What Does a Jointer Do in Woodworking?


Ever wondered how lumber from trees is standardized for use in woodworking projects? You’ve probably heard of a jointer, but few know how to use the machine.

A jointer is a machine used in woodworking to shape lumber boards by flattening and smoothing them. It corrects naturally occurring defects in the wood, such as warping or cupping, making lumber ready for use in various projects. The result is wood with one flat side and a square edge.

Continue reading to find out everything there is to know about a jointer in woodworking and whether you need to get one for your projects.

What Is a Jointer?

A jointer is a machine that primarily creates flat edges on rough lumber to make it easier to join. It is part of the stock dressing, creating accurate geometry to facilitate better structure in finished projects.

You might not need a jointer in your project if you purchase ready-made wood panels that an expert has already dressed. You can find these pre-made panels at various in-person and online stores. 

However, it’s worth noting that the cheapest way to buy wood is to buy it rough. The problem is that the wood will undoubtedly have some bends and warps—defects that need to be corrected. 

Many beginners in woodworking confuse a jointer for a planer, but the two are very different machines, each with a specific purpose and method of dressing lumber stock. I’ll elaborate on this later. Just remember that both tools are essential in woodworking.

Operating a Jointer

First, it is important to understand the anatomy of a jointer because it needs to be well-tuned to function effectively and efficiently. It is two parallel tables (the infeed and outfeed tables) with the latter set at a slightly higher plane. In between the two is a cutter head that quickly shaves off the difference between the two.

Rough wood inserted through the infeed table should come out of the other end flat with most (if not all) of its defects removed. Experienced woodworkers can remove all the natural imperfections in rough lumber after running it through a jointer only once. It takes practice to perfect the art of joining.

Here are a few basics of operating a jointer that will enable you to achieve better results:

  • Start shallow when setting depth. Remember that you can always run the stock through the jointer a second time if you didn’t remove enough material on the first try. So, be conservative when setting the depth, and readjust as you go. 
  • Position boards with the defects downwards whenever possible. Every board will have a different fault, so you’ll need to consider which way it is facing when feeding it into the jointer. The blades of the cutter head are below the board as you run it through the jointer, so you must have the defects facing them.
  • Apply consistent light pressure when feeding stock into the jointer. Pressure is significant if there are twists in the board because it might rock as you feed it through. Don’t push too hard. All you need is to guide the wood towards the outfeed table. 
  • Use the fence to limit blade exposure and stay safe. The fence can also help you square the edges of a board when used with a combination square.
  • Safety first—wear all the necessary safety gear such as goggles and a helmet. Additionally, most woodworkers recommend using push blocks so that your hands are never too close to the cutter head.

Maintenance and Tuning

While the basic operation of a jointer is simple, to get the best results, you need to tune the machine correctly and maintain it. Maintenance usually means waxing your jointer’s surfaces to ensure there isn’t too much friction. Ensure that the device is unplugged before you wax it. Remove excess wax to prevent slippery accidents.

Tuning a jointer involves firstly ensuring that the two tables (infeed and outfeed) are precisely aligned parallel to each other. You should always square the fence at 90° to ensure that all your jointed wood is squared correctly.  

Jointer vs. Planer

As I’ve mentioned earlier, many people confuse a jointer and a planer. Although both tools are for stock dressing, they operate differently and facilitate different stages of the dressing process. You should only use a planer after the wood has run through a jointer.

The term “planer” is the UK and Australia equivalent of what Americans call a jointer. Keep this in mind when reading information or purchasing woodworking machines online.

A planer (also known as a thickness planer) is a machine used solely to make wood panels of consistent thickness. The planer shouldn’t be able to correct warping, cupping, or most of the common defects found in rough lumber.

Generally, the stock dressing process begins with jointing, planning, and finally sawing the wood to the desired shape.

The Machine You Need To Get

Because both machines play essential roles in turning rough lumber into something usable, I highly suggest you get a jointer and planer. You’ll want to own both of these devices, especially if you are serious about your woodworking projects and plan to complete many of them.

However, it’s worth mentioning that you buy wood panels that are already dressed and won’t need a jointer. Ready-made, dressed wood panels are more expensive than rough lumber, which is why most carpenters tend to invest in a jointer.

In any case, don’t rush into getting a jointer if you are still new to woodworking or if you don’t intend to continue woodworking beyond your current project. Simply put, a jointer is a long-term investment for those serious about woodworking projects.  

Final Thoughts

A jointer plays a critical role in woodworking by removing any sort of defects found in rough lumber. As buying dressed wood is much more expensive, woodworkers prefer to buy a jointer to dress the wood themselves. A planar is an entirely different machine used in stock dressing routinely.

Jedediah Arnold

Jedediah has been working with epoxy resin for a couple of years. When he started, he wanted to share everything he learned as he learned it which continues.

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