A jointer is a woodworking machine that flattens, smoothes, and levels wooden workpieces. It slices the uneven parts of the wood linearly fed to it using a rotating cutter that sits between two tables. It prepares rough or uneven lumber for furniture, cabinetry, and other woodworking projects.
But how exactly does a jointer work? What are the different types of jointers? And what is the difference between a jointer and a planar?
This article discusses jointers by explaining various types of jointers, their working, and applications, and compares them with planers.
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What is a Jointer? Explained
A jointer is a machine that performs the same job as a jointer plane without needing you to apply force by hand.
Its primary function is to level and flatten wooden workpieces so they can be used as butt joints, panels, or boards in furniture and cabinetry projects.
It can also remove imperfections like warping and cupping. Four main components of the jointer, i.e., the infeed table, outfeed table, fence, and cutter head, help it work efficiently.
How Does a Jointer Work? Explained
Preparation of surface
Begin by cutting your wooden workpiece into smaller pieces that will be easier to joint and meet your project requirements.
Make sure the surface is relatively smooth and even, and use a jointer plane to make it smoother before you begin jointing.
Remove hard protrusions like nails or metal from the surface. Otherwise, they can interfere with the jointing process.
Ensure the workpiece surface is not too wet or greasy, as this can cause damage to the cutter teeth and make the surface uneven. The ideal surface should be completely dry.
Adjusting the depth of cut
Adjust the infeed table height to choose a suitable depth of cut as the outfeed table is fixed.
You can use the height scale, usually imprinted on the front surface, to help you adjust the height.
Be careful not to choose a high cut depth, as it can damage the cutter or the workpiece surface.
For best results, select an optimal cutting depth with a fair number of passes to ensure smooth and efficient material removal.
Feeding the workpiece
Once you switch on the jointer, move your workpiece across the cutter using the push pads.
To ensure the cutting efficacy and overall operation, it's best to test the jointer on a spare wooden piece first.
In case of cutting depth, you can usually aim for 1/32" and feed the workpiece a few times until the desired material is removed.
You can use a 1/8" cutting depth with carbide, titanium, or diamond teeth inserts if you need deeper cuts. You'll need more passes if the wooden plank is twisted or warped.
When passing the workpiece over the cutter, don't apply too much pressure, as this can cause vibrations and damage the machine.
Keep the feeding speed low, so each part of the workpiece is adequately exposed to the cutting action.
Most importantly, follow the grain structure of the workpiece's surface to prevent uneven chipping or surface damage.
Types of Jointers - What are they used for?
|Type of Jointer||Application|
|Jointer/planer combo||Bulk production in the furniture industry|
|Free-standing jointer||Carpentry and cabinetry applications|
|Benchtop/Hand-held power jointer||Medium-scale, personal, and small-scale woodworking application|
Jointer/planer combo machines are valuable tools for planning and jointing operations on a workpiece.
The cutting blades are adjustable, so the machine can also function as a planer.
These machines have a motor with a power of 1-2 HP, typically 10 Amps, and a minimum of 5000 RPM.
The cutting depth of these machines is usually between 1/8 and 1/16 of an inch.
All types of jointers should necessarily possess machine guards and a proper alarm system in case of malfunction.
This jointer category also has a damping system which helps extend its longevity. However, this machine is heavy and not very portable.
It is durable and convenient but more expensive than other types. It is commonly used to make furniture parts like panels and slabs in large quantities.
Free-standing jointers are large jointer machines that are not very portable but have a more advanced cutter unit.
The portability is low because it weighs less and is less durable than a jointer-planar combination machine.
They usually have a motor with less than 2 hp power and their cutting speed range from 2000 to 5000 RPM.
The cutting depth is the same as the jointer planer combination machine, but the vibration suppression system will not be as effective.
It has a larger frame and longer beds that are 6" or 8" wide, allowing you to work with bigger pieces.
Free-standing jointers are cheaper than the jointer/planar combo but more expensive than a benchtop or hand-held version.
It is often used in carpentry and cabinetry for preparing wooden doors, handles, and slabs.
Benchtop/Hand-held power jointer
Benchtop/Hand-held power jointers are the most affordable and portable jointer machines.
You can also adjust the blades of the machine to use it as a planer.
These jointers usually have a motor with less than 2 hp power and a speed ranging from 1000 to 5000 RPM.
