Second hand LEGO has its risks, cleaning, sorting and quality control checking can be a real chore.

I am very proud of the quality of my second hand products. Thought best to share how I process my LEGO™.

How to clean USED LEGO in bulk or small batches of LEGO.

Firstly be very very careful when you have purchased used LEGO™ in bulk, as some people do not really care what is in that old box. In the worst cases I have found old mouldy food, what could only be described as dried faeces and needles. But mostly I have found that the boxes contain marbles, heavy metal toys and other random non-lego things. Then there is the inevitable non-lego or lego-comtabitble parts. This and the cleaning is what will consume time.

Step One – Cleaning the LEGO


  • A small sharp knife or cutting blade
  • Plastic/latex gloves
  • Scrubbing brushes in multiple sizes
  • A large container that has some sort of draining (A pot steamer works well)
  • Bleach
  • Pillow cases or other material bags.

I used to sort the LEGO first, but I found that most used bulk LEGO is very very dirty and it ended up a real mess. So now I clean the LEGO first and sort later. Dilute the bleach in water and fill up your container with water and bleach. Put your plastic gloves on and sift through the used LEGO, removing any non-LEGO items and also broken items. Separate ALL the pieces, as this is the only way to ensure that each piece has been sanitised. Any really stubborn dirt scrape off with a knife or blade. Once your container is full, I find that a full 24 hour soak in the bleach is best, stirring as often as you can to separate the dirt and let it float to the bottom of your draining container (Which is why a pot steamer works well). Once you can see the LEGO is looking shinny again, then move on to the next step.

Step Two – Drying the LEGO

Pull your LEGO out of the container and pour into your material bag, pillow cases work well. Leave the LEGO hanging somewhere like a garage where the drip of the bleach water will not effect any carpets etc. I leave it hanging there for a couple of days. Then put the material bag in the airing cupboard when speeds up the drying (You can do this first, but the dripping of the bag will make a mess). Once the LEGO is bone dry move on to the next step

Step Three – Sorting and Quality Control of the LEGO

Now that you have a batch of clean, sanitised LEGO, time to get sorting. You will need some plastic bags or small plastic containers to help you. Sorting methods can vary, and really it’s up to you. I sort by colour and part, but that’s how I tend to prepare my items for sale. Sometimes I will collect big batches and evenly distribute them for sale in kilogram batches, but either way sorting has to be done. This is a really good time to look at each piece and see how damaged or broken they are. Also a good time to spot LEGO compatible pieces. Sometimes this can be a real challenge as some manufacturers make parts that look identical. Tell tale signs would be the LEGO text on the studs and almost all genuine LEGO has part numbers. This stage will sift out items that also need a good additional cleaning step. Sometimes LEGO has stickers, sticky tape or marker pens on each piece. You will need to scrub these off. Put them aside and do them later. Put them back into the step one after they are scrubbed clean to ensure that are sanitised.

And thats it, your LEGO is ready to play with.

Play safe, remember that LEGO is a fantastic toy, but not without risks. Ensure you play with your child and do not let them put LEGO anywhere near their mouths.