has anyone else had problems with mdf?

[letterk]

I've used MDF for smaller modular shelf system. It's sturdy for the project I used it on. Plus, it was affordable, sanded easily and finished pretty nice. I did have to use nailer filler on the cut end so they didn't swell and have a different texture than the sides. That and pre-drill the nail holes. Cut end can absorb moisture so you have to make sure it is finished and a primer to seal before applying water-based paints.

Of course, I've now found a local lumber yard with good deals on 1/2 maple ply so I usually try to use it instead. If they ever get more Baltic Birch for cheap it would be my go to choice.

[dusty]

[quote="fjimp"]MDF and other related products were heavily used in my shop for jigs. In recent months I have found multiple situations where they have failed me. I built one replacement jig and will replace it when health situation allows. As to Baltic Birch for jigs]
Generally speaking, fasteners and MDF are incompatible.

If MDF parts can be held together with nuts and bolts AND it is sealed to protect it from moisture - it lasts forever (with one exception that I have experienced). Do not use it to support weight like in book shelves that house all of your Wood and Woodsmith magazines. The shelves, even if 1" MDF, will sag.

[wa2crk]

I have used MDF for some garage cabinets without any problems YET. For joining panels at right angles I use dado joints. The upright cabinets are 96" tall and are still OK after 6 years although they have been painted with a semi gloss latex paint.
The wall cabinets are unfinished but the edges of the shelves have to be supported by a solid piece of wood (in this case poplar) to accept the load.

[ATTACH]23807[/ATTACH]

The wall cabinets are attached to the concrete block using the French cleat method

[ATTACH]23808[/ATTACH]
Bill V

[dusty]

I have used MDF for some garage cabinets without any problems YET. For joining panels at right angles I use dado joints. The upright cabinets are 96" tall and are still OK after 6 years although they have been painted with a semi gloss latex paint.
The wall cabinets are unfinished but the edges of the shelves have to be supported by a solid piece of wood (in this case poplar) to accept the load.

[ATTACH]23807[/ATTACH]

The wall cabinets are attached to the concrete block using the French cleat method

[ATTACH]23808[/ATTACH]
Bill V

Really nice looking storage area. It looks great.

The load that you are putting on the shelves will probably not stress the shelves. Your storage containers help by distributing the weight toward the ends of the shelves.

[heathicus]

Like any other material, there are times when you should not use MDF, and times when it's perfectly okay. And there are ways you should and should not work with it.

It's definitely not made to be run through a planer or joiner. It's not a substitute for solid wood. It's basically very densely glued together sawdust sandwiched between two layers of paper. Buy the thickness you need. It's already very very flat, consistent, and stable.

Any edges exposed from sawing will soak up a LOT of glue. Don't rely on just glue when joining an edge. Use screws. And predrill and counter sink or bore as appropriate. The dowell trick that was suggested is something to keep in mind too.

It will sag and break easier than wood. Experiment with it and learn its limitations and capabilities, and it will be just fine.

[Ed in Tampa]

I personally like MDF although it is quickly becoming too heavy for me to horse around much longer. I can still pick up a full 3/4 inch thick sheet but I do grunt doing it.

Like anything you have to know it's positive qualities and negative qualities.
Just as you can't use oak for every project (oak doesn't last long buried in the ground) you can't use MDF always either.

I hear a lot of talk about it dulling cutting tools and it does. But so does everything else. Some of the this new plywood is some of the worst for dulling bits.

MDF can be made to look like most anything from felt to leather to high polished plastic. When protected it has reasonable resistance to moisture and it is dimensionally sable ( won't warp or expand and contract with humidity.)

It requires special handling when trying to connect it using end grain. And I have found that its strength (Sagwise) it is very similar to dimensional lumber

MDF Is often confused with particle board (junk in my opinion), strand board( even worst junk in my opinion) and hard board(very useful in my opinion). It is none of these.

If cost is a factor and it nearly always is I use MDF if it is going to be painted, ply if it isn't going to be painted or around moisture and solid wood when I see the green or momma says

MDF treated with Boiled Linseed or Tung oil make fantastic shop Jigs. I love it for that usage. MDF also make fantastic desk tops. MDF does not dent so there is no pencil imprints to deal with.

I screw MDF using dry wall type screws, or confirmat or the new screws out made exclusively for MDF (spax MDF screws). The Spax screw does not have to be predrilled.

I use regular glue and I like to use oil finish on MDF but I also simply paint it.
Use Flood floetrol mixed in your paint for a finish that looks sprayed on.

[wa2crk]

MDF does stay flat and when finished with a couple of coats of polyurethane it looks good too. My main bench top is two thicknesses of MDF and two thicknesses of MDF about 8" wide around the underside and then banded with some southern yellow pine. I added a router table top to one end.
The frame is also SYP. Not very expensive to build and is VERY heavy so it doesn't move when pushed on.


[ATTACH]23814[/ATTACH]

The plans were downloaded from the Woodsmithshop TV show
Bill V

[masonsailor2]

I have used it extensively in production cabinet work. If you are doing paint grade work it gives you a very stable and flat material to work with that paints easily and is very easy to shape. That being said it has some limitations that are difficult to deal with. It has very poor performance exposed to moisture and it probably should not be used in your shop unless you have very good dust collection ( i.e. commercial grade). The secret to MDF is the fastening systems. It is not as strong as conventional plywood but is actually quite adequate for most cabinet work. Biscuit joinery makes for fairly strong joints and the cam lock clamping system allows for very quick assembly using very few clamps. But all of this is irrelevant if you don't have the dust collection. The dust that stuff makes is not friendly to your lungs ! That was a beautiful job on that hutch. I would be interested in the painting technique. Very nice effects. How was that done ?
Paul