Medium Density Fiberboard.

So, people either love it or hate it. I'm in the former camp. I really like MDF for many cabinet projects that will be painted or have a flux finish applied. The stuff is stable, flat, straight and relatively inexpensive to purchase. MDF comes in a couple of different forms, from 4x8 foot sheets to 5x12 foot sheets and thickness from 1/4" to 1-1/16". There is a "standard" product and there is a "light" weight product. The light weight product is about 30% lighter then the standard, but costs a bit more pre square foot. I try only to use the light weight product.

MDF's made from "stuff", but just exactly what stuff I'd be hard pressed to tell you. What it's made from is less important to me than how it performs, which is always the concern of the crafts person of woodworker. I'm sure it's made from wood by-products and glue and that's about all I can tell you. Will it kill you? Maybe, maybe not ;-).

I can tell you that it cuts great, takes and holds an edge well and is easy to put together. Where this stuff really shines is in it stability and flatness which makes it great for anything that needs to be painted. I've also stained the stuff with a wipe on gel stain and the project didn't look half bad. When you're working with MDF the first thing you will notice is that it cuts great, the second things is just how darn dusty it is. It does make a fair amount of dust, but no more then made when cutting mahogany. It will take and hold an edge, but does dull cutter quickly. The use of carbide cutters and a dust mask are high recommended when cutting.

As with most any "wood" that you cut you are bound to get saw marks and alike. The degree of these marks are a function of how well your machine is tuned, the quality of the blade you use and the precession of the hold of jig that you use to cut the product. Regardless, you will wind up with some marks and it is imperative to remove them all before for finishing.

I've found that sanding with 150 grit sand paper is just the right amount to remove all the marks from a piece of MDF. You must sand all "cut" or profiled edges. These edges have what can best be described as an open texture. It is this texture that you need to smooth and "fill". A fill can be a glue size, a paste filler or even good old shellac. Apply at least two coats to the machined edges sanding between coats and you should be good to go.

The better the job you do here filling and sanding the better the final product will look and feel. Once you sand all the edges, you can sand all the "flats" as well with the same 150 grit sand paper. It's important to sand the entire piece of MDF so you give it a uniformed surface. This will improve the way it takes the primer coat.

Once you've detailed and sanded all the pieces of MDF you can begin to apply your first primer coat. The photo to the right shows the drawer panels and door of a bathroom vanity I've been working on. They will be painted white with a water bourne pigmented lacquer from ML Campbell.

When you begin to prime, try and prime all the details first. The primer I used this time was Bin water bourne. I have used Bin pigmented white shellac in the past, but wanted to try out the Bin WB. It covered well, applied easily, dried relatively fast and was easy to sand. The end product looked and felt great.