Over the years, people have learned to contact me before they discard things like surplus archive boxes, old folders, and giant tubes. I always find a way to work them into a story time project (even if it means cramming them in a storage closet for months, praying they don’t topple on me while I’m trying to wrestle a stubborn pack of sparkle stems from a bin).

But our most recent acquisition was a little was unusual. It wasn’t office supplies or packing material. It was a LEGO set. An ancient Civil War LEGO set unearthed from the History Department’s graduate study room.

The set had collected a considerable amount of dust over the years, and as I pondered its fate, Katie said “You know, I saw some great LEGO cleaning tips on Pinterest. One woman even threw hers in a washing machine!” Really?

I know that many libraries, classrooms, children’s museums, and homes have LEGO and DUPLO sets in them, and that keeping them clean is a concern and a frustration. So we thought it would be helpful to test 3 different cleaning methods on 1 dirty LEGO set and report the results. Katie gamely volunteered. Here is the report, based on her excellent field notes.

TEST #1: WASHING MACHINE

For this method, you’ll need a mesh laundry bag (also knows as a lingerie bag). First, Katie removed all the small bricks and tiny pieces (basically, anything that could fall through the holes of the mesh). Then she pulled the rest of the bricks apart, dropped them in the bag, and wrapped a rubber band around the top for extra security. After reading a number of comments and suggestions on the original Pinterest post, Katie decided to wash the bricks using the delicate cycle, in warm water, on low spin.

Katie’s washing machine is a front-loader. The LEGO set was loud. Super loud. 35 minutes of loud. I asked her if she thought a top-loader would have been quieter, and she said that some of the Pinterest commentators used top-loaders and…it was still super loud.

When the machine stopped, Katie discovered that a small handful of LEGOs had escaped the bag. Not so good. The low spin cycle did dry the bricks a little but they definitely needed air drying.

TEST #2: DISHWASHER

Katie prepped another set of bricks and put them in a mesh laundry bag on the top rack of her dishwasher. After consulting her machine’s operating manual, she decided to use her “china” setting (warm water, no heat dry). She didn’t want the LEGOs to melt on a hot water/high heat cycle. The dishwasher was much, much quieter. However, the no heat dry meant that the LEGOs were super wet and needed considerable air drying time.

TEST #3: HAND WASH

A final set of LEGOs were prepped and placed in a small mixing bowl with warm water and dish soap. IMPORTANT! When washing LEGOs in your sink, make sure you put in the drain plug in place. LEGOs in garbage disposal = bad news. Wash and rinse the LEGOs thoroughly, then drain.

Toting piles of wet LEGOs, Katie headed outside with some towels and spread the pieces out on her back porch. But the humidity was so high, she had to bring them back inside and spread them out on her kitchen floor overnight, which worked great.

AND…THE RESULTS!

There weren’t any discernible difference between the 3 washing methods. Strangely, the white and yellow bricks still held on to a little dirt (and it’s not just because dirt shows up more on light colors, we examined all the bricks very closely). The blue bricks were the champions of cleanliness. Not a speck of dirt to be seen!

Cleaning LEGOs in a washing machine is not recommended. It’s just too loud and some bricks escaped, which could potentially scratch the interior of your machine. The dishwasher is quiet, quick, and does the job. But if you use anything other than warm water, you risk warping or melting your LEGOs. So if you’re going for the full-out disinfecting, a good old fashioned hand wash is the way to go. Especially since you can use hotter water (and disinfect with vinegar or diluted bleach if you choose).

The sparkling clean LEGOs were immediately put to good use by Katie’s son, who spent a busy afternoon enthusiastically building an impressive football/castle/Civil War reenactment/futuristic battlefield.

Want to see what we’ve done with some of our other recyclables? Check out this post!