What Is A Planer Woodworking Tool Used For – Transforming Rough Sawn
A woodworking planer is a power tool used to make rough, uneven, or warped boards a consistent thickness from end to end. Its primary job is called “thicknessing.”
It does not flatten a board on its own. To get a perfectly flat and square board, you must first use a jointer to create one flat reference face, which then rides on the planer’s bed to make the opposite face perfectly parallel.
Ever grab a stack of lumber from a big-box store or a local sawmill, excited to start a new project, only to find the boards are cupped, twisted, or all slightly different thicknesses? It’s a common frustration that can stop a project in its tracks.
You try to join two pieces, but there’s a gap. You run a board through the table saw, and it binds. Your final project looks… well, a little less than professional. We’ve all been there.
I promise you, there is a tool that solves this exact problem, and it’s a cornerstone of nearly every serious woodshop. It’s the key to unlocking the true potential of raw lumber and taking your projects from “homemade” to “handmade.” That tool is the thickness planer.
In this complete what is a planer woodworking tool used for guide, we’re going to demystify this essential machine. We’ll cover what it is, its core functions, how to use it safely, and how it works with its partner-in-crime, the jointer, to produce perfectly milled lumber for any project you can dream up.
So, What Exactly is a Woodworking Planer? (And What It’s NOT)
At its heart, a thickness planer is a surprisingly simple machine with one main job: to make the top face of a board perfectly parallel to the bottom face, bringing the board to a consistent thickness along its entire length.
Imagine feeding a lumpy, uneven slice of bread into a machine that shaves the top perfectly flat and smooth, making it the exact same thickness everywhere. That’s what a planer does for wood.
The Anatomy of a Thickness Planer
Most planers, whether they’re smaller benchtop models or large stationary machines, share a few key components:
- Cutterhead: This is the spinning heart of the machine, holding a set of sharp knives that shave off thin layers of wood.
- Infeed and Outfeed Rollers: These powered rollers grab the board and pull it through the machine at a consistent speed.
- Bed: A flat, smooth cast-iron or steel surface that the board slides across.
- Depth Adjustment Crank: A handle (usually on top) that raises or lowers the cutterhead assembly to set the final thickness of the board.
Planer vs. Jointer: A Critical Distinction
This is the single most important concept to grasp. A planer does not flatten wood. If you feed a warped board into a planer, you will get a thinner, but still warped, board out the other side.
The planer’s rollers press down on the warped board, temporarily flexing it flat against the bed. The cutterhead then shaves the top parallel to the bed. But as soon as the board exits, it springs back into its warped shape.
The jointer is the tool used to create the first, truly flat reference face. Once you have one flat face, you can place that face down on the planer’s bed. The planer will then make the top face perfectly parallel to that flat bottom face. They are a team, and one without the other is only half the solution.
The Core Purpose: What is a Planer Woodworking Tool Used For?
Now that we know how it works, let’s explore the primary jobs a planer handles in the workshop. Understanding the benefits of what is a planer woodworking tool used for will show you why it’s such a game-changing tool for any woodworker.
- Creating Consistent Thickness (Thicknessing): This is its number one job. For projects like cutting boards, cabinet doors, or tabletops where multiple boards are joined edge-to-edge, having every piece be the exact same thickness is non-negotiable for a seamless, professional result.
- Smoothing Rough Sawn Lumber: A planer is your gateway to using beautiful, less-expensive rough sawn lumber directly from a sawmill. It quickly shaves off the rough, fuzzy exterior to reveal the clean, smooth wood grain beneath.
- Milling Custom-Sized Stock: Need a board that is exactly 5/8″ thick for a specific design? You won’t find that at a home center. A planer gives you the power to create wood of any thickness you require, opening up endless design possibilities.
- Reclaiming and Re-sawing Wood: Found some beautiful old barn wood or want to re-saw a thick slab into thinner boards? A planer cleans up the aged surfaces and brings re-sawn pieces to a uniform, usable thickness.
How to Use a Planer: A Step-by-Step Guide for Beginners
Ready to turn a rough piece of lumber into a perfect project component? Let’s walk through the process. This section covers how to what is a planer woodworking tool used for safely and effectively.
- Safety First: Before you even plug it in, put on your safety gear. This means safety glasses are mandatory, and hearing protection is highly recommended. Planers are loud!
- Inspect Your Board: Carefully check your lumber for any embedded metal like nails, staples, or screws. Hitting metal will instantly destroy your planer knives. Also, avoid boards with large, loose knots that could dislodge.
- Establish One Flat Face: As we discussed, you must start with one perfectly flat reference face. Use a jointer (or a router sled for wider boards) to achieve this. Mark this flat face with a pencil squiggle.
- Set the Planer Depth: Place the board on the planer bed with the flat, jointed face down. Lower the cutterhead until it just touches the highest point of the board. Now, raise it slightly and remove the board. Turn the crank to lower the cutterhead by about half a turn (usually 1/16 of an inch) for your first pass.
- Feed the Board Correctly: Turn the planer on and let it get to full speed. Feed the board into the infeed side, keeping it straight. Let the rollers grab it and pull it through. Do not push it. Walk to the outfeed side to support the board as it exits to prevent it from tipping.
- Make Multiple Passes: Never try to remove too much wood at once. This stresses the motor and can cause tear-out. Make several shallow passes, lowering the cutterhead by 1/16″ or even 1/32″ at a time, until you reach your desired final thickness.
- Check Your Progress: Use a pair of digital calipers to check the thickness at several points along the board to ensure it’s consistent.
