I had never even heard of MFD until I joined this forum. I still have never even seen this material, or at least I don't think that I have unless that stuff that is used to make furniture like that which you buy at Wal Mart such as computer desks. I had always referred to that stuff as fiber board or press board and certainly have not been impressed with it. I have a feeling however that stuff is not MFD. Will somebody give me a little low down on MFD as to its qualiity, and what or where is it commonly used, and its cost compared to hardwood.

Thanks,

Jerry

Medium Density Fiberboard- made from wood fibers, wax and resins, heated up and pressed into form. Very dense. Said to be stronger than particle board... I don't feel it is stronger than plywood, especially laid on it's side. Both particle board, melamine and mdf tend to want to sag on me when I try to use them on their side, unless (now) I double the thickness. Maybe it was just my experience, but I hated having to replace them when they did and I don't want to "eat" that mistake again.

It is very consistently flat and easily machinable. Great for interior paint out kinds of work. Emits "LOTS" of dust when machined. It has materials and some byproducts in the wood fiber and the resins that makes blades and cutting edges not want to stay sharp as long. Easy and fast to sand (again lots of dust) which again makes work flow fast.

Because of it's machineability and being able to retain details and a fine edge, you can create a quality high-end looking paint-out piece of work very quickly.

I feel that pilot holes are required (not just recommended) for screws or else it will split. You can use sheet metal screws (preferred), but they need to be course thread. Fine threads tend to want to strip. I start a screw... It will pull up a small edge because of swelling from that surface compression, remove the screw, knock that edge off with a sharp putty knife or chisel, then re-screw it in to depth and it's fine. Grain seems like it is between the flat sides, so that tendency to split is worse when putting screws in it's edges.

Finish nails in it does fine.

It doesn't handle water very well and tends to swell if exposed. It also is not real durable. Corners and edges have a tendency to dent and wear faster than wood.

Glues together great, because it soaks in evenly. Painting, I start with a primer coat to seal.

I guess that's a good start on info for you, from what I can remember at the moment...

 

MDF doesn't handle water very well and tends to SWELL...

...It doesn't handle water very well and tends to swell if exposed. It also is not real durable. Corners and edges have a tendency to dent and wear faster than wood...

If you do add water, check out a possible result:

http://www.routerforums.com/lobby/38136-particle-board-desks-can-problem.html

 

Are you referring to MDF, as opposed to MFD?
MDF is Medium Density Fiberboard. It's an engineered product made of compressed wood fibers (more like sawdust) and resins.
You can find it it 1/4", 1/2", 3/4" and, thicker. The thicker, 1" and above, are not usually available at your big box stores or the local lumber yard. At least in my area.
Many hardwood dealers will carry MDF that has a hardwood veneer on one or both sides.
It's heavier that most hardwoods, not weather resistant at all, requires pilot holes to avoid blow outs when using screws, but uniformly flat and makes a great surface for painting.

 

I enjoy using it for jigs and fixtures, for some small cabinets (to be painted), closet organizers, and for prototyping. The stuff is fairly cheap, easy to work with (but can be hard on cutters), and uniform.

When I was making speakers, I used it almost exclusively, because it was a nice and dense material.

The stuff is heavy, about 90 pounds a sheet, so get a friend to help you move it. It also is usually a little bigger than 4 x 8, to allow for dented corners I guess.

The stuff makes a terrible amount of dust, and I try to work it outside whenever possible.

Pilot holes are a must, and I recommend a quick pass with a hand coutersink on the back side of a screw hole to make sure that the screw pulls up tight. Also, the cut end of MDF can soak up glue, so give it a little extra.

The pictures below are all MDF. (The boat is actually skinned with hardboard, not MDF) On the green cabinet, the front edges are trimmed in 3/4 inch pine screen moulding. MDF is a full 3/4 inch, so it fits perfectly. The insides of the boxes and trim were waxed, the outside painted with kid safe paint. It still looks great after 12 years.

 

Actually the reason I became courious about MDF is that I plan to purchase a jewelry box for my daughter in law for her birthday. You will, of course ask, why buy when you are a woodworker. Good question if you are wondering. Well, this is not a small jewelry box, quite large and one that she has taken a shine to. I just don't have the time to make it and for now, my skills aren't up to the task. Anyway, the box is made of MDF and so I am wondering if it will be of very good quality. The price of the box is about $250 to give you idea of what I might expect. It is a stand alone item with several drawers, a mirror and doors. I am thinking that if I like it, in time I can duplicate it in hardwood. Anyway I probably will experiment with the material and see if it works for other projects, thank for taking time to help me on this matter.



Jerry

 

Dust (Fine dust) control is a must as is good respiratory protection. The stuff turns into powder if simply mention the word router anywhere near it.

As mentioned before prime or seal before painting. A good sealer for MDF, specifically, is a 50/50 mix of yellow glue and water.

GCG

 

Jerry, if you plan on experimenting with MDF please be aware that the material makes a lot of bad/small dust while cutting it and you will need to wear a mask while working with it. It is advisable to be in a well ventilated area as well. It will also dull your tools quicker than wood. If you use screws, or even nails for that matter, you should drill pilot holes to prevent the material from blowing out/splitting on you.

