376
    Where would I find it in the store? Under the Laundry/Cleaning Section? Or the Medicinal Section?
  • paul88paul88 Member Posts: 169
    It's usually in the medicine section where you would find bandages and rubbing alcohol.
  • EricEric Member Posts: 376
    Got some, will give it a go and let you know.
  • MinifigsMeMinifigsMe Member Posts: 2,844
    You can get 30% - it's in the hair dye section - for bleaching hair.
    About £1.50 in boots - you could dilute this 1:10

    I'm going to give this a go with some random old white and blue bricks, with 3, 5 and 30% and see what happens.
    I'll keep you posted.
  • brickmaticbrickmatic Member Posts: 1,071
    ^ If you're doing an experiment, I'd also add duration of exposure as a test variable. Are you planning on using catalyst?
  • paul88paul88 Member Posts: 169
    Absolute best is to make sure you have plenty of sunlight!!! The peroxide alone will not work. I have experimented with old transformer parts, rc car parts and lego. I've heard of people using blacklights where sunlight is not available. I have tried this but it is a MUCH slower process.... one day in the real sun would probably be equal to 3 or 4 days under a blacklight.

    Another trick is to put aluminum foil behind/around the side of the jar that is not facing the sun (if, for instance, you have it on a window sill). I've had very good results with everything I've tried, but it takes sunlight and TIME. Change out the peroxide if you keep the parts in more than 5 or 6 days.

    I would hesitate to use anything stronger than 3% again that is 3%. SOme transformer collectors noted that the 30% was too strong and could actually damage the plastic.
  • MinifigsMeMinifigsMe Member Posts: 2,844
    I plan on doing a fully controlled scientific experiment with this :-) I am a scientist after all. I might try adding some KCl as well. Duration is easy to adjust, I'll just fish 'em out and check them against new and un-cleaned bricks.
    I wouldn't be surprised if 30% is too strong and makes them brittle - look at what it does to my hair!!! ;-)
  • brickmaticbrickmatic Member Posts: 1,071
    ^ KCl, as in potassium chloride? Do this act as a chlorine bleaching agent? If so that should make the bricks brittle. Allegedly chlorine replaces bromine in the plastic.
  • MinifigsMeMinifigsMe Member Posts: 2,844
    edited April 2011
    Hmm, you could be right. I'm a biologist not a chemist. We use H2O2 and KCl to bleach pigment in organic tissues. I'll ask a chemist friend if he knows better, and raid the shelf at work for more options.
  • davee123davee123 Member Posts: 852
    @lukehankenobi from the other thread:

    (BTW, the other thread has to do with non-treated bricks, this thread has to do with the chemically treated bricks)
    Put UV damaged Lego back in the Sun.
    If anyone can explain why this works I would be very interested! How can the same thing that caused the problem, cure it?
    This works with varying degrees of success.

    As I understand it (and I'm no chemist!), there's a flame retardant in LEGO that contains Bromine. When UV light hits the flame retardant, it has the ability to break the chemical bonds. Under the right circumstances, Bromine atoms bond to other Bromine atoms, forming Br2, which is sort of yellowy-brown. If this happens too much, the yellowy-brown color becomes more pronounced, and your bricks look ugly.

    However, (again, as I understand it) UV light ALSO has the ability to break down Br2 molecules. Again, under the right circumstances, the loose Bromine atoms can re-bond properly in place rather than in Br2.

    That means basically that depending on the particular batch of ABS that you have, the particular color, the strength and directness of the UV light, and other conditions (ambient heat, moisture, pressure, whatever), UV light can be either repair or destroy the color of your bricks.

    Using the chemical treatment (like Retr0brite), I believe the randomness is reduced, forcing the loose Bromine atoms to prefer their initial state (bonded to the flame retardant) rather than being bonded to other Bromine atoms.

    But that's my non-expert-uninformed understanding. Hopefully someone with a better understanding of chemistry can provide a better answer.