The Jointer + Planer Partnership: The Secret to Perfectly Square Stock
To get wood that is truly flat on all four sides—a state known as S4S (Surfaced Four Sides)—you need to follow a specific sequence using both a jointer and a planer (and a table saw). This is a foundational skill in fine woodworking.
Step 1: Face Jointing. Run one face of the board over the jointer until it is perfectly flat. This becomes Face #1.
Step 2: Edge Jointing. Place Face #1 firmly against the jointer’s fence and run an adjacent edge over the jointer until it is perfectly flat and 90 degrees to Face #1. This is Edge #2.
Step 3: Planing to Thickness. Take the board to your planer. Place Face #1 down on the planer bed and plane the opposite face (Face #3) until it is parallel and you’ve reached your final thickness.
Step 4: Ripping to Width. Finally, take the board to your table saw. Place Edge #2 against the table saw fence and rip the opposite edge (Edge #4) to its final width.
Following this four-step process will give you a board that is flat, square, and dimensionally perfect every time.
Common Problems with Planers and How to Fix Them
Even with the best technique, you’ll eventually run into some issues. Here are some of the most common problems with what is a planer woodworking tool used for and how to solve them.
Dealing with “Snipe”
Snipe is the term for when a planer cuts a little deeper at the very beginning and end of a board. It’s caused by the board tipping slightly as it enters and leaves the machine, engaging only one roller at a time.
How to Fix It: The best way is to support the board, keeping it level with the bed as it enters and exits. You can also feed a sacrificial piece of scrap wood of the same thickness immediately before and after your workpiece, so the snipe happens on the scrap instead.
Preventing Tear-Out
Tear-out happens when the cutterhead knives lift and tear the wood grain instead of shearing it cleanly, leaving a rough, chipped surface. This is common in wood with figured or reversing grain, like curly maple.
How to Fix It: First, try to feed the board so the knives are cutting “downhill” with the grain. Taking much lighter passes (1/32″ or less) also helps significantly. For very stubborn woods, lightly spritzing the surface with water can soften the fibers and lead to a cleaner cut.
Lines or Ridges on Your Board
If you see thin, raised lines running the length of your planed board, it’s almost always a sign of a nick in one of your planer knives. A piece of grit or a hard knot can easily cause this.
How to Fix It: The only real solution is to rotate or replace your knives. Most modern benchtop planers use double-sided, disposable knives, so you can often just unscrew them, flip them to the fresh edge, and reinstall them.
Best Practices for Planer Safety and Maintenance
A planer is a powerful tool and demands respect. Following these what is a planer woodworking tool used for best practices and this simple what is a planer woodworking tool used for care guide will keep both you and your machine in good shape.
Essential Safety Rules
- Never put your fingers near the infeed or outfeed openings while the machine is running.
- Never plane a board that is shorter than the distance between the infeed and outfeed rollers (usually around 12-14 inches). It can get kicked back.
- Always disconnect the power before performing any maintenance, like changing knives.
- Stand to the side of the machine when feeding stock, not directly behind it.
A Simple Planer Care Guide
- Wax the Bed: Regularly apply a coat of paste wax to the planer bed. This reduces friction and helps boards slide through smoothly.
- Clean the Rollers: Sawdust and pitch can build up on the rollers, causing them to slip. Clean them periodically with a cloth and mineral spirits.
- Check Your Knives: Dull knives tear wood and strain the motor. Inspect them regularly for nicks and sharpness. Replace or rotate them when they no longer produce a clean cut.
Sustainable Woodworking: An Eco-Friendly Approach to Planing
A planer can also be a key tool for more sustainable what is a planer woodworking tool used for practices. By allowing you to use raw and reclaimed materials, you reduce waste and your environmental footprint.
Instead of buying pre-milled lumber that has been transported across the country, you can source lumber from local sawyers or even from fallen trees in your area. A planer is the tool that makes this local, eco-friendly what is a planer woodworking tool used for approach possible.
Furthermore, don’t just throw away those beautiful wood shavings! They make excellent compost bulking material, animal bedding, or natural fire starters.
Frequently Asked Questions About Using a Woodworking Planer
Can a planer flatten a warped board?
No. A planer will only make a warped board into a thinner warped board. You need a jointer or a router sled to create one flat reference face first. The planer then makes the second face parallel to the first.
How much wood should I remove in one pass?
For most benchtop planers, a good rule of thumb is no more than 1/16″ per pass on boards up to 6 inches wide. For wider boards or very hard woods like maple, reduce that to 1/32″ per pass to avoid straining the motor and causing tear-out.
Do I need a planer if I buy S4S lumber from a store?
Not necessarily for basic projects. However, “S4S” lumber is often not perfectly flat or consistent. A planer gives you complete control, allows you to hit precise custom thicknesses, and lets you buy much cheaper rough sawn lumber, paying for itself over time.
What’s the difference between a planer and a hand plane?
A power thickness planer is a specialized machine for rapidly dimensioning lumber to a consistent thickness. A hand plane is a versatile hand tool used for flattening, smoothing, and fine-tuning surfaces by hand. They serve different, though sometimes overlapping, purposes.
The thickness planer is truly a gateway tool. It’s the machine that separates woodworkers who are limited by the dimensions of store-bought lumber from those who can shape and refine any piece of wood to their exact specifications.
It’s an investment, but the control, precision, and quality it brings to your work are invaluable. By understanding what a planer is used for and how to operate it safely, you’ve taken a massive step toward building more ambitious and beautiful projects.
Now, go find some rough lumber, fire up your tools safely, and start making something amazing. Happy woodworking!
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