Gappy Joints, For Speed & Strength

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Good chairs stay together forever if the chair maker understands what wood does.

They know it will move, and use this to their advantage.

Bone dry legs going into a slightly wetter seat.
The seat drys over time, the legs take on a tad of moisture and everything stays tight.

A good furniture maker knows that he was born cock-eyed for a reason.

 

Trust out of square.

The key to building swiftly by hand, is to not work like a machinist.

Matching lengths and perfectly square are all essential when you’re using stop blocks and all that.
But this approach by hand always leaves you feeling like you’re chasing your tail.
And it take ages.

Gaps in your joints.
It sounds like an excuse from a shoddy workman.
But there’s a double benefit here.

We’re gonna need a scenario.

Let’s have a classic table and focus a bit on the joinery.

You’ve got four legs and four aprons.
They’re joined together with mortice and tenons.

When we prep these parts by hand, aiming perfectly square is a time consumer.
And getting nice tight shoulders all the way around on every joint is also a time consumer.

That’s what a machinist would need to do.
But we don’t have to.

Aim for just under 90 degrees between the joinery faces and the outside reference faces. And then the same between the two outside faces. This makes prepping swift, whilst ensuring perfect show faces to your joints.

Instead, deliberately plane your legs wrong.

Don’t aim at 90 degrees, but go a bit less.

Don’t be precise about how much less.
That’s the whole point.
Just get them as close as you can to 90 without worrying too much, because aiming for out of square is wonderfully tolerant.
Just be sure to check from your reference faces each time (they should be the two outside faces).

So that’s made that part a doddle.

Now for the tenons.

We’re aiming at gappy joints.
Scribe your shoulder all the way around.

On the show face cut to the waste side of the line as you would normally.
But on the back of the apron cut to the other side. The ‘good’ side.

When the joint goes together the face will be tight, but the back will have a small gap.

Fettling the face of the joint is now dead easy.
We can get it perfect without having to mess about going around the other side and all that.

Sawing the tenon shoulder – be sure to keep to the waste side of the line on your show face, but removing the line, even going in to the good stuff can be beneficial on the inside face.

Working in this manner gives us two benefits.
The first benefit is clearly tremendous speed.

But there’s a second.

When we peg the whole thing together, all the joints will pull less than 90 degrees.
Basically each joint will want to twist.

This is because the tenon will be able to slip in just a tad more on the back of the joint due to that gap.
And because the faces of the legs are inward of 90 degrees.

A perfect show face, but a deliberate gap can be seen at the back of the joint.

Once the whole lot’s together, the joints will work against, and sort of counter act each other, so that the table will still sit square.

But that twist creates tension.
The benefit here is a table that will be far, far more rack resistant, particularly over time when the timber does all of it’s moving.
It’ll also be a lot more rigid over all.

So the right side of wrong gives us a load of speed, and makes a stronger table.

 

Aiming at perfection is intimidating.
Particularly when you’re starting out.
In our Hall Table Video build, all of the time-saving approaches have been exaggerated to help you get a good grasp.
We’re a long way in to the build now – this week we got our base assembled, next week we move on to the top. You can find details of the build here.

22 Responses

  1. Greg Harper

    Excellent post, Richard. I’m new to this field of study, and waste loads of time working towards perfection. Tips like this are immensely helpful to a beginner like me – keep the excellent work coming!

    Thanks!

    Reply
  2. Marcus Nielson

    I love your contrast of a machinist and a handtool woodworker. As a beginner I find myself naturally wanting to think like a machinist not a woodworker. Very enlightening!

    Reply
    • Jeff

      Couldn’t agree more! It’s hard NOT to think like this, especially when you see perfection benches in videos.

      Reply
  3. John

    Thanks Richard – I am enjoying the build video. Do you have another example of ‘the right side of wrong’ that would apply to functional dovetails (vs posh ones)?

    Reply
  4. David Gendron

    Interesting approche mate… Good reasoning… So should I throw all my square out 😉

    Cheers

    Reply
  5. Kermit

    It’s very important for handtool woodworkers to remember Richard’s appending of “-ish” to words, such as “squarish.” So many of us learned to make things “dead nuts” square, flat, and coplanar. Learning when “-ish” wins over “dead nuts” is a toigh lesson.

    Reply
  6. Salko Safic

    I understand your reasoning behind it all, but even when I do make a mistake and a gap I shown it bothers me every time I look at it. How in the world would I be able to take your approach and teach myself to be sloppy just to speed up production. They say time is money yet I still work for peanuts.

    Reply
    • mark jenkins

      you are missing the point, the gaps are where they are not seen. What you do see looks perfect.

