Sole Discretion

The topic of plane soles – as in smooth vs. corrugated soles – is one that often evokes impassioned opinions. Thankfully, it doesn’t seem to crop on woodworking fora as often as other touchy subjects – like, say, sharpening or SawStops. Many users have no preference one way or another, but those who have formed a opinion typically view corrugated soles with a level of contempt normally reserved for laser-guided handsaws.

Paul Sellers has made his opinion known:

…corrugated soles grab shavings, especially super-thin ones that cling to the grooves of corrugated soles. Even flat soled planes do this. The problem inherent to corrugated soles is the grab and mush up in the grooves and on subsequent forward thrusts, damage the surface you are supposed to be smoothing. No craftsman I ever knew favoured these planes…It also damages corners and edges of wood when you start to plane angles such as chamfers or form bullnoses to things such as box lids, window sills and stair treads.

Yikes. Sounds like something I’d like to avoid. So what’s the point of the corrugations in the first place? Paul addresses that as well:

The corrugated sole was produced in Bailey pattern planes for a period with the intention of reducing the surface area of the sole to further reduce the friction of the plane on the surface being planed. Indeed it does do that…

Paul is actually kinder to corrugated planes than some other authors, who opine that corrugated soles do nothing to reduce friction, making them worse than useless. Well, I have been using the three planes pictured below for the past several years, so in the name of good fun, I would like to offer my contradictory assessment:

From top to bottom: Craftsman No. 5, corrugated; Stanley No. 6, smooth; and Stanley No. 7, corrugated.

Aside from the Stanley No. 4’s that you see peeking into the upper right corner of the photo, these three planes chew up the bulk of the shavings that are produced in my woodshop, and they have done so for quite some time. The No.7 is my most recent acquisition (from 5 years ago), while the No. 5 is my oldest companion (the first decent hand plane I ever owned, from 10 years ago).

So without further ado, here are a few unfiltered observations about the performance of these tools, with regards to the sole:

• The corrugations do indeed drastically reduce the friction; I can easily use the No. 5 and the No. 7 without wax, whereas the No. 6 is nearly impossible to push once the wax wears off.
• I don’t necessarily view the additional friction of the smooth sole as a bad thing. It’s just a gentle reminder to wax your stupid planes.
• I rarely/never have an issue with shavings clinging to the corrugated soles. This is very likely related to the fact that I rarely/never make “super thin” shavings with my corrugated planes. The No. 5 is set up as a fore plane; it has a strongly cambered blade for hogging off meaty shavings, often cross-grained. The No. 7 is used almost exclusively as a jointer, for truing up edges; the blade is sharpened straight across, and it takes substantial shavings that curl up into neat, tight spirals. There’s simply nothing to get caught in the corrugations. None of my smoothing planes have corrugated soles, but I can certainly see how this might be an issue with their tissue-thin shavings.
• Finally, I’ve never had much of problem with the corrugations damaging chamfers or bullnoses. For one thing, I would never use my jointer for this task (no use pushing more weight than necessary). And secondly, if I do use my fore plane (AKA No. 5), it’s only to hog off the bulk of the waste; I would inevitably follow with the smoothing plane set to a finer cut to tune up the edges.

In summation: Corrugated planes are fine for most situations. I think they’re particularly well-suited to jack planes/fore planes that take the coarsest shavings and can benefit from a little friction reduction. I would personally prefer a smooth sole for smoothing planes, but if I found a great deal on a corrugated No. 4, I certainly wouldn’t pass it up. For try plane/jointer planes, I don’t think it makes a nickel’s worth of difference either way. Just be aware that with the more massive smooth-soled planes, you’ll definitely need to keep the sole well-waxed, which is frankly a habit that you should get into anyway.