Okay, I'll try to get everyone in one post here.
Jeff:
Is plastic varathane safe? .. according to Varathane it is "baby safe". Now as for reality .. I'm not sure who's baby they are putting on the line here. I tried it on one of my cages and even after two weeks of curing time, it smelled so bad I couldn't stand to have it in my room. I finally covered it with a water based acrylic and that fixed things. I imagine if you could get it to cure it would be fine, but it looks like that takes a loooooong while.
Gymrat:
An oil based paint ... hmmm. Oh well, it's on the outside so that's not too bad. Keep it well ventilated for the first few weeks just to be on the safe side.
Jason:
You're probably thinking of the Varathane liquid plastic. It's a paint on melamine (sort of) coating. I imagine it is a paint with melamine additives. It's not quite the same as the melamine plastic that is fused to the wood. As I told Jeff, it does have a long cure time, but works well if it is sealed with a water based acrylic (either Minwax water based Polycrylic or Varathane water based Diamond Seal work good)
There .. all done and a minimum of ranting.