Take a look here Jack
http://www.infinitytools.com/Carbide-Tipped-Knives-For-DeWalt-735-Planer-3-Pc/productinfo/CPJK-041/
woodworking classes, custom furniture maker
The blades can be sharpened once or twice but carbide would be a good choice and hope you don’t hit nails or the like .
Klaus
Thank you Jim and Klaus. I’m going to try the carbide and see how they work.
Jack
Klaus has a very good point about nails and screws if you use used material.
woodworking classes, custom furniture maker