One of the most tedious tasks of building with old LEGO is cleaning old LEGO. While LEGO usually stands the test of time pretty well, the bricks that come from either my childhood collection or via BrickLink, can be in pretty much whatever state of dirtiness and weariness – and all those small studs and nooks and crannies don’t make the job any easier.

I have written about cleaning LEGO before (see Washing LEGO and Washing LEGO II) and I thought I’d again add a few notes to the discussion based on my recent experiences with a used 7864 12 V Transformer, which really is a new kind of LEGO cleaning heck on Earth. Three things require new approaches: one, I can’t really sink a transformer into water; two, all the studs on top of the transformer are hollow; and three, most of the transformer is covered by a matte texture.

Wiping LEGO clean

The fact that this is an electric device meant that large amounts of water could not be used. After the usual damp rags, microfiber cloths, vacuum cleaners and a little compressed air all doing their part but not enough, I went with cotton wool in the form of wads and sticks. Especially the cotton sticks proved successful in getting into those hollow studs and being able to circle around them tightly. Add a drop of water on the first go and the finish off with a dry cotton wool stick – and repeat.

Warning: The matte texture that covers most of the transformer and perhaps many other 1980s LEGO Trains 12V components is rather sensitive. Looking at the used transformer I have, it has glossy scratches all over it – and even a strong push from the cotton wool stick was able to scratch the matte surface further! You will want to be extra careful with the matte areas, so that no pin-pointed force is applied over them. Luckily the studded areas are glossy and seem to be able to handle more of a beating (they are the ones gathering most of the dirt anyway).

Maybe I will do a little further write-up on all the ways you can hurt your LEGO, later.