Applied with a spray gun and brush to the inside of my Kawa wool forge. Also liberally cleaned the 2700 fiberboard I used for the floor. Very easy to use. Dry clear. It took 24 hours to dry as expected. My forge is small (14x7x6) and I dried it in the basement next to the boiler with a working dehumidifier. Did a few test runs. No questions. The debris in the photo is just dross from the carbon steel I tested with.