(Written by William)
Have you ever built a LEGO creation only to scowl down at the few pieces that were discolored? Or have you avoided picking up used LEGO bricks for similar reasons? Given enough time, LEGO bricks can show the signs of aging. Sure, we may have grown out of using our teeth to remove parts, but dirt and discoloration can still add up.

I was having this very conversation with a fellow member of my LEGO User Group. The member in question has a vast collection of old bricks and he rarely buys anything new. However, none of his pieces look bad. They are just as bright and clean as the latest sets to hit the store shelves. Turns out, he has a method to clean LEGO that he swears by. So, since I have a lot of time on my hands these days, I gave it a shot.
LEGO PIECES I CHOSE FOR RESTORING
When I had the conversation about reconditioning LEGO pieces, we were specifically talking about age-related discoloring. The biggest culprit for me has always been white. Though I have found other colors to change with time as well. Thus, for my first experiment, I wanted to restore my discolored white pieces.

The other issue I have to deal with is dirty bricks. You know, that layer of filth that finds its way and clings to pieces. You can use dish soap to remove the dirt, but then the parts creak and crackle. This is in part due to that layer of solution that is used to keep the brick from sticking to the molds. So, I threw those bricks into the mix as well to see if the method I learned about will do anything for that (see before picture above).

Turns out, after a couple of hours of using the method, both the discoloration and the dirt were cleaned off the parts (see after picture above). Additionally, I found that the pieces didn’t show signs of that creaking noise as they do when using dish soap. Needless to say, I went from potentially throwing away old LEGO to fully restoring them!
RESTORING LEGO WITH HYDROGEN PEROXIDE
There are two key elements for this procedure. First, you’ll need enough hydrogen peroxide to submerge the pieces you wish to recondition. Second, you will need a container that can hold the parts and peroxide and allow sunlight in. And that’s it!
The before and after photos I have included here are parts that were left for roughly two hours. However, my friend did say if you have parts that are really bad, it is just a matter of leaving them for more hours. Just remember to check on their progress.
One thing my friend stressed was that the sunlight was essential for this to work. So, in order to be thorough, I tested this out. I found a number of discolored parts and left them overnight in the peroxide inside my house, away from direct sunlight. Turns out, in the morning, they were still discolored. So, I put those same parts out in the sun and checked them around the two-hour mark. Sure enough, the sunlight restored the parts back to their original color. To be clear, I placed the tub of parts outside in direct sunlight. There was no window in the way of the sun’s light hitting the pieces. And I did go outside on occasion to move the parts around so they were evenly exposed.
The nice thing about this method is that it’s easy and relatively cheap to do. I got a small bottle of hydrogen peroxide from a local dollar store, as I didn’t have too many parts that needed restoring. But this process can easily scale up. My friend buys hydrogen peroxide in gallon jugs when he finds them in surplus sale. And he uses a small wading pool so that he can treat a large amount of parts all at the same time.
RESTORING LEGO – REMEMBER SAFETY
The peroxide should disinfect any parts you have, but I’d also recommend keeping your vats of chemicals away from pets and small children. I have roaming critters in my backyard from time to time, so I placed my tub on top of our green waste garbage can. It’s not a surefire way to keep it away from a determined beastie, but it makes it awkward for them to reach the tub. And I just monitored the container regularly to make sure birds didn’t think it was some new-fangled bird bath.
Another point that is worth mentioning is that I did not try this process on printed elements. I’m uncertain how the peroxide would interact with paint on elements or stickered pieces. I’m fairly certain though, if you picked up engraved bricks from a third party, they should be fine provided no special inks were used.
Overall, it was a simple process to do and rather affordable. I even used a funnel to pour all the hydrogen peroxide I used back in its bottle, since multiple uses seemed to be perfectly fine for the solution. This will allow me to stretch that one dollar even farther. So, if you have some reall old ugly parts you just can’t bring yourself to throw away or use, give this a try and bring them back to life! If you would like to learn more about the method, JANGBRiCKS demonstrates it in the following video.
What do you think? Have you used the hydrogen peroxide method before to restore discolored and dirty LEGO parts? Or what other method do you use? Feel free to share and discuss in the comment section below!
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