Is it normal for oil based urethane finishes to darken with age?

Yes, these finishes will darken with age, even if stored in plastic cans that allow light to filter in. However, this will not harm performance if properly stored after opening. Here are some steps to store oil finishes.

1. Decant the amount you'll need into a foil covered bowl and reseal your can right away.
2. Be sure to REALLY clean the chime and the lid of the can to assure a tight seal.
3. Use Bloxygen to help remove excess oxygen from your can of finish to help preserve it longer.
4. Store your sealed cans upside down.