Shopsmith Forums

this is a little new to me, usually I use ply for a lot of my work type tables and jigs.

But seeing how my birch 3/4 ply isn't laying as flat as I would like, I was thinking of the mdf wood that I see many of you use.

Couple of questions.
This is very similar to "particle board", but no big "chips" in it. right?

if you use it for a top, do you laminate over it?

and what about making a slot like for a miter gauge or featherboard, does the slot hold up or will it crumble?

TIA

Discard any ideas of using particle board for your router table; it is too unstable for this application.

I good quality MDF (I would use no less than 1" thick) will work fine. It has a natural smooth surface and mills easily though it creates a lot of dust. Use a mask!!

If you chose to go this way, plan on sealing all exposed surfaces. MDF will absorb moisture and will swell enough to upset orientation. Do not over look the inside of areas like miter tracks.

I would suggest that you resist the box stores when you are buying MDF for this sort of project. You will have to purchase a full sheet at a wholesale distributor but I think you will be happier in the long run.

A local source:

Hood Distributors
501 South Toole Avenue
Tucson, AZ 85701
520-792-9966

Personally I despise particle board. I think it is all of the cheap Ikea furniture I owned in my 20's. I don't think MDF & particle board are in the same ballpark.

MDF is a great less expensive alternative to plywood. It remains very straight and cuts & routes very nicely. I picked up 30 sheets of 3/4" MDF 2 months ago & have built a bunk bed for my kids and am about to build on of those "Ultimate Tool Stands".

The MDF I got was already laminated like melamine but I am sure that you could very easily laminate it with a nice hardwood. I am sure other have tried this. I just haven't had a need to do that yet. The stuff glues well.

The only downside is it can be extremely heavy & is prone to cracking/splitting if you drill or screw to close to the edge. I had to load the entire 30 sheets into my Sienna mini van so let me tell you that stuff is HEAVY!

Hope that helps some.

MDF (medium density fiberboard) is a world away from the old K3 or particle board. Most importantly it is dimensionally quite stable wet as opposed to the old stuff that would instantly blow up like a puffer fish at the mere mention of water. It actually not only has no "big chips" but is all an exactly uniform dust.

You can laminate over it. Many high end custom furniture makers use it as a stable base for veneering over. I have used it this way with great results as there is no grain to telegraph through.

To harden anything like this or softwood to make it more durable I would apply a couple of coats of S1 epoxy sealer. (sold here under the "Industrial Formulators" name. They are a Canadian company that was bought out by System Three so it may be found in the US under either name, I don't know.. never looked for it there.)

Finally I love my birch ply for benches and worktables but it's not always flat enough for all jobs. I have a low 4' x 8' assembly table that needed to be dead flat to use for cabinet ass'bly etc. so I made it as a tortion box. Thats one way to flatten it perfectly.

Paul M

Yup, it is heavy. Somewhere around 70-90 lbs per sheet.

dusty wrote:Yup, it is heavy. Somewhere around 70-90 lbs per sheet.

Back in the 80's they made a HDF aka heavy density fiberboard. It weighed about 3 pounds more than a full grown cow!:D

mbcabinetmaker wrote:Back in the 80's they made a HDF aka heavy density fiberboard. It weighed about 3 pounds more than a full grown cow!:D

I may have encountered some of that. I short time ago I was given the opportunity to salvage some materials out of an architect's work shop.

I knew that the counter tops would be heavy but I was really surprised at how heavy. They seem to be at least twice what I was prepared for.

LowDensityFiberboard IS "particle board".
MediumDensityFiberboard is the next grade up.
HighDensityFiberboard is the top of the line (if you consider sawdust quality), and is still available. For more detail concerning the differences between the "grades" of compressed sawdust board, see this postfrom over a year ago.

MDF is very stable and many may not know but there is MDF that is totally waterproof and is often used for signs. I thought it was called MDO but doing a google search I find MDO stands for MDF overlaid on plywood ????

There is also a rare but avail product called HDF high density fibre board that is has more resin and compressed under more pressure. I'm told it is nearly waterproof also.

I love MDF I just hate the weight and the dust. The weight can be dealt with if you have the board cut where you buy it or use a guided saw system. But if you bring a full sheet home you have your hands full if you try to cut it on your SS.

I love the look of MDF with a rich oil finish. To me it looks like leather.
I have found that MDF soaked in Tung oil is as near water proof as I need. I used MDF for my Radial Arm Table top. I coated many times with Tung oil and I can't tell you how many times by mistake I have set something wet or a sweating glass of ice tea on the RAS and so far no problem not even a mark.

I sold!

Ed in Tampa wrote:MDF is very stable and many may not know but there is MDF that is totally waterproof and is often used for signs. I thought it was called MDO but doing a google search I find MDO stands for MDF overlaid on plywood ????

There is also a rare but avail product called HDF high density fibre board that is has more resin and compressed under more pressure. I'm told it is nearly waterproof also.

I love MDF I just hate the weight and the dust. The weight can be dealt with if you have the board cut where you buy it or use a guided saw system. But if you bring a full sheet home you have your hands full if you try to cut it on your SS.

I love the look of MDF with a rich oil finish. To me it looks like leather.
I have found that MDF soaked in Tung oil is as near water proof as I need. I used MDF for my Radial Arm Table top. I coated many times with Tung oil and I can't tell you how many times by mistake I have set something wet or a sweating glass of ice tea on the RAS and so far no problem not even a mark.

I sold!

I starting to come around also!:eek: Started collecting culls from HD as potential source material.

Yes this stingy old curmudgen checks it out every trip!