 

Jerry, most us look at something commercially available and ask ourselves, " How would I do that?". It isn't often hard to exceed the quality of what we see. The problem is usually how much time and what cost of materials..

 

Jerry, most us look at something commercially available and ask ourselves, " How would I do that?". It isn't often hard to exceed the quality of what we see. The problem is usually how much time and what cost of materials..

Charles-

+1. I have a lot of furniture and cabinet "catalogs." ...and not for the intent to buy from them. For ideas.

 

I tried MDF just once. The dust was a deal killer for me, terrible stuff.

 

Forgive my ignorance but I have been under the impression that MDF is a banned product in the USA.

 

Not banned here. At least not that I can tell personally. Used here in furniture, moudlings, millwork, cabinets... Sold in raw form even in big box stores and building supplys. In DPL Laminate Flooring, the core layer is usually MDF. (Whereas HPL Laminate Flooring the core layer is usually compressed paper fiber.)

Like I said- MDF, very versatile and easy to work with... Just "real world" dust precautions when machining it.

 

Jerry, as you now have learned; Medium Desity Fiberboard is a ferocious producer of dust - a dust that has actually been so thick in my shop (but only one time) that it set-off my smoke detector. MDF sometimes contains a tiny amount of metallic parts - I've even proven this to some of my employees by showing magnets attracted to some pieces. As Doug correctly told you above, it usually is a bit larger than its advertised sheet size - this is because it gets banged-up corners very easily. We use it in my shop for router templates - I am currently making some (grandchild gifts) miniature guitars, violins and banjos (toys only) using 1/2" MDF for the templates and 1/4" MDF for the workpieces on my router table with a bearing-guided bit. I like the fact that it is heavy - because for many things we make (1 of a kind items) it helps to make better displays for our customers. It also is extremely easy to finish with spray paint. It works well for fastener attachments into the faces, but NOT into "end grain" (edges). Pre-drill holes for screws and bolts. If you're going to glue two or more pieces in sandwich-fashion, use some traps before clamping, or the multiple parts will quite likely slide out-of-place, because the glue can act as a lubricant to aid slippage on the super-smooth MDF faces.
If you're into making bird houses for outdoor use, do not use MDF, or you will have some very disappointed feathered friends. When drilling through MDF always drill through the MDF and immediately into a sacrificial board, otherwise there will be bump-outs at the "exit wounds". In my opinion, MDF is a great product for some endeavors; but it is a very poor product choice for a lot of other projects. Full-size (49" x 98") sheets can be a major difficulty in transportation, but fortunately for me and many others it is available in Lowe's and Home Depots in what they call "handy panels" - which are slightly oversized 24 x 48 nominal dimensions. We rarely use full sheets and when we do, it is best to have them vendor delivered for a very small upcharge (as I get older this trick becomes more valid than in past years). Have fun with a dust mask on!

 

I try to avoid anything water based for the primer coat on MDF. Shellac or almost any oil based primer will yield a very smooth finish and can be top coated with most finishes. Love the final result, hate the dust.

 

I think that this thread has caused me give up the idea of using the stuff, maybe a project will come along that will cause me to change my mind. Sooo... this thread has been a success for me, glad I asked. By the way, the issue of time came up and it sure is a issue in our woodworking hobby.

Jerry

 

Hi Jerry

Before you discard the idea of using MDF completely I think I should point out some of it's advantages:-

- Unlike plywood MDF always comes with absolutely flat surfaces which are parallel to each other
- If a profiled edge is required higher density boards such as MR-MDF (moisture resistant), HDF (high density) or deep-route (higher density manufactured specifically for CNC profile routing) will provide a much crisper edge profile
- MDF when laminated with melamine (as MF-MDF) is considerably tougher (better at withstanding impacts) than MFC (melamine-faced chipboard, or melamine as you call it in the USA) leading it's use extensively in shop, restaurant, hotel, bar, office fitting
- MF-MDF suffers from much less edge chipping than MFC which makes it a better material for interior fitout tasks
- MDF is available in a wide variety of nelamine and veneered surface finsihes makiig it ideal for many quick projects
- MDF is relatively inexpensive in comparison to plywood and many other manufactured boards. That makes it a great material for prototyping
- MDF has a flaw-free surface finish and can be painted to a high standard with relatively little preparation
- MDF is available in larger than standard sheet sizes (not sure about the USA, but here 3m x 2m and/or 10 x 5ft are ex-stock from larger merchants)
- Thinner MDF is an excellent templating material as a near perfect edge finsih can be obtained
- MDF is manufactured in a very wide range of (consistent) thicknesses; over here 3mm (1/8in) to 50mm (2in) are available as standard manufactured thicknesses (although 3, 6, 8, 12, 18 and 25mm are most often available)

As with any other man-made board it is essential to ensure that the appropriate material is chosen for the task at hand and that it is stored correctly

Regards

Phil

 

And as stated before since it is nearly dead acoustically it is an ideal material for speaker enclosures. Its flat surfaces make it an excellent substrate for hardwood veneers.

GCG