Scrub plane are essential tools for anyone who uses split or rough sawn wood. These will quickly flatten and dimension boards, as they remove thick pieces of wood with every pass. How do they do that? With a little engineering.
The classic German scrub plane–this one is an Ulmia–with a wide throat and a highly convex blade. This is designed to take off a good deal of stock in a hurry, and it does. Now for a home made scrub.
Stanley #5 Jack planes used to be about the price of a High School lunch, and some of the older ones were the cheapest. This is a pre-1902 plane made without a Frog adjustment screw, which is pretty much useless for a scrub plane anyway. I just ground the cheap Stanley blade into a convex cutting machine. I do need to file the throat wider, so those Walnut shavings don’t clog as often.
So scrub away. These planes will save hours of time, and many obscenities.