Washing Lego bricks by the kilo

The setup

Here you are, the proud new owner of ten kg (or pounds) of Lego bricks that you got on bulk on eBay, Craigslist or else:


Those need to be washed, but here comes the obvious question: how?

Well, if you have time and are so inclined to spend it this way, you have the toothbrush method:

Let’s see: the average Lego piece is less than 2g, so 10kg is about 5000 pieces. If you spend 5 seconds per piece with the toothbrush (including grabbing the piece and dropping it), you’re in for 7h of hard work. If you paid the average of $6 per pound or 12 € per kg, these 7h of work (at minimal wage) is going to almost double your cost.

There is a more efficient way!


Put all the Lego in a big plastic bin. Cover generously with dishwashing liquid. Spray with warm water (at about 40°C or 105°F). Move the pieces around. Let soak for 3-4h.



Pour the content of the bin in one of these Ikea laundry basket with a thin mesh (it’s called FYLLEN and can be found here for example). The water will be dark and dirty. Spray some warm water. Rotate the basket on the side. Spray more water. Rotate again. Repeat until most of the dishwashing foam is gone.



Take the basket outside (or anywhere where water can drip) and leave it to dry. Rotate and shake once in a while to make sure the water comes out of every pieces. Leave outside for 1-2 days.



That’s it, it took about 15 min of your time (you can spend the 6h15 you save on sorting those Lego bricks… more on that later). The bricks come out pretty clean and without dust left (including on those hard to reach corners).

Removing permanent marker from Lego minifigures

tl;dr: isopropyl alcohol.

A few weeks ago I got a bunch of badly treated Lego minifigures: quite a few of them were completely colored with permanent marker. The advice you get from dealing with that on the internet vary widely. A popular advice is to use acetone, or the popular equivalent: nail polish remover (acetone is usually the main component). But if you’ve seen the Lego movie, you’ll be well aware that using the secret weapon Po’lish Remover of Na’il on your precious minifigures is a risky business (you’ll be left with monochrome plastic, loosing all the patterns). Don’t do it:

Lego bricks are made of ABS (or Acrylonitrile butadiene styrene) which is soluble in acetone. Basically, it’ll just melt your lego bricks.

Another interesting advice is to use a toothbruth and toothpaste and brush for 10 minutes, that’s a lot of work and the result is not great:

One thing that works pretty well is isopropyl alcohol, I used the 90% one that you can easily find in any pharmacy. Just soak a Q-tip in it, wipe the minifig. Depending on the amount of permanent marker, you might need several Q-tip. Once you’re done, rinse the minifig in water. Basically, is comes down to:

  • Pour a bit of isopropyl alcohol in a bowl
  • Soak the Q-tip in the alcohol
  • Rub the lego piece with the Q-tip, rotating it to take the marker away
  • One the Q-tip is fully soaked with marker change it
  • Repeat
  • Throw the lego piece in a bowl of water
  • Dry

It’s a good idea to use gloves and to do that in a well ventilated room (or better, outside).

Here are some examples

Before After
1_b 1_a
2_b 2_a
3_b 3_a
 4_b 4_a

Not too bad for the bodies. It’s much harder for non flat surfaces and scratches. But as you can see, the original pattern on the minifigs are not damaged.