MDF (medium-density fiberboard) is a versatile material. But cutting it can be a challenge. You may wonder and rightly so, whether you can plane MDF. There are a few conditions attached to this theory.
Can you plane MDF? Yes, you can plane it with a machine or hand plane, and you will get varying results. There are some downsides to planing MDF which is that it can be detrimental to your cutting blades. The glue content of MDF causes cutters or blades to become dull.
Background
We use a hand planer to reduce wood thickness and also make the surface smooth. It is the traditional method of processing wood, but one of the most effective as it gradually takes off the wood layers in a controlled manner.
Although we mostly associate planing wood with natural wood, the question often arises whether you can do the same with MDF. It will surprise you that you CAN plane MDF with a planer just like you do for natural wood but you may not get as good results.
If you need engineered wood of a particular thickness, you may look for it in MDF. Planing MDF to the desired thickness can be challenging. A more practical solution would be to procure plywood of the required thickness.
But what if you cannot get the exact thickness you want in plywood? In such a case, planing MDF can solve your problem.
Planing MDF can perhaps solve the problem, but you might face multiple issues. Firstly, the glues that go into the manufacturing of MDF are hard and can have a blunting effect on your cutting blades. You will need to resharpen them frequently or even replace them.
The Hazards of MDF Dust
Instead of chips, your planer will produce fine dust from MDF. This fine dust is hazardous, especially because it is likely to contain formaldehyde, a chemical added during the manufacturing process.
The dust also clogs the planer and it will stop working effectively. You can reduce this effect by blowing high-pressure air on the job from an air compressor. But you will also create clouds of MDF dust which can be hazardous unless you wear a respirator mask.
As we mentioned above, there’s nothing like buying MDF of the exact thickness and getting to work with it as soon as it hits your woodworking workshop. But if you don’t get the exact thickness, you will have to reduce the thickness yourself.
To reduce the thickness of an MDF board, you can use a hand planer or better still, use a drum sander with 150-grit sandpaper. The process will be tedious but you can perform the task much faster if you use a drum sander.
Precautions for Planing MDF
It is possible to plane MDF and many woodworkers do it regularly, especially for small sections. One woodworker reported that they could use an electric planer to plane MDF for more than a week without having to rotate or replace the sanding disk. However, there are hazards that you need to consider as mentioned below:
Urea-formaldehyde Content
These two toxic compounds are present in MDF. They are sealed in the boards before cutting. But once you apply a blade to the material through cutting or planing, these substances get released into the atmosphere carried by chips and powder.
Urea and formaldehyde are carcinogenic substances, so ensure to wear a respirator while working on this material.
MDF dust can also be hazardous if exposed to your skin, so wear gloves while handling this material.
To reduce the dust contamination in the environment, install a dust collection system in your woodworking shop. Ensure that it is working properly before you start working on the MDF.
Wear woodworker’s aprons and ensure that your arms are also covered, to avoid getting exposed to the dust.
Now you have all your safety precautions in place, you can proceed to work on planing your MDF!
Water Absorbency of Planed MDF
MDF boards from the factory come with highly polished and buffed surfaces. It provides a certain level of resistance to water. When you plane the surface, you expose the rather porous and fibrous interior.
The material becomes super water-absorbent, and you’ll even have a difficult time adding liquid finishes to it. So, if you’ve planed the top surface of MDF, you should avoid exposing it to moisture. It is better if you plane the sides of the boards.
What we have discussed so far concludes that yes, you can plane MDF, but you would be best off doing edge-planing for this material and that too, with extreme precautions.
You can plane table joints and other small sections, but with big furniture, you may have to reconsider your strategy.
Planing an MDF Door
In line with what we have discussed so far, we now know that you can edge-plane MDF with considerable ease. So, yes, edge-planing an MDF door is definitely on the books.
To make your job easier, you can use an electric planer, especially when the amount of material you need to take off is more than one millimeter. If you need to take off more than that (say, three to four millimeters), you can use a jigsaw or circular saw with satisfactory results and finish the job with your electric planer.
Running MDF Through a Jointer
You can use a jointer (or jointer-planer, surface planer, or planer) to machine MDF. But you’ll have to take all the usual safety precautions. Also, you may face issues with the cutting blades.
The cutting blades of your jointer are likely to get blunt more frequently. You will probably have to replace them earlier than usual. This can be a bit of a tedious operation because changing jointer blades aren’t that straightforward.
Purchasing high-quality blades for your jointer is a good option if you expect to be using it to process MDF. It will save you from having to change the jointer blades that frequently.
MDF Cutting Care
When you cut MDF boards rather than plane them, you will face fewer issues than when you want to plane or sand them. People cutting MDF boards simply cut the sheets through the edges.
Since the blades are hitting the board at right angles and the area of contact is less, the cutting is rather straightforward and there is less potential for raising hazardous MDF dust. Of course, there will be some but it will be significantly less than if you were planing or sanding the boards on their flat surfaces.
MDF has no wood grain – it has a homogenous structure. It makes it an easy material to cut, even easier than plywood which is more likely to chip at the edges.
Once the MDF has been cut into sections, you can easily trim it off with the help of a jigsaw or circular blade. But be aware that whenever you apply a cutting blade to MDF the glue in the material WILL have a blunting effect to it.
Conclusion
As we come to an end of this discussion, we can confirm that yes, you can plane MDF. However, planing the flat surface of MDF boards is not the most advisable thing to do – you are best off planing it at the edges.
The two takeaways here are first, you need to take adequate safety precautions while planing MDF. Secondly, the glue in the material has a dulling effect on cutting blades, so you need to use good quality blades, but will still end up sharpening them more frequently.
With these considerations in mind, you can use MDF in your woodworking projects and get some great results.
