If the blades are worn or if you are comfortable about changing the
blades, go ahead and run the painted boards. There is a definite
probability that you will ding the blades in the process. The paint
will not harm the machine, just the blades. It may well be worth a set
of blades, especially on these new benchtop miniatures that have the
easy set blades. If you've ever set knives on an old planer you would
know why to hesitate about any chance of knicking a set of knives.