Plastic discoloration?

Wayne-I've noticed that too-but no clue as to why it happens.

It's probably caused by outgassing of chemicals from the plastic. It shouldn't cause any problems. Unless you weren't planning on painting, that is!

what about the clear parts

On the ESCI 1/48th Cessna, the clear parts fogged. The kit was not stored in a particularly hot area, but could be humid at times. The parts stayed clear on the Bearcat.

i wonder if it has anything to do with the brand
i have seen same with an additional problem
some of the plastic had become a bit brittle
and the glue reacts differently on diff kinds of plas

Nothing has been glued on he Hawk Bearcat. Some things were glued on teh ESCI Cessna before it was put away. And while straightening up yesterday, I saw the discoloring on the sprue and some parts of my Huma He 280. that's three different brands, but if memory serves, they could have been bought around the same time, many years ago.

Plastics generally have a bunch of other things added for a number of reasons.

One of note is a plasticizers, which are smaller molecules that basically soften the plastic by preventing the molecular chains from folding upon each other as tightly as possible. They can leach out over time, resulting in the material becoming more brittle and a greasy film covering the plastic (though this takes several years).

Plasticizers, the molecular chains themselves, and other additives (fillers, heat stabilizers) can also degrade with time (especially in the presence of heat or light), resulting in yellowing (typically apparent in white materials, but can be observed in others).

Ckf-stop it, you're making my brain hurt. I've only seen the discoloration on white plastic and any clear part fogging I was able to fix with polish.

Since the Cessna was the only one that the clear parts fogged I would attribute that to outgassing of chemicals from the glue itself.

Humidity is a bad thing, high humidity is quite often combined with heat. It doesn't take much to wreck plastic.

The lesson is buy less kits, build more and use up that stash!

Bill (who's thinking now about the kits he started and reboxed for "later")

Can't buy less kits. When they are half price or less, you have to jump on them. Some of the kits may not be the greatest, but you can't get them any more. And there are always these great plans in your mind, how you are going to build them. If I spent the required time to build my stash down, I probably wouldn't have a wife.

The humidity i"m dealing with is the damp basement.

Wayne-always remember to keep your stash in the dining room!

Actually, I have a nice drywalled room in the basement with an art metal office desk to work on, a couple of bookcases with my reference stuff, a couple more with part of my stash, tv, vcr, and dvd player. My wife is tolerant, but I only get to work on one at a time upstairs.