  • MinifigsMeMinifigsMe Member Posts: 2,844
    I forgot to update this, I made a mistake and KOH is what we use for bleaching pigment in organic tissue. I tried 3% h2O2 alone and 3% h2o2 and 0.5% KOH in the sun for 2-3 days. The KOH speeded things up and the whites have come up great, so much so that they're putting some of my dirtier 'new' whites to shame. The blues weren't really affected much, there's so much variation in the shades of blue I've got I'm not sure this process will help.
  • lukehankenobilukehankenobi Member Posts: 6
    @Davee123 - Thanks, and you seem to have a pretty good understanding actually. So in a way you don't get rid of the yellowing at all, you just re-convert the Br2 back to it's initial state. I am finding good results (so far) without the use of chemicals, though newer pieces work best. In the window or in the Greenhouse.
  • EricEric Member Posts: 376
    Agree with Savage_Steel, the whites came up brilliant, and only my really off colour blues were affected. Great stuff.
  • brickmaticbrickmatic Member Posts: 1,071

    "However, (again, as I understand it) UV light ALSO has the ability to break down Br2 molecules. Again, under the right circumstances, the loose Bromine atoms can re-bond properly in place rather than in Br2."

    Not quite. I believe bromine bonds with oxygen in the air. The idea is not for the bromine to re-bond to the flame retardant from which it originated, but to bond with hydrogen so that it is not an ugly yellow color.

    UV light is simply an energy source. If you recall activation energy from chemistry class, most chemical reactions need the addition of energy to get going. A piece of paper will not spontaneously burn. You need to add energy by heating it up. Once a certain threshold is passed, it goes downhill and releases energy. The paper burns and turns to ash. However, this only happens if there is oxygen present! If you heat up paper in an environment without oxygen then it will not burn. That's the idea behind UV exposure with ABS plastic. UV light energizes the bromine atoms allowing various chemical reaction can happen. In an oxygen rich environment, like the air, this reaction results in oxygen attaching to the bromine. In hydrogen peroxide, a hydrogen rich environment, this reaction results in hydrogen attaching itself to the bromine. You want hydrogen because it doesn't make something that is ugly yellow like the oxygen does.
  • oldtodd33oldtodd33 Member Posts: 2,683
    Well, I can absolutely say that putting several 12v straight tracks in hydrogen peroxide for 2 hours in the sun works like a charm. They were very yellow and are now like new again. I can also tell you that a Dremel rotory tool with a steel brush takes rust off of them very well, it leaves a dull finish but I should be able to polish that out.
  • StuBoyStuBoy Member Posts: 623
    ^^ Good, simple explanation! I'm going to try this at some stage, might wait until spring or summer. Is there a danger of over-exposing the bricks to UV? Do you need to visually monitor the progress and remove when yellowing is gone, or just keep them in the sun for as long as possible?
  • brickbusterbrickbuster Member Posts: 6
    Ok I've had success with a diluited peroxide solution in glass jars in the sun. I put my yellowish white, blue and transclear old lego from the 80's in the jars in a good sunny position over the space of two days periodically shaking the elements in the jars.These photos aren't the best but the the results were a vast improvement on most of the elements. some needed another go, I'm guessing due to the limited exposure due to competing with the other lego.I havn't seen any weakening or brittleness in these elements. I guess time will tell.I am in Australia and tested in the winter sun. imageimageimageimage
  • brickbusterbrickbuster Member Posts: 6
    sorry about the pics. uploading is not my strong suit
  • madforLEGOmadforLEGO Member Posts: 10,761
    Looks like some parts had more success than others
  • MinifigsMeMinifigsMe Member Posts: 2,844
    I've had great experiences with bring whites back from the yellow side, but has anyone done this with Yellow bricks?

    I've just built "build a bob" and just a handful of the yellow pieces are a different yellow. I'm not sure if it's discolouration or if some older/newer pieces have crept in. (it was in a bulk buy and mostly constructed, and I'm too lazy to deconstruct it, as I was just checking it for re-sale)

    Also, how's H202 on bley and dark bley?
  • oldtodd33oldtodd33 Member Posts: 2,683
    @StuBoy With the old light grey you can be flexible with the soak times. Old dark grey is not very tolerant of being set out too long. I use a standard glass baking pan filled to the level I need to cover the parts. I check the dark grey every 15 minutes but I am at 6000 ft. plus so yours will most likely take longer. I have left the old light grey out for up to 2 hours and they seem fine but you should always soak parts that are going into the same model at once so the colors match the best. You will also have to check the parts often because with the way I do it the peroxide causes bubbles underneath the parts and causes them to float to the surface. It is kind of a pain but well worth it to save the old parts.
  • StuBoyStuBoy Member Posts: 623
    @oldtodd33 Hmmm... sounds like I need to sort my greys out depending on level of yellowing, as some are more yellowed than others, and going by your description I'll need to have them soaking for longer than not so yellowed bricks.
  • kufkuf Member Posts: 66
    What printed pieces survive through the H2O2 process okay? Does the printing on horses survive, for example? Do certain printed colors survive better than others?

