yellowed siding - need help

Thanks for your suggestions.  The only thing "oozing or gooey" was AFTER I tried Goof-Off, fortunately on the back of a building.  Before loading the model for the trip, I did try Windex - no luck there either.  The model has been successfully moved and I did point out the yellowing to my brother.  He remembers re-painting the actual house  back in the '70's and since the house was built prior to the 1850's, he contributes that the yellowing indicates the actual house just needs a new paint job, LOL!  As in he's looking at the yellowing as more authentic to the house.

Hopefully someday my nephews will take up model building (ages 12 & 13 now).  Besides fixing up the house model, I've got many more models for them when I "kick the bucket."

I'm glad I found this site and although I don't build models as frequently as I used to, I'm sure I'll have other questions or things to look up in the future.

Thanks!

Rob

Often,  plastics yellow when they are stored in the dark, but this doesn't sound like the case here. If it has been in a Plexiglas box, it probably has been shielded from most UV light. Heat can also induce yellowness in plastics.

My guess is that the plastic has degraded and that you will not be able to do anything about it apart from replace the parts. You can accept the changes and call it patina.

One last thing, if it is oozing a sticky substance, wear gloves, this is the plasticizer migrating to the surface. They are often nasty chemicals which you don't want in contact with your body.

Unfortunately, that yellowing is probably ultraviolet light damage to the vinyl - I'm not sure you could do anything about it short of repainting.