Hi Galindo,
Thank you for reviewing our paint. I'm sorry to hear that you can still see the Greenboard through 2 coats of primer and 2 coats of paint. This product is a very thick coating (1 gallon will cover 75-125 sq. ft.) and is best applied with a high quality 1 1/4" nap roller to achieve the correct film thickness. So we can help get your project back on track, please feel free to reach out to us directly.