On Slab Workbenches and Meaningless Data


Reader: “How flat does my workbench need to be?”

Me: “Flat enough to work.”

Reader: “But how will I know when it’s not working?”

Me: “You will know.”

And really, that is all there is to say about the topic that is meaningful. But as this is a blog, I am going to add some more words so you feel you are getting your money’s worth.

Workbenches don’t have to be all that flat to function well. Even if you have significant low spots that you can detect with your hand or eye, the bench can still be perfectly functional. Why? Several reasons.

We don’t use all of the benchtop surface for high-tolerance work. Consider the areas where you handplane things. That’s your “special place.” It needs to be flatter than the areas you don’t use. Example: I don’t have a tail vise on my oak workbench, so I don’t care about the extreme right end of the benchtop.

Second: The wood we work is stiff. So even if your special place is wonky, a typical 3/4”-thick board will behave just fine there. (Plane an 1/8”-thick board there and you will have a different experience; but I don’t plane 1/8”-thick boards on a benchtop.)

Last week, my oak workbench stopped functioning. My special place was in disarray. What had happened was this: The top had shrunk, and so the end grain of the front left leg was interfering with the planing stop. I knocked down the end grain of the leg with a jointer plane in less than five minutes, and my special place was ready for work. But because I am mostly Teutonic, I was compelled to dress the rest of the top.

It took four passes with a jointer plane to true the top back to a state that is overkill.

I also had a small gap appear up near the planing stop. This has happened on many slab benches I’ve built before. I pushed some epoxy into the gap, a procedure I have covered many times over at my blog at Popular Woodworking.

Total elapsed time: About 45 minutes.

But that’s not the end of the story. During the summer I brought my daughter’s slab workbench back into my shop to use it for photography for “Campaign Furniture.” I haven’t flattened its benchtop for three years. It has been working fine, but I became curious and picked up a jack plane…

And now this blog entry is too long. I’ll finish it later. I have a date with a creepy janitor.

— Christopher Schwarz


About Lost Art Press

Publisher of woodworking books and videos specializing in hand tool techniques.
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15 Responses to On Slab Workbenches and Meaningless Data

  1. John Hippe says:

    Lesson learned…I can detect with my hand and eye if my special place is a bit wonky…

    • silvibill says:

      it depends very much on the type of work you are doing. For real cabinet making, e.g. smoothing panels or frame and panel cases or for organ windchests done the traditional way or for truing ans smoothing keysheets for keyboards the entire depth and a much of the length as the work is wide MUST be flat and true. With a Roubo type bench such I made for myself (3mtrs long) and only planing dog at the far end, this will not necessarily be the entire surface, but I do my best to keep it true anyway. And free of glue and other crud. That is relatively easy since I use only hot hide glue.

  2. Gene ORourke says:

    Always free and worth every penny……

  3. Has that plane been to Catharine Kennedy for some improvements?

  4. shopsweeper says:

    I’ve been working with a local Blacksmith Association this year, learning. And I noticed that every blacksmith has a “sweet spot” on the anvil surface were things are better. Better flatness, better rebound, better centering over the mass of the anvil+stand. It made me think of the small corner of my bench that I actually do all the work on.

  5. A little off topic…
    Why are planing stops so long? That sucker must have 12 inches of stroke. Wouldn’t anything that high be impossible to plane (short of standing on a stool, that is).

    • lostartpress says:

      Part of it is that the top can be 6″ thick. So 6″ is inside the benchtop. Also, I use the stops 6″ up off the benchtop for edge-planing. Works brilliantly.

  6. rondennis303 says:

    Chris –

    Beautiful summary. Great insight. When do we get to the roles of the straight edge & winding sticks?

  7. Ben Kamp says:

    Now really when are you going to install the drawer and grease box on that bench?

  8. What do you plane 1/8th boards on? I’m curious why the bench is not suitable.

  9. Matt Wilson says:

    As a career science researcher, I can say there is no meaningless data…only meaningless interpretation

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