Sure. We first painted with a base primer to seal properly the MDF. Then we used putty to fill in the imperfections, sanded it down, gave it a second coat, putty again and sanded it down again. Then we applied an automotive putty (that's what its called here) to correct all the imperfections and joints properly. This was sanded down and reapplied until it looked like a sealed piece of plastic, then we gave it the first coat of the black polyurethane paint. It will be sanded down again for any imperfections, and if all is well, will proceed to give it the last coat of polyurethane.
Let's see how they turn out!!