This post is the result of a comment on a recent post asking for a recommendation of a scrub plane. I cannot make recommendations without first explaining the basis of my viewpoint, so here we go!
A scrub plane is a short-bodied plane (about 9-10 inches long) with a radiused edge on the blade. Its primary purpose is to rapidly remove material – one of the first steps in dressing a wooden board.
I made this scrub plane in 2013 in The Scrub Plane Build-Off. The body and wedge is yellow birch, the sole is Lignum vitae, and the blade is a replacement E.C. Emmerich scrub plane blade. This is one of my favourite tools, and it gets more use than any other tool that I have made.
Above all, the body of the plane must be comfortable to hold. When doing a lot of planing, I periodically change my grip, working both left- and right-handed, pushing, pulling, and working side-to-side. Some metal-bodied planes are not comfortable to use in all these positions.
I tend to use a scrub plane vigorously to quickly work down a high spot and get the board roughly flat. Having a lightweight plane makes this work easier and less labourious. Mass may be an asset for a smoothing plane but it’s a disadvantage for a scrub plane. Wooden bodies are usually lighter than metal bodies.
A smooth, slick sole makes planing easier as well. Because the scrub plane is frequently used on rough material, sometimes colliding with steps in a rough surface, the sole must also be very durable. I can’t think of a better material than self-lubricating Lignum vitae, an incredibly dense, oily exotic wood. A metal sole frequently lubricated with something such as wax, is also a good option.
The sole should be relatively flat, but it is not critical that it be absolutely flat.
To allow the plane to take thick shavings, the mouth must be at least as wide as the shavings are thick. Since the scrub plane is not a finishing tool, a tight mouth is not necessary. I intentionally made the mouth on my plane quite wide. You can’t tell from the picture below, but the blade is set to take a moderate cut.
The radiused blade allows the plane to take a very thick shaving with relatively little effort – much like a curved carving gouge versus a straight bench chisel. Even though the blade is about 1.5″ wide, the shavings that it makes are only about half that wide.
As with any plane, it is extremely important that the blade has good support – especially right near the sole – and is sufficiently stiff to prevent vibration. A 1/4″ thick blade may be helpful, but it is not necessary. The blade on my scrub plane is just under 1/8″ thick and I’ve never had an issue with chatter.
A good quality steel is worthwhile, as the scrub plane blade sees lots of abuse. Aside from taking heavy cuts, the blade is more likely to be rammed into knots, run through sand, rocks or other debris. I think that I have sharpened the blade on my scrub plane only a few times since making it seven years ago – and not due to lack of use!
Blade adjustment mechanisms
A precision depth adjustment mechanism on a scrub plane is not critical, and I would actually find it bothersome. I don’t change the depth very frequently, but if I need to increase the depth of cut, I hit the top of the blade with a mallet if convenient, or simply hit it on an unsurfaced area of the workpiece. To retract the blade, I strike the back of the plane. After either adjustment, I tap the wedge in to ensure the blade is held in tightly.
What to look for in a scrub plane
- Comfortable grip that allows multiple grip positions
- Wide mouth
- Smooth sole that is or can be made slippery
- Quality blade that will stay sharp
Need a scrub plane? Build one!
If you have any interest in building a wooden hand plane, this is a great place to start. A scrub plane does not need to be as refined as other planes, so it’s a great opportunity to learn. Or, if you’ve already built wooden hand planes, this should be a quick and easy build for you.
If you would rather buy a scrub plane, choose one based on the four points above. I would suggest looking for a wooden model, such as the E.C. Emmerich. And I can vouch for the quality of the steel.