Medium-density fiberboard (MDF) is an engineered wood often used for woodworking applications like cabinetry and furniture.
But can you plane MDF? And what factor should you consider?
Yes, MDF can be planed. However, the solid fibrous structure of MDF can prevent the planer from smoothly removing the shavings from the surface, causing the fibers to break and tear up, damaging the surface. Apart from that, it can also affect the tool's life by rendering the blade dull.
I tested this by planing MDF on my planer before writing this article.
This article provides a detailed guide on planing MDF by discussing the factors to consider when planing MDF and also provides some alternatives to planing MDF.
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Can you Plane MDF? Answered
While MDF can certainly be planed, planing MDF can be comparatively more challenging than planing plywood or other materials.
This is because of the dense, fibrous structure and presence of resin binder, which makes it difficult to remove the material from its surface.
Its high adhesive content and strongly interconnected wooden fibers make it challenging to plane MDF, damaging and dulling the planing blades over time.
Therefore, using inappropriate tools or performing the planing incorrectly can damage the surface of the MDF board, rendering it useless for the application.
Apart from that, the resin in MDF has urea formaldehyde, which is a toxic substance, and the dust produced during the planing of MDF can cause skin, eyes, and respiratory irritations.
Things to Consider When Planing MDF
There are a few important things you need to consider before planing MDF on your planer.
Hand Planing vs Power Planing
Hand planing involves using a manual hand plane, which is cheaper than a power planer but requires more effort and is time-consuming.
While a power planer can provide the ability to quickly plane the surface of MDF, a hand planer allows you to feel the feedback from the planing surface and adjust the planing force accordingly.
As a result, a hand planer minimizes the risk of damaging the MDF workpiece while planing.
Although MDF sheets generally have a smooth surface, if your application requires planing a large surface to reduce the thickness of the sheet it is advised to use a thickness planer.
However, when planing MDF, irrespective of the type of planer you use, maintain a shallow depth of cut to avoid ripping off the fibers and damaging the workpiece.
Blade Requirements for planing MDF
Always use a sharp blade for planing MDF to avoid damaging the surface.
Depending on user requirements, use a suitable blade angle, which will determine the cutting depth. For deeper cuts, use a higher blade angle and vice versa.
Ensure that the cutting depth is not too deep, as that may also damage the inner layers of the MDF and render the tool blades dull.
Clamping the Workpiece
Always ensure that the MDF workpiece is properly clamped onto the work table.
Proper fastening of the workpiece ensures minimal vibrations during planing, preventing the workpiece from damage and potential injury to the user.
After-affect of Planing MDF
Planing exposes pores and cavities within the MDF workpiece's layers, so before painting the surface, always use a primer to seal off these openings.
A minimum of two coats of paint are required after planing the MDF, as the first layer soaks down into the surface while the other adheres properly onto the surface, giving a uniform finish.
Generally, MDF has some water resistance and can withstand small amounts of water exposure without any significant damage.
However, planing the MDF exposes its pores, and any sort of exposure to water results in the seeping of moisture through these pores, damaging the MDF workpiece.
Planing is usually preferred to plane the edges or sides of the MDF workpiece, but if your application requires planing the face of a large MDF sheet, it is recommended to use an alternative tool.
To reduce the thickness of a large sheet, it is generally advised to use a cutting or sanding tool to remove the required amount of material, followed by a finishing process to enhance its surface quality.
Alternatives to Planing MDF
Generally, it is not required to plane the face of the MDF to reduce its thickness.
However, if the need arises, there are some alternative techniques that you can use to remove the required amount of material and then finish the surface as desired.
The sanding technique is a woodworking operation that utilizes sandpaper coupled with a rotary tool to smoothen and flatten the wooden surface.
However, sanding has a low material removal rate, and the material removed forms dust, which is hazardous to health.
As a result, it is important to wear a safety mask when sanding MDF.
The sandpaper coating on the sanding tool has a grit number that indicates the efficiency of material removal, with a high grit number being able to remove smaller-sized imperfections and vice versa.
Sanding is not ideal for reducing the workpiece thickness as it is slower due to a lower material removal rate. The tool itself will wear out when used for extended periods.
It is suitable for finishing operations where less than half an inch of material is to be removed.
For sanding large sheets of MDF, a drum sander, such as BOSCH ROS20VSC Palm Sander can be used, as that provides dust collection and variable speed control to attain desired finish.
You can also perform sanding manually by hand, but that is more time-consuming and demands more effort.
Power Cutting Tools
Any power tool, like a chainsaw, jigsaw blade, or circular blade, can also be used to reduce the thickness of an MDF workpiece.
However, these tools cannot provide the ability to remove very thin layers of material and the surface attained after cutting the workpiece will have a poor surface finish.
This technique can also penetrate deep into the MDF layers and damage them, along with tool blades.
It would be best if you marked a reference on the MDF workpiece along which the cutting operation is to be performed.
A post-processing technique, such as sanding, will be required to obtain a uniform surface.
This method is the fastest but provides less control and can be inconvenient to perform.
Manual Cutting Tools
You can use a manual cutting tool like a hacksaw as it is the cheapest and most straightforward method, especially from a hobbyist perspective.
Although it can be tedious and time-consuming to use a hand tool, it provides better control over the cutting process than a power tool.
A reference must also be marked on the MDF workpiece along which the user will perform the cutting operation.
The resulting surface will be non-uniform with a rugged feel and an untidy look. Cutting a significant thickness can also damage the deeper layers of MDF and the tool blades.
A secondary finishing process is also necessary here to properly finish the resulting surface.
Is Planing Wood easier than planing MDF?
The planing operation uses a sharp tool to remove long chips of wood from the wooden workpiece to reduce its thickness and attain a smooth surface finish.
Unlike MDF, wood is comparatively easier to plane as it has a uniform structure with grains aligned along a particular direction.
Therefore, planing wood along its grains results in smooth gliding of the planer along its surface to remove fine shavings of wood, producing the surface with desired surface finish.
A manual planer is suitable for planing small wooden workpieces, whereas an automatic planer is preferable for large-scale planing applications.
Before planing, it is important to ensure that the wooden workpiece has no potential protrusion on the surface, which may damage the planing tool.
Planing MDF can be difficult, but you can easily carry it out with the correct training and understanding of the process.
MDF has a fibrous structure with high density and random grain orientation. As a result, planing MDF can result in the clogging of fibers in the blade, damaging the cutting tool and the workpiece.
Apart from that, planing MDF can produce hazardous dust, making it important to wear a respiratory mask when planing or sanding MDF.
Therefore, if your application requires extensive planing, it is advised to opt for an alternative to MDF, such as softwood.
Frequently Asked Questions (FAQ)
Can you perform filing on MDF?
Yes, you can file MDF, but excessive filing will dull the blades of the hand file and can even damage the MDF surface.
Can MDF be used in high-load applications?
Yes, MDF can be used in high-load applications up to 35 pounds per square foot. Although durable, it can fracture when subjected to higher loads.
What are the safety precautions required during planing of MDF?
The safety precautions required during planing of MDF include wearing respirator masks, eye goggles, gloves, safety boots, and helmets. Additionally, a face shield is also ideal to use during this operation.
What is the grain structure in woodworking?
The grain structure in woodworking is defined as the molecular structure and orientation of the wooden fibers in a wooden workpiece. Generally, it is recommended to remove the material along the grain structure to attain a smooth surface finish.