0

I've been watching videos on building workbenches, and there are a lot of varieties, including one video where they glued a couple of sheets of 1" MDF together for the top.

In this coronavirus era, I'd rather use materials on hand, which happen to include some 2 x 10 fir, and a sheet of 1" MDF. I'm a newbie, so I was thinking that I could start with the 2 x 10s as a base, perhaps rip them so they can go over a friend's jointer and be mostly flat (they are currently cupped, up to 1/8"). Glue them up and get them reasonably flat, then put the MDF on top to make it sturdier and flatter.

I do want bench dogs and an inset face vise.

Any thoughts on what the pros and cons of this approach would be? Or stumbling blocks?

  • One con is it sucks up moisture like a sponge. Wax it well and often ?? . I would incorporate into your design the ability to replace the MDF top with minimal effort. – Alaska Man May 20 at 22:32
  • One of the nicest things about using MDF is that it's so damn heavy. Your bench will be super heavy and super solid. I have one with two 3/4" sheets split between the top and a bottom shelf, and even under crazy abuse, it does not move or walk, etc. – Greg Nickoloff May 30 at 2:16
3

Sounds like it would work fine to me. My first bench was two sheets of 3/4 MDF laminated together and I had no major issues with it. I used it for years and made quite a few projects that I was proud of on it.

There's really only two very minor things that I ran into. When you're drilling the dog holes the center spurs on forstner bits tend to not like MDF. I was able to drill much faster when I had small pilot holes for my forstner bit.

The second issue was that I never felt totally confident with the overhang that the vise was attached to. If I did it again I'd probably back up that area with a batten on the underside to keep it from flexing down.

| improve this answer | |
  • One small con might be that it would be hard to resurface. If it starts to really get beat up, a wood top can be resurfaced whereas with MDF you'll probably be replacing the entire top (though I have no idea how you would do that easily with dog holes. – jdv May 20 at 18:28
  • @jdv I have a large bench in my garage with a double-layer MDF top and dog holes, etc. When I need to resurface, which isn't as often as you'd think, I use to "old" top as a template to cut dog holes in the "new" top. Can also swap the top layer and bottom layer around for some additional mileage. – Greg Nickoloff May 30 at 2:11
3

What are the pros and cons of MDF as a workbench top?

Pros:

  • Relatively cheap.
  • Is already a flat sheet ready to use as a work surface, saving much time and effort.
  • Fairly flat to dead flat right from the start, but, needs good support to stay that way — MDF, like chipboard/particleboard, can sag under its own weight if only supported near the ends.
  • Although the material is sort of friable, it's strong and cohesive enough for use.
  • Uniform texture throughout, so no knots or other hard spots.

Cons:

  • Not as strong or as stiff as solid wood (even pine and other softwoods are stronger in certain ways).
  • Doesn't tend to take screws or nails as well as solid wood.
  • Possibly outgasses low levels of formaldehyde1/sup>.
  • Most MDF doesn't take being wet with water well and can swell badly. But moisture-resistant versions are available — called MR-MDF in some markets — which in addition to the moisture resistance are also generally tougher and stiffer.
  • May not be able to be resurfaced properly. By comparison scraping, sanding and even planing the surface of wooden benches to refresh them is commonplace, as and when needed2.

I'm a newbie, so I was thinking that I could start with the 2 x 10s as a base, perhaps rip them so they can go over a friend's jointer and be mostly flat (they are currently cupped, up to 1/8").

Yes, reduce the wood to smaller, workable pieces as needed to process it into your workbench's understructure.

Since you're a newbie, you'll notice that once cut down the wood will exhibit less cupping3.

Glue them up and get them reasonably flat, then put the MDF on top to make it sturdier and flatter.

There is a major drawback to this plan. MDF is dimensionally stable but solid wood wants to change width in response to differences in temp and humidity through the year. The MDF will essentially stay the same size. While you can accommodate for this sort of thing in certain ways it's generally a bad idea to try to directly attach board materials to solid wood once you go past a certain width, perhaps 18-20" you're into an area where the side-to-side dimensional changes of the solid wood are significant enough that you need to pay attention to them.

What to do instead
However you don't need to ditch your workbench dream using this material entirely, quite the opposite.

Using what you have at hand you can make any number of different workbenches of various styles and configurations. At the most basic a single thickness of MDF can work as a top for now, with the plan being to beef it up later, and possibly add a sacrificial hardboard surface as well. If you have enough material you can laminate it now — a full sheet is 8'x4' and ripping this in half yields 2' pieces, and 24" or slightly less is a very common workbench depth.

There are various ways you can use the fir.

~2 inch material can be used directly and make for a very strong, stable bench. Material of this thickness has been used to make many a woodworking bench that has served its builder well, and outlasted them, as long as the rest of the construction was sound.

A more modern take is to rip the 2x10s into narrower strips (into 2, 3 or 4, depending on how thick you want the final top to end up), then face-glue them together to make a top where the board edges become the top surface4.


1 Formaldehyde-free versions are available.

2 But note that some of this work is used to re-flatten a wooden work surface after it has warped in some way.

3 Warpage of all kinds is reduced when pieces are cut to size, e.g. a noticeable bow on an 8' board may yield two 4' lengths each with only a slight bow. In this case your cupping will be far easier to deal with, and result in less loss of thickness, if you rip the boards into two (note: not necessarily right down the centre).

4 This has numerous advantages, but it's a lot more work.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.