Infill Planes

This is an excerpt from “The Anarchist’s Tool Chest” by Christopher Schwarz.

These planes earn their name because they consist of a metal shell that has been “infilled” with wood. And they also have been “infilled” with a fair amount of mystical hooey. Don’t get me wrong, I like infill planes for what they are (well-made, beautiful and functional tools), but I haven’t chugged the infill Kool-Aid that makes one believe they have superpowers.

I can say this because I have worked with many infills during the last 12 years. I’ve used $100 pieces of clap-trap garbage and a $10,000 masterpiece from the shop of Karl Holtey (pronounced Hol-tie, FYI), the grand master of custom planemaking.

They are just planes, and they face many of the same trade-offs that the metal, wooden and transitional planes do. Wood moves. Metal can be difficult to work.

So here are their advantages: They have a metal sole that may or may not need truing when you get the tool. After the sole has been flattened, it rarely goes out of true unless the tool is dropped, run over by an automobile, or the wooden infill inside the shell distorts the metal significantly when the wood moves.

Infills have scads of mass, which some woodworkers prefer. The weight really can keep the plane in the cut with less effort. Most infill planes have a screw-powered lever cap (though some infills secure the iron with a wedge). The screw-powered lever cap is both an advantage and a disadvantage. Its advantage is that you can screw down the iron with almost superhuman force. This creates a stable cutting environment and can close up a slight gap between your iron and chipbreaker that would spell curtains for other types of planes.

It also can make your plane’s iron difficult to adjust or – in some cases – be plane suicide. Most infill planes lack mechanical adjusters that control the depth of cut – you use hammer taps. However, infills that have adjusters use a mechanism that’s usually called a “Norris-style” adjuster. These are sometimes, but not always, fragile.

So if you cinch down your lever cap with lots of force then adjust the iron, you will wear out the adjuster quite quickly, and perhaps even strip the threads.

One of the other advantages of infill planes is hard to quantify. Most woodworkers (me included) find them fetching. So as a rule they are better cared for (like a sports car) and rarely abandoned to rust (like a Vega).

The disadvantages of infills are real. Because the iron is bedded on both metal and wood, you can encounter some problems with this marriage of materials. The metal won’t move, but the wood will. The result is the iron won’t be bedded securely, so you get chatter or inconsistent results until you file the bed flat.

Also, be wary of new infills that are filled with exotic wood. Exotics are notoriously hard to dry properly. And if your infill isn’t dry it could distort or crack as it acclimates to your shop. Always ask the seller or the maker about the moisture content of the wood. If he or she is not sure, you should be on your guard for possible problems ahead.

Infills don’t have movable frogs, and I know of only one infill that has an adjustable mouth. As a result, the mouth aperture is fairly immutable. You can open the mouth with a file. But to close up the mouth, you are going to have to invest in a thicker, custom-made iron or in a welding class to patch the mouth.

— MB