I have used the PolyFiber water based primer "SmoothPrime" and applied it with a roller and gun. I find it very easy to work with and a pleasure to sand ( compared to almost evrything else). I have found that I needed a smaller syringe to measure the crosslinker in the amounts I wanted to use, but these were no problem to find. If you would like any additional information, just let me know. Kurt Winker 173 FGE