    Also, what happens to pieces if they are in the H2O2 process too long?
  • EricEric Member Posts: 376
    I can't say what will happen to prints, but I left some very bad parts out in the sun for about a week and they came out fine.
  • y2joshy2josh Member Posts: 1,996
    I have a single Scout Trooper from the old Speeder Bikes (7128) set that has yellowed horribly badly, and I'm not at all sure why. The helmet is still bright white, but the entire torso looks like it's been smoked on for years (and this is after being stored in a smoke-free home since purchase). I realize the figure is some 13 years old at this point, but the other Scout Trooper from that set still looks perfect, as do all my Stormtroopers and Snowtroopers that are nearly as old.

    That's neither here nor there, though. I, too, am interested in knowing if a printed piece will survive the de-yellowing process. If not, I'll pick up an extra troop builder to replace this piece with, but I'd prefer to just salvage the one I have.
  • LeelaLeela Member Posts: 53
    I put my printed Pirates flags into a mixture of H2O2 and Vanish :) and kept it in sunlight for hours and it worked wonders. Nothing happened to the print but I'm still cautious when it comes to printed parts.
  • kufkuf Member Posts: 66
    My printed pieces are coming out fine. I'm not having much luch with non-whit pieces however. The pieces are coming out matte instead of glossy. They look ok when they are in the H2O2, but when I wash them off and they dry they lose shine and whiten.
    Are they just in too long? Are they just too far gone? Is there anything I can do to get some shine back? The pieces look good when wet!
  • LegoboyLegoboy Member Posts: 8,825
    ^ Perhaps you could use them to moc a submarine?? :o)
  • oldtodd33oldtodd33 Member Posts: 2,683
    I don't know about the matte look. But they will whiten if you leave them in too long. Blue bricks take the longest to come back but old light grey and white usually do well if not left in too long.
  • IstokgIstokg Member Posts: 2,362
    @brickbuster - Those 4x8 curved plates are not made of ABS plastic... they are made out of some other type of plastic (TLG never said).... so your results from trying to whiten those will likely be different. Those early plates were never shiny to begin with, and always had a matte finish.

    Also, ironically Cellulose Acetate, the plastic that ABS replaced in 1963, has a tendency to not lose its' whiteness... but had the unfortunate side effect of warping (over long periods of time). So some of you will find white classic windows/doors that have stayed a very pure shade of white. And that is due to them NOT being made of ABS plastic... and apparently not affected by discoloration.
  • IstokgIstokg Member Posts: 2,362
    Also... recently I mentioned that I had an answer to discoloured classic windows and doors that were beyond redemption (as can be found in my USA Bricklink store... Gary Istok Rare Bricks).... ;-)
  • EricEric Member Posts: 376
    edited February 2012
    ^ Just normal spray paint? What's the finish like? Looks alright from the picture.

  • IstokgIstokg Member Posts: 2,362
    It depends on which one you use... high quality modeling spray paint in a sort of matte finish works best...
  • DeadareusDeadareus Member Posts: 264
    I've read on a sneaker forum about the yellow reversing effect of a product called Island Girl Sea Glow. It's mostly used for boating applications but people are bringing back yellowing parts of sneakers to white again with this product. Could work for LEGO as well perhaps?

    "Island Girl Sea Glow
    A cleaner and conditioner similar to Crystal Clear, except it has the added property of dramatically improving white and other bright colors of gel coat and vinyl. It converts UV to visible light with almost startling effects. Both Crystal Clear and Sea Glow restore flexibility to old vinyl. Sea Glow is also effective in keeping sneakers looking like new and white. Simply spray on and wipe off, works on contact. Use a soft bristled brush for heavily soiled areas. An excellent sneaker cleaner/whitener."
  • BrickarmorBrickarmor Member Posts: 1,258
    Is it possible to preemptively ward off yellowing? I ask because I just built the large Discovery Space Shuttle. The previous owner did a commendable job of keeping it clean: for a set nearly 10 years old it was remarkably gunk-free. But I still want to douse the white pieces in a peroxide mix before they get any more tinged. Would this be a waste of time? I'll probably do it anyway...

