The difference between MDF and Masonite
 

Can you tell me the difference between MDF (medium density fiberboard) and Masonite?

As I understand it, MDF is slwoly replacing Masonite, which I have painted on for a few years now. I would like to know what, if any, are the differences, and whether they are significant.

As far as I know Masonite is just a brand name for one company that makes (or made?) Medium Density Fiberboard.

Here is a site that has some interesting info on the various varieties of boards: wood panel glossary

Great question!

I just built a house, and we used some MDF.

My basic conception of it is that Masonite is a very hard board made of cellulose fibers and glue. Tempered Masonite is very hard and almost glossy on one side. Untempered Masonite is more porous on the flat side, not as glossy, but still pretty hard.

MDF, while made a similar way, isn't as dense throughout as Masonite, and generally has a separate "skin" laminated to it all around. It comes in boards and sheets. I don't know if you can get MDF as thin as a quarter- or eighth-inch sheet, like the Masonite.

MDF works up very well, and takes paint well, and it is uniform throughout and isn't supposed to warp. But it is bloody heavy compared to wood or Masonite, in spite of its name. It's great for shelves.

Michele is right in that Masonite is a brand of hardboard, and MDF is a generic term for Medium Density Fiberboard.

We also used something called MDO (Medium Density Overlay) in the bathroom, which is supposed to be more waterproof. But I can't really tell you the difference in how it's made.

The guys at a good building supply dealership could probably make this a lot simpler explanation than I have.

A little knowledge....as they say.

Richard,

I used 3/4" inch thick MDF in college; I had Home Depot cut the huge sheet into 8"x10" panels. I ended up with a zillion (I can't remember exactly how many) panels for less than $20.

Post # 6 by Sharon Knettel in this thread explains the difference between MDF and Masonite:
MDF (Medium Density Fiberboard) for large art panels

I really liked using it; the only caution I have is that if an unprimed panel gets wet or if a corner gets dinged, the layers can start peeling apart.

Anna