Brick de-yellowing techniques

[Sting]

Okay, I know that cigarette smoke and sunlight cause yellowing...

For sunlight, is it DIRECT sunlight, as in, Beams shining onto the Lego for prolonged periods of time. Or if a room, lit technically by sunlight during the day (no direct light shining in the room or onto the lego), will that cause yellowing?

[Starwars4J]

Direct sunlight will make the bricks yellow faster, but even casual exposure to natural light over a prolonged period of time will cause them to yellow. Nothing lasts forever, so don't worry about it. You can't exactly lock yourself in a room and ONLY have your lego there, now can you? Where's the fun in that?

[Sting]

I'm sure most Lego fans could have fun in a room with just lego LOL. Lego and some Chips (or crisps for the British :) ) in a room. That would be good. LOL.

But I understand what you mean. I am not sure what to do than. I guess I just cannot keep my lego displayed in my room too long, as I dont want my entire collection of white going bad :'-(

[snefroe]

i wouldn't dramatise, really. just keep it out of the sun...

[Starwars4J]

Well, that's why I said prolonged ;-) Nothing is going to happen on a timescale you will notice.

[natelite]

i recently got a very old box of lego from my parents (from my childhood). some pieces did not age at all. others have yellowed so much. they are on the same minifig too. i'm not quite sure what causes it since if it was purely sunlight i'm sure the entire figure would have yellowed. i have a space police buggy, and only one piece in the prison transporter yellowed but the rest were still okay. it's quite puzzling for me to be honest.

i'm speculating here but i think the yellowing may have been caused by oily hands or sweaty palms and exposure to sunlight. we all know if white t-shirts aren't washed properly, it will yellow over time even if you kept it in a dark closet. i think to preserve your lego, if you are going to store it for a while, to wash it clean first before leaving it in an encased display unit.

[Lego Amaryl]

Yes, not all white bricks yellow. I have seen hospitals with some bricks that have become tannish, and other bricks still white. In the same set, exposed to the same light during the years...

[Bonaparte]

I try to keep my lego room as dark as possible.

When nobody is in there, it is 100% dark!

I did read of a technique on how to make white pieces that yellowed again white.

I think it was with bleach water...

Don't remember where that was mentioned |-/

[Norro]

...but even casual exposure to natural light over a prolonged period of time will cause them to yellow. Nothing lasts forever, so don't worry about it.

Begins nailing boards over windows and ordering a 'de-pressurizing kit' from the back of popular mechanics... X-D

God Bless,

Nathan

[Minifig Lecturer]

The easy solution is to play with your lego whilst wearing night-vision goggles.

[Sting]

The easy solution is to play with your lego whilst wearing night-vision goggles.

Lol! Sold!

[Capn Frank]

The easy solution is to play with your lego whilst wearing night-vision goggles.

you know of a good brand of night vision goggles by chance?

I try to keep my lego room as dark as possible.

When nobody is in there, it is 100% dark!

I did read of a technique on how to make white pieces that yellowed again white.

I think it was with bleach water...

Don't remember where that was mentioned |-/

My lego room has one small window. it's on the north side of the house. but i think i'll cover it up to help prevent yellowing

hmm, i wonder if bleach water would work. That'd be flippin sweet! I've got a lot of pale yellow bricks (white).

[snefroe]

I try to keep my lego room as dark as possible.

When nobody is in there, it is 100% dark!

I did read of a technique on how to make white pieces that yellowed again white.

I think it was with bleach water...

Don't remember where that was mentioned |-/

we do have a topic about that, sure... ;-)

the main thing is that it seems bleach is NOT good for your bricks after all

[Bonaparte]

we do have a topic about that, sure... ;-)

the main thing is that it seems bleach is NOT good for your bricks after all

From what I can remember, the bleach only worked for bricks that were originally white.

It was not suited for other colors.

But on CC I found an interesting experiment using Hydrogen Peroxide:

Day #1

An assortment of discolored "classic" light grey and white bricks, saving some of similar discoloration out as a control. The picture on the upper left is with a flash, the other without. Here you can see some of the white bricks are badly discolored. The light grey bricks have roughly the same amount of discoloration and are about the same color.

(Day #25)

The containment unit. Hydrogen Peroxide is basically made up of water molecules with an extra oxygen atom. Because of this, it is relatively unstable, reacting to both air and water, and gives its free oxygen atom up easily. To counteract this, I stored the bricks and peroxide in an air tight container in an unused cabinet.

