If you've been doing a home-improvement project with polyurethane, you should be wearing gloves. If you didn't wear gloves and got polyurethane on your skin, it can be difficult to remove. Scrubbing is futile without the right ingredients, so don't rub your hands raw. Luckily, with a few ingredients from your local hardware store, your hands will be polyurethane-free in no time.
Rinse your hands (or whatever skin you've gotten the polyurethane on) in mineral spirits. You can purchase mineral spirits at the hardware store or at an art supply store.
Rub your hands together vigorously for several minutes.
Rinse off the mineral spirits.
Scrub your hands with lava soap for several minutes. You will feel the polyurethane start to lift. You can purchase Lava soap at your local hardware store.
If there is still residue left on your hands, soak them in mineral spirits for several minutes, then repeat the process again.