I went and read their application instructions - it says one coat. My guess is, though, that you didn't apply a good one. It also says to only apply enough that can be absorbed, but it talks about spraying it on, then brushing to even it out. If you applied it too thin, it won't work properly. Did you use as much as it says? They give 'normal' coverage specs, and if you got significantly more coverage, you really didn't!