Repliflow is a specifiacly designed resin based spray for smoothing rough surfaces. Originally produced for the 3D printing market, but can be used on most rough surfaces, including sealing mdf in just a few coats saving time and and effort sanding and flating. We have timed this to a standard 2k primer and in time scale it is 10 times quicker. 
Dries in an hour and ready to paint. SEE TECH DATA SHEET FOR ALL MIXING AND USAGE INSTRUCTIONS.