Uses for MDF?

[Ralph Compton]

I have read various posts about what MDF is not good for. So, what IS it good for? Why is it made? Who uses it?

Jigs? Sleds? Boxes? Shelves? Cupboards? Cupboard doors?

Same thing re finishes for MDF.

Oil? Alcohol (shellac)? Water-based?

I recently made some utility boxes with it and was pleased with how easily it machined. First time I've used it. (Dust collection an absolute must.) I put them together with 18ga brads and glue with a shellac sealer. Seems OK now but will it fall apart or disintegrate in 6 months?

Minwax shows a video of putting gel stain on MDF so they must have some idea of how to seal it.

There must be some rationale for making the stuff unless the government is just subsidizing it like solar cells.

Ralph

[Stuart]

They make it because furniture companies like it. It's cheap, easily moulded into shapes which would otherwise require time and machinery to cut and fabricate, can be easily covered in a "foil" to make it look good and requires regular replacement.

[Larry Jaques]

No, use Baltic or Russian birch ply instead. Gluing and routing jigs are the exception.

Yes, cabinetry and speaker boxes.

Narrow shelves, as it won't support weight for long.

VERY low-rent.

Shellac or oil finishes preferred, IF you finish it.

Yes, use DC, but it's hell on bits. Dulls 'em quickly.

They don't like a lot of movement, so they don't make good travel chests. Brads to hold the glue until it sets is just fine. Biscuits are fine, too, usually with brads to...

It's cheap, flat, fairly strong, and easy to hide. People veneer it and laminate it, mostly. Reason for making it: To use up all that damned excess sawdust, of course.

-- In an industrial society which confuses work and productivity, the necessity of producing has always been an enemy of the desire to create. -- Raoul Vaneigem

[Swingman]

Bzzzzzt! Not true at ALL C-Less!

All mdf is not created equal and high quality mdf makes some of the best cabinet doors you can buy, and also some of the best interior doors for houses.

AAMOF, the dimensional stability of the product makes it superior for many of these applications, particularly where design spacing spec's must be met 24/7/365.

Jerk thyself into the 21st century! :)

[Larry Jaques]

I sit corrected, but the only ones I've seen were truly less than Sauder quality, more like _early_ particle board. =:0 Remember that gawdawful stuff? Three drops of water and you get instant delam a foot in diameter.

Yes, when kept dry, they're very stable.

Easily, old sport. I'm ambidextrous.

-- In an industrial society which confuses work and productivity, the necessity of producing has always been an enemy of the desire to create. -- Raoul Vaneigem

[Robatoy]

I used to buy HDF, high density fibre board. Considerably denser and able to make MUCH bigger dust storms. I had it laid up with a variety of veneers. Made very heavy/ acoustically dead boxes. My V-groove guy was able to cut exactly half- way through the veneer which ranged, depending on species from 1/32 to as much as .040 ( just a smidge over a mm.) Wonderful substrate.

[russellseaton1]

I made kitchen counter tops from MDF. Comes in 48-49-50 inch widths. Cut it in half roughly and you get double layers of counter top. Takes plastic laminate great. Contact cement sticks to it great. Cover the edges so water won't get to it and it should last for decades.

[Robatoy]

You have to apply a balance sheet. Have to.

[Leon]

Actually there is MDF that remains dimensionally stable when wet. I forget the technical name for it but it is referred to as water resistant MDF. The particular kind I am referring to is green, dollar bill green. Swingman and I recently built cabinets and doors for a kitchen remodel, the doors were this green MDF and we put a piece of the material 3/4x3/4x8" in a bird bath that had circulating water and left it to soak over night. The MDF did not change size or shape and the water did not wick.

[Swingman]

And that piece was unfinished ... after being primed and painted that particular material is at the top of the category of any other material suitable for cabinet doors in a _painted_ kitchen environment, and better than most for its dimensional stability and resistance to warping, shrinking and cracking.

Until the end of the first decade of the 21st century I was reluctant to even consider the use of composite material in a kitchen door, but times have changed, and so have the properties of the materials available.

The problems come, not from the material itself, but from reactions based on old experiences, ignorance of the properties of newer materials available, and an unwillingness to change with the times.

[Larry Jaques]

Amazing, but that material is certainly not the norm, nor is it reasonable in price, nor is it easily obtained locally.

-- In an industrial society which confuses work and productivity, the necessity of producing has always been an enemy of the desire to create. -- Raoul Vaneigem

[-MIKE-]

I remember an argument in here in which someone said they refused to use that horrible, cheap, new building material called, "plywood" as a subfloor, but would stick with the tried and true 6 and 8 inch wide floor boards which were so much stronger and more stable. :-)

[Swingman]

UltraStock: $32.95 (4 x 8x 3/4).

Heard tell right here the other day that Home Depot carries Temple-Inland's "UltraStock" (the green stuff Leon is talking about) in many locales. A hardwood plywood supplier/lumber yard should have it, or can get it.

[russellseaton1]

By balance sheet I assume you mean another layer of plastic laminate to the other side of the MDF. Would you? Assuming two layers of MDF,

1.5" thick. With plastic laminate on the top for the counter top. Would you put another layer of plastic laminate on the bottom?

[Doug Winterburn]

Depends on environment. My 5th wheel countertops are bowed up at the ends close to 1/4" over 7' meaning the 3/4' mdf substrate has expanded and the formica hasn't. Of course, the 5th wheel sits unheated and uncooled for weeks and sometimes months at a time. Even so, I am surprised as it mostly is stored in the Arizona desert environment. I think plywood would have been a better choice for a substrate in a RV - that's what I used in a house I built in Washington State and the countertops stayed flat.