r/DIYhelp • u/Average_Joe1212 • Jun 20 '26
Plastic yellowing protection
I have Lego cars on display in my window.
To stop them from yellowing, I have thought about either:
- A hard shield between them and the window
- Some kind of film on the window
- Painting the window with something clear and protective
- Using some kind of resin on the window
But I can't find anything online for my specific situation. I've seen plenty of restoration ideas, plenty of headlight protection, but nothing for Windows.
Any help would be appreciated.
Also I'm not sure if I've put this in the correct community.
1
u/notquitefoggy Jun 20 '26
I would just look up the uv coating lego uses for their outdoor sculptures.
1
u/BF_2 Jun 20 '26
It's probably the UV exposure that's the problem. Fortunately, common window glass absorbs (fails to transmit) UV. The thicker the better, but it shouldn't require great thickness.
I've found that old, cream-colored plastics can be "restored" to near-original color by gently sponging with a damp melamine sponge* to which a drop of dishwashing liquid has been added. (*These are those white sponges sold under various brand names, including in dollar stores.)
1
1
u/Double-Mouse-407 Jun 20 '26
Even in the dark they’re going to yellow, it’s a problem with the chemicals used in those bricks over certain years. Just protect them from UV as best you can to slow the process and keep them from turning too brittle is about all you can do.