    and by the way, i was able to get the STAMPs off intact and onto a label sheet for later use!!
  • BrickarmorBrickarmor Member Posts: 1,258
    I guess I should clarify: the white pieces are now only slightly tinged, and I was wondering if a peroxide bath would delay full-scale yellowing by a few years. I realized that my above message kinda made it sound like I thought already white pieces would STAY white with a "protective" layer of peroxide...
  • StuBoyStuBoy Member Posts: 623
    ^ Maybe one of the members with a bit of scientific knowledge like @Savage_Steel or @brickmatic would be able to give some good advice on this.
  • MinifigsMeMinifigsMe Member Posts: 2,844
    Sorry, my science is limited to genetically modified stuff! I have access to lots of chemicals, but most I don't know what they do!
    I do wonder if that Sea Glow stuff would offer some protection from it's description?
  • brickmaticbrickmatic Member Posts: 1,071
    @Brickarmor Yes, there is a way to preemptively ward off yellowing. Namely, keep it away from UV light. This could be a protective UV clear coat or just keeping it in a darkened space. An alternative strategy would be to take away the oxygen. Not sure how practical this would be.

    One note, @LEGO_Nabii mentioned there could be issues keeping bricks in the dark.
    As others have said direct ultra violet light -sunlight- can cause rapid yellowing, but so can darkness. The plastic is as ordered stable under normal conditions for a toy, this includes a day night cycle. According to LEGO quality control too much dark is as bad for some of the secret formulas of the chemical companies as direct sunlight is for others.
    That said, I'm skeptical because I'm not quite sure what the mechanism is for that. I suspect that yellowing in storage can occur from other oxidation processes. Basically, in an oxygen environment oxidation will eventually occur. UV light accelerates the effect.

    Here is another article about ABS yellowing that I don't think was posted before (might be wrong):

    @Deadareus I would not use a product designed to restore boats to process LEGO bricks. First of all, the treatment is designed for use with polyvinylchloride (PVC), polyester, and chlorosulfonated polyethylene. It is not designed for use with ABS. Second, the treatment works by removing the oxidized surface layer, something I wouldn't want to do to LEGO bricks. Thirds, the product contains plasticizers to condition your plastic, but not necessarily ABS plastic. From the "Handbook of Plasticizers" by George Wypych:
    When ABS is contacted with other materials that contain plasticizers {e.g. PVC} stress cracking may occur. Time to break and the force required have been drastically reduced when ABS was contacted with nineteen samples of PVC each containing different plasticizers. This shows the performance of ABS will depend on the type and amount of other materials in the formulation.
    Not saying your bricks would break, but rather that the material properties of your bricks would most likely change. And finally, I would be concerned about the type of chemicals I would be putting on my bricks.
  • yys4uyys4u Member Posts: 1,093
    edited April 2012
    Been searching this topic recently. Wondering if there's any updates to peoples methods? Exposure time, amount of Hydrogen Peroxide, success with every day supplies, not lab quality chemicals :)

    And before and after pics?
  • RedbullgivesuwindRedbullgivesuwind Member Posts: 2,108
    I have three yellow old bricks that im not to sad to lose so. When i have some spare time what ill do is set up a big experiment.

    They are badly yellowed so I can put one in the standard peroxide at the normal strength. one in tap water and one using a whitener from above. then see
  • greekmickgreekmick Member Posts: 710
    I actually purchased a bottle of hydrogen peroxide yesterday to try this out on a batch of bricks I picked up at the boot sale. I will wait for some sun and let you know how it goes.
  • littletokilittletoki Member Posts: 519
    Great results with hydrogen peroxide - super easy.

    Soaking in the sun:

    Hydrogen Peroxide bath


    Hydrogen Peroxide: Before and After

    You'll have to be more hands on with colors - if they stay in too long, they take on a white, cloudy appearance. Like those blue wedges in the glass pan - they looked pretty good after 6 hours but I was greedy and wanted all the yellow out. So I soaked them for another 12+ hours and now they look cloudy in spots.

    I also had plain yellow bricks in for 20+ hours and they came out fine so it depends on the colors.
  • SirBenSirBen Member Posts: 592
    @littletoki What concentration is the hydrogen peroxide that you used? Is it the standard 3% first aid kind, or one of the stronger solutions sold for hair coloring/highlighting?
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