Since i have to clue what to the play the past weeks, i decided to tumble over my storage boxes of LEGO and restore a childhood set, week and a half well spent! After more than 20 years being a shipwreck inside storage boxes, she's finally restored into her full glory! Sails were stored in between the manual at the bottom of the big manuals pile, so they're in great condition. The White and Grey pieces had a Hydrogenperoxide bath for about 6 hours, they wern't super yellow, but OCD
Awesome! @TheDeeGee I've got a Technic 8880 that I'm going to take apart and rebuild - it's been together for over 20 years and majority of the white bricks have gone a really nasty yellow. What strength hydrogen peroxide did you use and what exactly did you do to restore the bricks to their proper colour?
3% Hydrogenperoxide, and let them sit in the sun outside for 6 hours, depending on the yellowing you may need more hours. Just make sure the parts stay submerged, and every 30-45 minutes remove the bubbles that form on parts. It needs to be a clear sunny day, 20 degrees celcius or higher is prefered. Wash the parts beforehand though, they need to be dust free before de-yellowing. I also suggest taking the parts out of the peroxide if you need to treat them again the other day, just rinse them off with water for the next day. You can use stronger peroxide to speed up the process, but it can also damage the parts. Also ONLY treat White and Light Grey pieces, colors like Red and Blue will fade. If parts have prints on them that's fine, stickers need to be removed.