One gallon should do you fine. You thin it out some anyway according to instructions. Make sure your traps dont have pitted rust . Fine surface rust is okay . ALso do two coatings possibly three. Two light coats and letting dry in between is best. If your traps have pitted rust , derust by some method that you feel comfortable with , then dip. Dip on a sunny breezy day. If you do it early in day , its possible you can dip before dark again. Good luck and happy dipping