We just finished applying Liquid Roof to our 36 foot motorhome, so I can offer some tips from our experience. I spent a lot of time prepping the roof before sealing it. We removed all the vent and A/C covers and cleaned and sealed their edges. I found that the best way to remove the white, chalky “top coat” residue from the roof was light pressure with a green scrub pad using a random orbital polisher and lots of water. We masked off the perimeter of the roof and applied Liquid Roof around the vents and A/Cs and the the rounded edges of the roof with a brush and 2 inch roller.
Tip #1: I recommend that the perimeter masking include plastic sheeting down the sides of the motorhome. This would allow the top coat of Liquid Roof to level itself and flow over the edges giving an even coating and lessening the appearance of drips. We would still put a smaller first coat around the edges and not fight against drips from a heavier coating.
Tip #2: Measure and mark sections of the roof surface equal to the 42 sq ft per gallon coverage recommendation and pour each gallon in a section. Use a small squeegee (10 inches or so--bigger isn't better for this job) to spread the Liquid Roof and let it settle out on its own. If a roller is used to cover missed areas, use it sparingly and gently to avoid thinning the coating. (Our application ended up thinner than recommended as we didn't pre-measure the roof for each gallon and were overly aggressive with a roller.)
Tip #3: Mix one gallon at a time. Use a heavy duty drill for mixing. A cheap homeowner drill will be very taxed in mixing Liquid Roof. Don't worry about color match among gallons as any color differences, if any, are insignificant. One gallon at a time is tough enough to mix.
Final tip: Two or more people should be available to do this job. One on the roof spreading a gallon at a time, and another mixing the next can. The person with the stronger arms should the mixing!
Good luck with your project. Our roof came out great, even though we now know it could have been easier and better with these tips.