How to Use a Thickness Planer

How to Use a Thickness Planer

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If you need to flatten some boards and either have or are planning to buy a thickness planer, you are in the right place.

From choosing the right planer all the way to getting value out of it, this article will teach you all the things you need to know. Continue reading to learn how to use a thickness planer efficiently and safely.

How to Use a Thickness Planer

Let’s jump right in.

Step 1: Choose the Right Thickness Planer

Your main choices here include benchtop thickness planers and full-size planers designed for large stock. If you just need a planer for basic use, a smaller benchtop model will probably do just fine, as these can usually accept boards up to 12 or even 15 inches in width.

All planers function in virtually the same way, with the only major difference being the size of stock that they can accept. Once you have chosen your planer, you can then move onto setting it up in your shop.

If you need some help choosing, make sure to check my recommendations.

Thickness Planer

Step 2: Set Up Your Tool

Now that you have chosen your thickness planer, the next step is to set it up in the right location within your shop.

First off, choose a good location, which means being somewhere near a power source, so you don’t need to run an extension cable across your shop, which can end up getting in the way. Next, be sure to choose a spot where you will have enough space for the infeed and the outfeed, so you can actually insert and remove wood without hitting a wall.

Finally, make sure that you set your planer up on top of a secure worktable, something that is not going to shake or move around as you plane wood. Secure the planer to the worktable using the manufacturer’s instructions on how to do so with your specific machine. It will usually be done either with clamps or a series of screws.

Step 3: Select the Material to be Planed

With your thickness planer set up, you can now get to choose the specific wood that you want to plane. Remember to keep the limits of your specific planer in mind. Generally speaking, you want to plane wood that is no less than 12 or 14 inches long, and no thinner than 3/4-inch.

Exactly how short and thin a piece can be before it is planed depends on the specific machine. That said, there are some workarounds that can allow you to plane excessively short or thin pieces. More about those later, though.

The other thing that is very important to know here is that thickness planers require one side of the wood to already be flat, as a planer can only plane the surface of wood relative to the other side. This means that if the bottom side of the wood being planed, the side that will make contact with the bed or table, is not flat, then the planer will maintain this unevenness when planning. You could actually make wood more uneven.

Therefore, before you plane a piece of wood, you first need to ensure that one side is perfectly flat, so it will rest evenly on the bed or table, thus allowing the planer to match that evenness on the topside. In order to flatten out one side of the wood, to make it even enough to be planed, you can use a jointer.

Seeing as most boards will first need to be run through the jointer before they can be planed, if you are serious about woodworking, you will need both a thickness planer and a jointer.

Step 4: Set the Thickness and the Depth Stop

One of the most important steps to get right here is to properly set the depth on your planer. This will determine how much is planed off. Now, there are some planers that may allow you to set the depth in terms of how much wood is being planed off. In other words, some planers may allow you to set the depth of the cut.

However, this method is quite complicated, so we would not recommend buying a planer that operates in this manner. For the most part, thickness planers will allow you to set the depth in terms of how thick the wood is being planed to.

For instance, you can set the thickness to 1-1/2 inches, and the planer will plane the wood down to that exact size. Some planers have a lever, some have a slide lever, and some have a crank that can be turned. Whatever the method of adjustment on your planer is, now is the time to set the depth according to what your final result needs to look like.

If you have a thickness planer that also has a depth stop function, now is the time to set the depth stop. This stops the thickness planer from planing any deeper than the depth stop is set to. You can always set the depth stop to a very low level in order to render it irrelevant. Remember, you don’t have to use a depth stop.

Thickness Planer Depth Stop

Step 5: Pass Your Board Through the Planer

With everything properly set up, you can now turn the planer on. Wait for it to get up to speed. This should take mere milliseconds. With the planer on and the parts in motion (rollers and cutters). You can now feed the wood through.

Make sure that the board is parallel to the right and left walls of the planer, and then feed it through in a very slow and controlled motion. Remember to always have your planer cutting along the grain of the wood, not against it, or else you might suffer from tear-out. You may need to do a few passes and make minor adjustments to achieve the desired results.

Moreover, something you want to avoid is snipe, which is when the edges of the wood get cut slightly deeper than the middle. To avoid this, when feeding the wood into the planer, slightly pull up or raise the back end, and as it comes out of the planer at the outfeed, slightly pull up on the front end. This will cause the cutter heads to even cut the middle and edges of the board.

The Basics of Thickness Planer Safety

To help keep you as safe as humanly possible, let’s go over all of the necessary wood planing safety tips to keep your fingers intact:

  • Never get your fingers close to the rollers or cutters. If you happen to get caught, your fingers, hands, and arms can get pulled into the planer. Instead, if you need to feed something through the planer, always use a push stick to create distance between your digits and those blades.
  • Never have long hair that is not tied up, never wear gloves, and never have long sleeves, jewelry, or anything else of the sort. Anything that hangs loosely off your body puts you at risk of being pulled into the planer.
  • That said, some things that you do want to wear when using a thickness planer are safety goggles, earplugs, and a respirator mask (if necessary).
  • Never raise or lower the table, or make any other sort of adjustment while there is stock on the table or while the machine is running.
  • Always use the appropriate dust extraction tools in order to remove sawdust from the area. If sawdust clogs up the machine, that can be dangerous, not to mention that having sawdust flying around will also obscure your vision.
  • Do not try to plane too much off at once, especially no more than 1/8-inch at a time. This can be very dangerous.

Thickness Planer in Use

Mistakes to Avoid

Lastly, let’s quickly talk about the biggest mistakes that you need to avoid when using a thickness planer for wood:

  • Never plane wood against the grain, or else it will cause tear-out.
  • If planing a short piece, never do so without attaching it to a second piece to allow for proper functioning of the machine.
  • Never plane more than 1/8-inch at a time, or else it may cause tear-out, or even worse.
  • Unless otherwise stated by your specific machine, do not plane wood that is less than 3/4-inch thick.
  • Never put wood in the planer before it has been turned on.

Once you’re done with reading this article, also check my tips and tricks for using a thickness planer.


There you have it folks, everything that you need to know about how to use a thickness planer safely. Just keep all of our safety tips in mind to keep yourself from suffering injuries, and you should be fine. After all, the planing process is fairly easy.

The one thing to keep in mind, though, is that a planer will “copy” the shape of your board’s other side. As such, if you run a board that is uneven at its bottom through the machine, the top will be uneven too. To avoid that, you will first need to ensure that the bottom is perfectly flat. One of the easiest ways to do so is to use a jointer.

In fact, there are even planer/jointer combo machines that can take care of these two tasks without you having to spend the money on or use the space for two separate machines.