Unfortunately, there is no vacuum suction system to reduce vibrations and clean the machine.
These models usually have a smaller frame and a cutting width of 6" or less, making them the best option for DIY projects, small-scale carpentry, and cabinetry applications like flattening wooden racks and panels.
Parts of a Jointer
The infeed and outfeed tables are coplanar, lying in the same plane.
An infeed table supports the workpiece as you move it towards the cutter head.
Its smooth steel surface makes it highly durable, and the low friction makes it easy to move the workpiece over the table.
The infeed and outfeed tables are positioned at slightly different heights, with the infeed table slightly lower than the outfeed table. This allows the cutter to remove material effectively.
You can adjust the height using a handle or handwheel on the infeed table, depending on the depth of cut you want to remove.
Collectively, the infeed and outfeed tables are referred to as a bed.
A rule of thumb is that a jointer can handle workpieces twice as long as its bed.
Thus, you can machine a larger wooden workpiece with an extended bed dimension.
The outfeed table supports the machined portion of your workpiece.
Its height is fixed concerning the infeed table and cutter head. The surface composition of the outfeed table is identical to the infeed table.
Once your workpiece is machined, it can be slid onto the outfeed table.
The jointer fence covers the length of both tables along their edges.
A fence is a slightly raised metal surface that ensures easy movement of the workpiece along the table while preventing it from sliding off.
Moreover, it provides a flat surface against which you can judge your workpiece's smoothness and flatness at the edges.
The cutter head is the most critical component of a jointer.
It comprises spiral-shaped teeth edges with some spacings in between to aid in material flow during removal.
The cutter is usually made up of high-speed steel. However, titanium or diamond inserts can be used for added durability and more efficient material removal.
It sits on a shaft driven by a motor with power ranging from 1 - 2 hp. In larger jointers, the motors used have a higher power rating.
The cutter teeth circumference is level with the upper surface of the outfeed table.
Jointer cutter heads usually have a depth of cut between 1/16" - 1/8".
The most commonly used jointer has a 6" long cutter head, which ultimately indicates that the maximum workpiece width it can manage is 6".
Machine guards covering the cutter head are necessary to protect the operator from injury.
They are attached to rotating joints that move the guard away, exposing the cutter teeth when you push it with the workpiece's leading surface.
The push pads have handles and a rubber contact surface, making it easy to move the wooden workpiece along the tables.
A vacuum suction system for cleaning the sawdust resulting from the jointing operation is ideal, as it sucks in all the sawdust and debris in and around the workspace.
Jointer vs Planer: When should you use them?
|Relatively less portable||Relatively more portable|
|Higher cutting efficiency||Lower cutting efficiency|
|Flattening mechanism||Uniform thickness mechanism|
|Cutter orientation vertical||Cutter orientation is vertical and horizontal|
A jointer can correct cups, bows, warps, and twists in lumber in addition to flattening it while a planer can only reduce the thickness of the lumber.
A planer is much more limited in application compared to a jointer.
If you don't want to invest in a jointer, the only other way to correct warped lumber in your shop is to build a complex jig for your table saw.
While benchtop jointers and benchtop planers are similarly priced, larger heavy jointers are much more expensive than planers.
Jointers use a single long spiral-shaped cutter to remove material on one side of the workpiece.
Whereas planers have cutting teeth on the top and bottom sides, some models even have teeth positioned sideways.
In terms of durability, both these machines are robust and long-lasting.
Overall, if you just want to reduce thickness, just get a planer, but to correct defects in the wood, you need a jointer.
When choosing a jointer for woodworking, it's important to consider your budget and needs.
A jointer-planar combination is an excellent option if money isn't an issue.
On the other hand, a hand-held jointer is a budget-friendly choice that can still get the job done.
Ultimately, jointers are essential for creating perfect pieces of furniture.
Frequently Asked Questions
What safety precautions should you take while performing jointing?
The safety precautions you must take while performing jointing include wearing a respirator, goggles, safety shoes, headgear, gloves, and a protective coat. Moreover, a dust collector should be installed on the jointer to clean up all the sawdust in the work area. A face shield can also provide additional security against flying debris.
What materials can undergo jointing?
What is a grain structure in woodworking?
A grain structure in woodworking is defined as the orientation, arrangement, and visual texture of the molecules in a wooden workpiece. You can clearly see the grain structure on a block of dry sanded wood.