Just finished testing polyurethane dry times across different conditions. Here’s what I found in my unheated garage during winter.
At 45°F, Minwax Fast-Drying Poly took almost 8 hours to be tack-free – nowhere near the “2-hour dry time” on the can. That’s at 60% humidity.
Moving the piece inside where it’s 68°F made a huge difference. Same product dried in about 2.5 hours.
Key Takeaways
- Temperature matters more than humidity for oil-based poly
- Below 50°F, expect 3-4x longer dry times
- Water-based poly is more forgiving in cold
- Don’t trust the can times in winter
If you’re finishing in a cold shop, either bring the piece inside or wait for warmer weather. Trying to rush it just leads to tacky, never-quite-cured finishes.
