The scrub plane is unusual in that it doesn’t fall neatly into the traditional English system of classifying bench planes. Rough stock was prepared first with a “fore plane,” which is a metal or wooden plane that’s anywhere from 16″ to 20″ long and has an iron that has a significant curve to its cutting edge. Then you refine the board’s surface with a jointer plane followed by the smoothing plane.
The scrub plane doesn’t jibe with this English system. The scrub is between 9-1/2″ and 10-1/2″ long and its iron is even more curved than what I’ve seen on fore planes.
Another part of the puzzle is when you consider that Stanley made the No. 40 scrub plane between 1896 and 1962. The scrub plane wasn’t introduced until after the Industrial Revolution and the invention of powered jointers and planers. In 1896, fore planes were fast on their way to becoming relics , so why would Stanley introduce such a plane as the scrub?
One answer might be in Stanley’s 1923 catalog. It states that the scrub is for “planing down to a rough dimension any board that is too wide to conveniently rip with a hand saw…¦.” So the scrub plane was perhaps designed instead to work on the narrow edges of boards, to quickly reduce a framing member in width before the house carpenter had a portable circular saw (an invention of Skil after World War II).
If the plane was indeed a carpentry tool for ripping, this might explain why Stanley japanned the entire body of the plane, including the exterior sidewalls. Home sites are a lot less friendly to cast iron than workshops. It also might explain why so many of the vintage No. 40s I see look like they were dredged from the bottom of the sea.
This theory also makes sense from a workholding point of view. The fastest way to reduce a board in thickness by hand is with a hatchet or drawknife. But neither of these tools would be convenient to use with the workholding devices common in the long carpenter’s workbenches shown in “Audel’s Carpenters and Builders Guide” (Volume 1). However, working an edge on a long carpenter’s bench with a plane is a natural and simple operation.
And so it was time to try some new tricks with our scrub planes in the shop.
Once you start working with a scrub plane you realize why they are so popular. They are a blast to use. Using a smooth plane seems fussy and slow once you’ve reduced a board in thickness with a scrub. It can be done by working diagonally across a face one way and back the other way. Then check your work with winding sticks and go after the high spots on the face. When the board won’t rock when this scrubbed face is pressed to the benchtop, you’re ready to move on to the jointer plane.
This is a useful skill , even today , when dealing with boards that are too wide for your jointer or planer. Instead of ripping them into narrower widths (a crime, really), you can true up your wide boards to make impressive tabletops or door panels.
And though I do regularly use my scrub for this sort of operation, I’ve found that my fore plane (a beat-up Stanley No. 5) is more reliable at truing a board’s face. The longer sole of the fore plane is one of its assets.
I also use the scrub to simply texture surfaces before finishing. With a sharp iron and a steady hand, you can produce a regularly scalloped surface with a scrub plane. It can create a rustic look, and can even be successfully used in contemporary furniture.
Another fine use for the took is in removing the backsides of baseboard moulding to fit it against a less-than-stellar drywalling job. I found out this excellent use for the tool when trimming out an addition to our house a few years ago.
But then there’s the matter of the scrub plane’s true mission in life. Could it be a good tool for reducing a board’s width? Is it a ripping plane? Intrigued, I fixed a long length of framing lumber to my bench and tried to remove 1/4″ from the edge. Removing that amount of wood from an 8′-long 2 x 12 would be a good deal of effort with a rip saw.
The scrub did the job remarkably well, especially when I didn’t try to use the tool like a jointer plane. Instead of taking a long continuous pass on the edge, I started at the left end of the board and took short, choppy strokes to get down to my scribe line. It was indeed faster than any ripsaw I’ve used and was on par with the stock removal rate of a drawknife (but with more control). I’m not ready to call this mystery solved. But I am going to start collecting some more books on early 20th century house carpentry. Maybe they will help reveal the true nature of this aggressive and durable plane.
– Christopher Schwarz