Learning and laughing, I had a great time at WIA. Here are a few snapshots with preceding captions. A few closing thoughts follow the photos.

I spent much of the weekend hanging out with Mark Harrell of Bad Axe Tool Works, here demonstrating one of his superb backsaws. Looking on are Vic Tesolin of Lee Valley and Al Flink, a student of Mark’s who became my saw filing teacher for an afternoon. In the world of saws, BATW is playing chess while most are playing checkers.

The same goes for shooting boards and Vogt Tool Works. Tico has added to his line of inclined shooting boards with models designed specifically for new shooting planes available from Lee Valley and Lie-Nielsen. If you don’t already own a Vogt shooting board, you owe it to yourself to check out Tico’s products.

When Matt Vanderlist talks, woodworkers listen.

Speaking of great communicators, I asked Marc Spagnuolo to look as cool as possible for this photo. Yes, I know, that’s like asking Kareem Abdul Jabbar to look tall. The Wood Whisperer met my request with his ready sense of humor.

Popular Woodworking magazine Editor Megan Fitzpatrick and I, your devoted scribe, made a deal, or so I thought, to look as sappy as possible for this shot. Megan, no doubt quickly bringing to mind some Shakespearean plot, opted to appear quite levelheaded, while I succeeded rather spectacularly with the original plan – don’t you think?

I will not reveal what Chris Schwarz did moments before this shot, but only say that he switched the anatomical focus of his jocularity from his customary posterior to anterior just in time for the photo. (No, he’s not adjusting the square on his shirt.) Can you tell that Deneb Puchalski and Tom Lie-Nielsen are covering for Chris with forced laughter?

Seriously, it is hard to appreciate the beauty of the Lost Art Press books until you handle them in person. The same is so for the grace and functionality of Lie-Nielsen tools.

Recognize the guy in the middle?

Ron Hock of Hock Tools has done so much for woodworkers for many years.

Woodworkers are similarly grateful for the contributions of Joel Moskowitz of Tools for Working Wood and Gramercy Tools, here chatting with Fred West.

It was wonderful to be around so many people who love what they do, in this case, woodworking. The joy was palpable and contagious, while the learning flowed naturally. The direct link between action and result inherent in the craft of woodworking punishes pretension, so the down-to-earth nature endemic among woodworkers comes as no surprise.

I am grateful for the many conversations I was able to have with sincere, masterful makers. Some that I especially savored, such as with Mark Harrell of Bad Axe Tool Works, and Robin Lee of Lee Valley Tools, were alone worth the airfare. Thank you also to the many people whom I met who kindly mentioned their appreciation of my writings.

Special thanks to the Popular Woodworking crew for putting on a wonderful event!

This will start a few posts here on sawing tenons by hand, but first let’s first ponder the mortise and tenon joint in general. A joint that has been used successfully for thousands of years certainly deserves some thought.

What accounts for the joint’s legendary strength? Imagine trying to snap an “L”-shaped M&T construction. The mechanical lock of the tenon shoulders meeting the wood surface around the mouth of the mortise effectively transfers the imposed stress to the glued surfaces of the tenon cheeks against the mortise walls.

The stress on the glued surfaces, in turn, is a shear stress – and we know how wonderfully glued wood surfaces resist shear stress. Voila: a strong joint!

In fact, rarely will a reasonably made M&T joint itself fail. Rather, it is the wood around the joint that is more likely to give way.

Looking at the mortise and tenon strength tests detailed in Fine Woodworking magazine issue#203 (February 2009), we can see that it is almost always the wood around the mortise that failed, even when the tenon itself was too weak to hold up. In the real world, I cannot recall seeing any decently made tenon break, but I have seen the wood around the mortise fail.

I also observe that the only real danger to a tenon pulling out in a properly made joint is from the all-powerful forces of hygroscopic wood movement conflict. This may produce some gapping at the shoulder line, especially in injudiciously designed joints.

In most woodworking instruction, much attention is paid to proportioning the thickness of the tenon with respect to the thickness of the rail. Recommendations are typically that the tenon should be 1/3 – 1/2 as thick as the rail itself.

Yet, knowing from where the M&T derives its strength and how it is capable of failing, it behooves us to look at the proportions of the joint as a whole:

• Especially consider the robustness of the wood surrounding the mortise.
• Consider the area of shear-stress glue surface – the tenon cheeks.
• Consider the nature of the dimensional conflict within the joint. The corollary here is that glues with a bit of give, like PVAs, have an advantage.

One more possible consideration is the lever arm force exerted on the stile (mortise member) by the tenon. In the FW article, look at how the humble stub-tenon and biscuit joints failed: the stile split along the grain near the end of the tenon depth. That’s a lot harder to do with a deeper tenon where the leverage works out to be not as lopsided, and the tenon engages more peri-mortise wood, not to mention the direct value of the greater glue surface area.

I hope, readers, you are not now expecting me to delineate a set of rules for proportioning a good M&T joint. Sorry, there are simply too many construction situations and circumstances. However, thinking clearly about what is going on in the joint and the considerations listed above should bring you to good joint designs. Furthermore, frankly, there is a good amount of slack here – even non-ideal but more-or-less reasonably designed M&Ts will hold up.

But don’t make a sturdy 3/8″ thick tenon to sit in a mortise with a 1/8″ outside wall!

Coming up: sawing tenons by hand, starting with sensible joint layout.