      Reply
      • Michael Ballinger

        It’s not sloppy when it’s intentional. It’s not just about speed but strength. Tension is used heavily in traditional timber framing, think of draw boring as well, you’re offsetting the hole to put tension into the joint and make it tight. It’s a mind shift, the gap on the back might be a little exaggerated to prove a point, but you could probably make the difference very slight and it would still work.

        Reply
  7. Mohyudin

    Thanks for these tips. I always appreciate your insights. Especially on playing to the strengths of hand tools and not falling into the trap of creating unnessary work by trying for percieved perfection where it doesn’t count. Plus I needed an excuse for gappy joints (I may have got the gaps on the show face though!). Any plans for face to face classes? Keep up the good work

    Reply
  8. Ken Haygarth

    Richard makes perfect sense as usual, but I just can’t bring my self to do it. 😉

    Reply
    • Ivan Walker

      Hey Bro!
      Just give it a try, nothing to lose and . . . . you just might find yourself . . . . “Doing it”.
      Good luck Ken.
      Ivan.

      Reply
  9. Mitchell

    Modern consumers’ aesthetics and notions of high quality have been molded and fostered by the standards of industrial processes. Making the bottom of the tabletop as smooth as the top surface isn’t an advantage of industrialized manufacturing; it’s a necessity to keep the production procedure moving smoothly. As woodworkers, we must recognize how influenced our tastes and standards of quality have been unduly influenced by mass marketers who want to sell us products.

    Reply
    • Ivan Walker

      Almost utterly agree with you Bro, almost!
      ‘Utterly’ “Influenced”. Now me ‘n’ ye are on the same space . . . . Gaps ‘n’ all.
      I utterly enjoyed your post/rant.
      Good luck Mitchell.
      Ivan.

      Reply
  10. Larry Watson Woodworking Studio

    Chairmaker forced to turn furniture restorer is like a surgeon forced to turn first-aider.

    Reply
  11. Ivan Walker

    Hello Richard!
    I tried your “square-ish-ish” method last night and my joints ended up being . . . .
    . . . .”Dead nuts”,
    . . . .”Co-planar”, “You’d think they’d just come out of a production machine”
    . . . .”perfect”!!
    I can’t do right for doing wrong . . . . (in all my life).
    You, kind Sir, gave me the smallest of encouragement to do something wrong-ish on purpose-ish and what do I end up doing? I get it ‘on the money’. Right! .. No! .. Wait! .. Wrong! .. No! .. Wait! ..
    Ah FFS I give up, I’m away to IKEA!
    Keep ‘er lit Bro!

    Reply
  12. Arthur Mauseth

    Richard,

    After reading this article, it made me think of my neighbor. He has a foundation problem he had a bid on at the high end of $25,000. Knowing I lay brick, he asked if I could teach him enough to do the job on his own. Sure, “I said.” Explained to him I had everything needed to do the job, but he would need to get a trowel. I’ve never been good at sharing tools. A week later, he is sitting on my porch with an implement barely big enough to butter my toast and a bricky contraption he purchased to lay down a perfect 3/8″ bed joint. Withholding a burst of snickering in my attempt to explain to him the device for all practical purposes, might be useless in this situation.

    Attempting to emphasize several critical issues in pursuit of a pretty perfect bed joint won’t matter much if your last course comes up short beneath the sill plate, backer rod, and caulk can’t hold the weight of a house. If you end up high, trying to pound courses down is impossible to do in limited space. He continued to insist his research with the help of YouTube has him on the right track.

    I opted to set him up in his garage with a mockup to lay brick with practice mortar to develop his skills.

    Two years later, his foundation has deteriorated even more, and I can only guess the late night light beaming through his garage window is because he’s still in pursuit of perfection, or getting ready to write a check.

    Perfection may be the elusive foe, trust your eye and learn to adjust when needed.

    Arthur

    Reply
  13. Richard

    Wow!

    What is this? The woodworking edition of The Emperor’s New Clothes?!

    As an old school teacher, I would say this is best way to train the new crop of traditional woodworkers, because this approach will ensure that no one will fail their training. “Not good enough” under the current standards is the new “Good Enough.”

    The best learning point of all comments here is…

    When it is intentional, it is (fill in the blank, as you see fit).

    Reply
  14. Mark Dennehy

    Gave it a try : http://www.stochasticgeometry.ie/2018/01/20/offset-shoulders/

    Probably a small chest isn’t the best place for it but maybe some sort of face frame between the chest and its lid could act like edge banding does on plywood and hide the gappy bits from view. I was seriously happy with how fast I could get the joints together though, no more chasing my tail fettling both shoulders of the joint.

    Something to note though, is that if you’re as cack-handed as I am, you’ll wind up with too large an offset. Cutting the shoulder so you have a kerf or less of an offset needs a tad more skill than you’d expect!

    Reply

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