I bought a cheap ryobi power planer and it was working fine. But then one day it started taking out huge pieces of foam out of my blank. I am using xps which is very similar to poly. I know that eps can have that problem but this was strange. I thought it was because I bought a cheap planer. So I ended up getting the modified hitachi for $400. I used it and it started taking out chunks off the foam.
I feel that I am doing something wrong. Please help
You’re not doing anything wrong, and it’s not your planer’s fault.
Extruded polystyrene foam just tears like hell under the planer. PU foam tears if you go really fast, or of your blades are very dull. EPS doesn’t tear at all, but if the beads aren’t fused well you’ll get some pull-out of beads.