I got my first set of molding knives for my Jet 13" planer/molder and gave it a try last night. In the manual, it says to cut a 13" x 31" piece of MDF and bolt it to the table, then you clamp/bolt fences to the MDF to keep your work piece sliding exactly under the molding knife the same way every pass. Anyway, one side effect of the MDF is to give you longer infeed and outfeed tables at the expense of 3/4" less vertical clearance. The only negative I can think of is that your height gauge is now 3/4" off. However, one of my biggest complaints about this planer is the short infeed/outfeed tables.
Has anyone put longer feed tables onto their planer? This would seem like an easy way to accomplish it. Possibly I would need to build a small torsion box or use rails to keep it from sagging. Longer tables would solve any instances of snipe and make planing long boards much easier.