Last week, in a moment of fevered DIY insanity, I decided to spend an entire afternoon tricking out our wonky breakfast nook table with mortise and tenon joinery. I found the base of this table in one of Los Angeles’ lesser alleys many years ago and, back when I had higher levels of tolerance for lower levels of craftsmanship, I haphazardly fixed the table with screws and nails.
Making the mortises and tenons took forever even though I was working with power tools–a plunge router to make the mortises and a table saw to cut the tenons. Of course, a great deal of the time in the workshop was spent in idle chatter. My workshop is right on the public sidewalk and serves as a kind of conversational trap for every passing neighbor and dog walker. Kelly suspects that the exchange of neighborhood gossip is the real purpose of the “workshop.” I will neither confirm nor deny this.
But back to the table. Mistakes were made. While routing out one of the mortises I hit a hidden screw resulting in a shower of sparks and a ruined bit. And then there’s those more pressing chores I was ignoring such as fixing broken irrigation lines, finding a decent house painter, rehabbing our forlorn garden etc. Rome is burning and I’m taking the wobble out of a ugly breakfast nook table.
But there’s a real sense of satisfaction when you glue mortises and tenons together. Suddenly, what was just a pile of potential firewood comes together with a solidity that nails and screws simply can’t deliver. You could now park a Hummer on this table which, given we live in Los Angeles, could actually happen.
While the half lap is stronger, Fine Woodworking’s tests vindicated the traditional mortise and tenon over pocket screw joinery (similar to what is used in Ikea furniture). Pocket screws failed under 698 pounds of pressure while a 3/8 inch mortise and tenon was able to sustain up to 1,444 pounds before failing.
Next up, ignoring all those important chores in order to make a fancy new top for the table with some ridiculously time consuming butterfly inlays. I’ll post some pictures of the completed table once the top is done which should be around ten years from now.
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Rome is burning at my house, too, and in some of the same places that you mentioned:(
Wow with your energy and determination you could build a brand new table using all that you have recently learned! I have read rootsimple for years. I just thought it was about time to let you know I really enjoy your blog! Thank you for sharing. I was there when Kelly had her heart fright. Every time I visit I remember and I am so happy everything turned out ok! But I do miss Kelly’s unique voice in the blog. But I understand. It is best to reduce stress.
I have! Please thank your dad for some very, very helpful how-to writing.
I wonder if you’ve read my father’s blogs for Fine Woodworking; his name is Tim Killen. He often writes about furniture design using SketchUp.
Regardless, fun to read this post. I appreciate your love of good craftsmanship.
I love the half lap. I used it so much in my chicken coop.
Question from a noob: what glue do you apply? I just cant imagine how a glued half lap could be stronger than screws..
Glue is stronger than screws, believe it or not. And I use Titebond II.
Half-Lap vs Mortise & Tenon strength;
When Fine Woodworking states that a half lap is the strongest joint, I have to remember that the statement is from “Fine Woodworking” where every joint is perfectly made of first quality wood.
In the DIY world where the workshop is filled with varying quality and quantity of tools, even an advanced woodworker will probably not have perfect joints. Here, a Mortise and Tenon reigns supreme. Minor errors can be compensated for without throwing out the work and starting over. Slight alignment errors can be compensated for by shaving and shimming the tenon. You don’t have to tightly clamp the pieces together, you just need a bit of pressure to hold the parts in correct alignment. Naturally, we all want to do the best work possible, but it’s nice to know that when things don’t go exactly as planned, a Mortise and Tenon is actually a very forgiving joint, but still very strong.