I know there are a lot of thread on shelf life for face make up but I couldn't find one on nail polish.
I'm going through and organizing my nail polishes. I'm finding that I have some bottles that are over 10-15 years old. Obviously, if the nail polish is thick or goopy, it is time to toss them. But what about the ones that are thin and rarely used, and look ok. The color has separated on some, but when I shake it up, it looks fine. Is there anything wrong with using really old nail polish or is it time to toss these too?
I think you can mix a few drops of nail polish remover in to make it 'like new'...correct me if I'm wrong.
You'll destroy your polish if you add nail polish remover. You can buy an inexpensive bottle of thinner at a beauty supply store such as Sally or Ulta and restore you polishes to new. Don't throw out those favorite colors just because they're goopy! Nail polish never goes bad.
I've used crap thinners before, but this one improves even brand new polishes that are just a little too thick for my liking. It's heaven.
You want a thinner that's just: Butyl Acetate, Heptane, Ethyl Acetate. If you see a large bottle it's most likely: Butyl Acetate, Heptane, Ethyl Acetate and Isopropyl Alcohol.
Guess what? You're just getting extra alcohol. You'll need more thinner to fix your polish and it will evaporate quicker. Get the good stuff. If it's a giant bottle of thinner, it's too good to be true. With Nail Tek's Extend I only need a few drops to fix a too-thick polish, literally.
Nail polish remover used as thinner will destroy the quality of your nail polish. It will chip faster and any strengthening benefits will most likely be compromised. You might also cloud-up your color. I'd rather chuck a bottle than thin it out that way.
OP : Re "Obviously, if the nail polish is thick or goopy, it is time to toss them. " No need to toss them, just use a nail polish solvent like the others have mentioned above.
as for those which separate, just give them a good shake, let it stand for a while (otherwise, u get bubbles when you apply), then if you wish to, before you apply, roll the bottle using both hands and it is ready to be used.