LEGO that's been played with for years can get grubby — dust, sticky fingerprints, the odd bit of who-knows-what. A quick clean before you sell can nudge the value up, because clean bricks are worth more than dirty ones. Here's how to do it safely.
The simple, safe method
- Hand-wash in lukewarm water with a little mild washing-up liquid. Lukewarm is key — hot water can warp or discolour bricks.
- Soak briefly, then gently agitate. For stubborn grime, a soft toothbrush works well.
- Rinse in clean water.
- Air-dry thoroughly on a towel, spread out, for a day or so. Make sure they're completely dry before bagging — trapped moisture causes mould and cloudiness.
What NOT to do
- No dishwasher — the heat and harsh detergent can warp, fade and dull the bricks.
- No hot water — same warping risk.
- No bleach or harsh chemicals — they damage the plastic and finish.
- Don't submerge electronic parts (motors, light bricks, battery boxes) — wipe these with a damp cloth instead.
Minifigures and printed pieces
Be gentle with anything printed (faces, torsos, decorated bricks). Scrubbing hard can rub the print off, which lowers value. A soft wipe is enough.
Don't overdo it
If you've got a giant tub of loose bricks being sold by weight, you don't need to wash every single piece — just pick out anything obviously grubby and give the worst of it a clean. The aim is "presentable," not "showroom."