How hard is MDF on blades &/or bits?

[Rich Engelhardt]

I have a project coming up shortly.
It involves making some faux wainscot.

I don't want to use MDF to save a few pennies only to find out I ruined a good track saw blade and/or a good Whiteside router bit.

[Mike Henderson]

I don't do a lot with MDF but haven't noticed any problems with it dulling my blades.

Mike

[Patrick Walsh]

I use it everyday and it destroys blades and bits..

Well just dulls them quick Nd then they need sharpening.

So no major problem just plan to sharpen often..

[Leo Graywacz]

Yup. It dulls them pretty quick. But you can keep using them on MDF for quite some time because it's a soft material. Particleboard or melamine are harder on cutters than MDF is. Like Patrick said, just plan on sharpening it after the job, price it in.

When I do painted wainscoting I use MDF for the panels but not the stiles and rails or cap molding. To soft for something that'll be bumped often. The face of MDF is hard, the edges or milled areas are considerable softer.

[Orlando Gonzalez]

Like the other gentlemen have said, MDF will dull them pretty quick. This is why I have what I consider throwaway (Woodline, MLCS, Craftsman, and the Chinese imports you can find on Amazon) bits for MDF and plywood. They are less expensive than a good premium bit and/or blade. I have Whiteside, CMT, Infinity, Amana, Onsrud, and some Freud as my premium bits.

[Mel Fulks]

To keep sharp longer : cut as fast as you safely can. Many ,especially beginners ,think slow is better for sharp. NO!
EXTRA slow is a real edge killer.

[Edwin Santos]

Yup. It dulls them pretty quick. But you can keep using them on MDF for quite some time because it's a soft material.

I've found it counter-intuitive that a soft composite material like MDF can be harder on carbide blades than natural wood. I guess it must be because the slurry of dust and glue they use to make it must be abrasive. Either way, I have never thought MDF would be harder on blades than say Baltic Birch plywood which has super hard glue lines and lots of them.

[Frank Pratt]

The resins that bind the wood fibers in MDF are what make it hard on edges. High speed steel will dull quickly with MDF. In fact, an HSS router bit will be lucky to make it more that a few feet before dulling to the point where it burns.

Like Edwin said, Baltic Birch glue lines are real killers. I one ruined a set of jointer knives by edge jointing a piece of 18 mm BB that was only about 4' long :(

[John Sincerbeaux]

The only good thing about MDF is for veneering substrates.
Other than that, MDF is the devil’s wood!
Kills blades, and YOU.... that fine powdery dust that goes everywhere is a known carcinogen.

[Rich Engelhardt]

Kills blades, and YOU.... that fine powdery dust that goes everywhere is a known carcinogen.hmmm - good to know. I suffer from COPD & have been on a real see saw battle with it the last few years. I may have to rethink this whole thing before I start it.

[Robert Engel]

Rich,

Please, if you have COPD avoid MDF completely. The dust goes straight to the lungs.

We think we're ok because we vaccum it up, use dust collection, air cleaners, etc, but the dust covers every horizontal surface in your shop & the particles are so small you won't notice, but every time air moves there is a little cloud of dust suspended in the air.

The only way I would say do it is outside the shop using a track saw.

[Chris Montoya]

Like what's been said already it will dull your blades fast. That isn't as much of an issue for me than the mess you end up with after cutting. MDF dust everywhere. Make sure if you go the rout of MDF to wear a good respirator.

Good luck

[Rich Engelhardt]

Robert - Agreed - if I do go this route, I can do all the cutting & routing outside.

[Yonak Hawkins]

I don't have any empirical evidence to disagree with anybody but, I've never sharpened or replaced the router bits on routers that are dedicated to MDF work over the course of many years and thousands of cuts. This may be due to the fact that cuts are not especially keen to begin with due to the nature of the material.

[Leo Graywacz]

Have you used those bits on Hard Maple to see if they'll cut or burn?

[Yonak Hawkins]

Have you used those bits on Hard Maple to see if they'll cut or burn?

No, they're dedicated strictly on MDF routers. They seem to cut MDF fine. That's all they're expected to do. I'm using one in my avatar pic.

[Leo Graywacz]

It'll cut MDF all day long, MDF is pretty soft. But you do lose that sharp definition when the cutter is actually sharp. I use double refined MDF for panels in my painted doors and I put a bevel on them so they fit in the slot nicely. It'll eat up the carbide after a while and you can see it in a pc of maple or other solid wood when you switch over. It'll actually leave a small hump, sometimes slightly burned because the carbide has been rounded over by the MDF.

When I was working for others I would make raised panels out of MDF. I would use the saw to score the MDF where the panel had it's shoulder. I noticed that the carbide would actually get chipped because the MDF was so hard on it. I got reprimanded by my boss for "wasting time" by doing the saw cut.

Then I went on vacation and he took over my position for the week. He apologized to me because he saw how the MDF damaged the carbide first hand. Told me to carry on.