Should I warm the resin and hardener in hot water before mixing?

Warm the resin only, and only when it's too thick to mix and flow well. For UltraClear Bar & Table Top Epoxy or UltraClear Art & Craft Epoxy, set the resin container in a bucket of hot tap water for 15–30 minutes before mixing. That lowers the viscosity so the epoxy mixes more easily and flows properly. (Bar & Table Top Epoxy is the thicker of the two.)

Never put the hardener in the water. The hardener should be at room temperature before use, whether you're mixing a seal coat or a flood coat. Heating the hardener can cause overheating and flash curing.

Two things to plan around: - Warm resin cures faster. Warming the resin shortens the pot life and working time, so have everything ready and pour as soon as it's mixed. - Don't use a heat mat under the project while the epoxy cures. It builds up excess heat, and overheating makes the epoxy cure too rapidly.

Warming the bottle doesn't replace a warm room. Keep the room above 75°F for the full working time and for 72 hours afterward so the epoxy cures properly.