Day #25

*obligatory 'whoosh' noise as the containment vessel opens*

Day #25 - White Bricks

Here you can see the white bricks that were soaked lying on a new white baseplate, along with one of the control white bricks. The white bricks were not totally whitened 100%, but they were considerablly better in color than the control.

I theorize a few more weeks and they would whiten further.

Day #25 - Light Grey Bricks

I'm not sure what to make of this. On top you can see the control Light Grey brick, and on the bottom you can see a new Light Grey brick.

Inbetween it looks almost as if there are two Very Light Grey colored bricks and one "New" or "Bley" Light Grey Brick. Had they all turned lighter, I would have surmised that their color had been bleached out. As it is, I have no idea what to think.

[Bonaparte]

Since I'm sorting all my bricks, I discovered a lot of my original white bricks are yellowed.

There's a thread discussing de-yellowing using bleach and one using Hydrogen Peroxide.

However, for my experiment I'm using chloor (NatriumHypochloriet) with is a strong anti-oxidant.

And since yellowing of Lego is caused by oxidization (photodegradation) of the plastic, this seems like a useful experiment to do.

--> Try this at your own risk! NatriumHypochloriet is a dangerous product !!!

This experiment started today (18/11 - 4pm):

Two very yellowed wings from my old airplane will be used

One goes into the chloor, the other stays out and will be use to compare afterwards.

I'll post updates with the result.

Day 2 (after 24 hours):

I switched to another fluid after 4 hours because I was uncertain what effect the NatriumHypochloriet would have on the Lego.

I'll try again later with NatriumHypochloriet on a less important part than my airplane wings.

Now I'm using this: :-D

And here is a first result after 24 hours of de-yellowing:

This is going in the right direction!

Day 19:

This is certainly taking a long time. Here's an update after 19 days.

[Richard James]

What you are using is industrial grade sodium hypochlorite solution also known as bleach - the stuff sold for domestic use is simply diluted. It should be handled with care since it is not only corrosive but also gives off chlorine gas. It shoould only be used in a wellventilated space, you should wear gloves and eye protection at the very least, avoid inhaling the vapours and do NOT let it come into contact with any form of acid. Oh, and far from being an anti-oxidant it is in fact a very powerful oxidiser.

[Stauder]

What you are using is industrial grade sodium hypochlorite solution also known as bleach - the stuff sold for domestic use is simply diluted. It should be handled with care since it is not only corrosive but also gives off chlorine gas. It shoould only be used in a wellventilated space, you should wear gloves and eye protection at the very least, avoid inhaling the vapours and do NOT let it come into contact with any form of acid. Oh, and far from being an anti-oxidant it is in fact a very powerful oxidiser.

Hmmm.. I"d pay to see Boneparte"s Face after Reading that... 8-

[Bonaparte]

What you are using is industrial grade sodium hypochlorite solution also known as bleach - the stuff sold for domestic use is simply diluted. It should be handled with care since it is not only corrosive but also gives off chlorine gas. It shoould only be used in a wellventilated space, you should wear gloves and eye protection at the very least, avoid inhaling the vapours and do NOT let it come into contact with any form of acid. Oh, and far from being an anti-oxidant it is in fact a very powerful oxidiser.

I should have studied chemistry :-D

Do you think this will make the Lego white?

[UniqueBuilder]

Richard beat me to it; sodium hypochlorite is the same as bleach, just more concentrated. :-$

I should have studied chemistry :-D

Do you think this will make the Lego white?

Yes! It is bleach after all. :-P And I can't stress that enough; do NOT let it come in contact with acids! :'-(

[Derek]

I cannot believe how yellow those pieces got! 8-

[alex54]

I cannot believe how yellow those pieces got! 8-

[Lord Of Pies]

Sun! Just let your bricks undr your winows for months and tadaaa! I've got some same colored pieces... :'-(

Me too!

And are you saying I should stop drinking bleach? 8-

[Bonaparte]

I cannot believe how yellow those pieces got! 8-

[john cleese]

how much sun is required to discolour them? My collection is in clear ziplocs in my dads loft, which has two mindows but very little sun gets in through one because of the surrounding buildings. The other window is at the opposite end of the room. Are my peices safe?

[Jipay]

Next step shall be an acid solution...