We made some MDF one-piece raised panel doors this week. During finishing we're noticing cupping of the doors in both directions on the front side. Is this typical, or is it maybe due to unbalanced coats of finish front to back?
From contributor J:
Could be due to the rigidity of the machine.
Panfiber Elite (not to be confused with regular Panfiber) works well. Medex works best of all of the types I have tried so far. These panels are a bit more expensive, but in addition to reducing warp, you will save a ton of time in the sanding and finishing area with either of these boards. It will far outweigh the added cost of the MDF.
Try a good high solids primer for profiled pieces, like ML Campbell Clawlock. It is a catalyzed primer, but sands very easily. Also well worth the small added expense when sanding time is taken into account.