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My First Mistake

My first mistake was thinking that I was smart.

Now I don’t suggest that I should have adopted the method that my father used on me. When I was a young lad and did something dumb, he would yell at me that I would lose my head if wasn’t attached. He was a confidence builder that man.

I simply thought that on this fateful day that I had it all figured out. That I could hear any train coming at me and I was ready.

I had borrowed two scaffolds from my sheet rocker, Garrett. Now Garrett was a generous guy. He was also what I would call a big drink of water, 6′ 4″ or 6′ 5″. Yet he was not imposing. He just took up a lot of the available air with his ready smile and attitude. Oh sure, he could squash me like a cherry tomato but I thought he was a good guy who had standards for his work and that meant something to me. And for a sheet rocker he was positively a thoughtful man. We would have these conversations about the old days because of what song was playing on the radio which reminded him of when he used to raise hell up in the San Juans. He had given up that drinking life.

One day Garrett talked to me about his wife who was the brains of his outfit now. Turns out she had been a code cracker in the Navy. Since he was Navy too, once upon a time down in San Diego, and since he needed to clean up his act, she was the perfect woman for him. They married and had been up in the Northwest countryside for 20 some odd years together.

Damn thing was, she was a few years older than him and starting to show signs of forgetfulness. Garrett started telling me about how she had scared him one night talking strange and nonsensical stuff and it made him worried and nervous. Like he could hear the freight train coming but there wasn’t anything he could do to stop it. Now there is nothing that can take a man’s knees out faster than watching someone that he loves get done in by illness with not a cure or a prayer in sight to help. And listening to that train in the distance is no useful activity for a man. Better to keep your head down or up in his case in your work and just stay busy.

Conversations like this between guys are shared and forgotten mostly. They don’t mean a damn thing the next day to a guy and they mean everything in the moment. Guys don’t share their feelings unless they feel comfortable and trust another guy. Usually the most trust you get out of another guy is the understanding that the next time you see this fella he’s going to insult you the best way he knows how.

He might, for instance, comment on how poorly you have always played poker or backed the wrong Philadelphia football team. Or he might walk up to you and say: Gee you walking funny these days? Or did your bladder diapers ride up on you just now? That kind of insult means he cares.

Anyways, I held this information about his wife’s diminishing capacity with honor and hope that it was just an isolated event. That train is still off there in the distance for us all, but maybe he would have some more good years with her. I hoped with my heart for that. Best I could do for a prayer right then as I am reformed catholic. Excuse the hell out of me.

Now to get back to the point of this story I want to remind you that even when you think you’re smart and you think have it all figured out, you may have to re-calibrate this stance of yours in light of the evidence that will be presented to you. This evidence may indicate that you may have just done something remarkably stupid. So back to my scaffolding story and you’ll see what I mean.

I knew I could load these two scaffolds up all by myself. But they didn’t both quite fit into the back of the bed of my pick-up truck standing up. Plus it was a curvy road to drive and they were a bit top-heavy. I disassembled the parts and laid them all out on the ground. Now all I had to do was load them up and haul them off. Easy enough. These were not imposing objects once taken apart.

I got one big panel in and then another sliding them in over the tailgate. Both stuck out over the back of it. That was fine. The smaller scaffold almost fit in lengthwise but not quite.right in that in-between kind of spot.

It was just a little cock-eyed so I gave it a final shove and it still wouldn’t go down into the bed. So I walked around the side of the truck and I had my right hand behind this panel near the front of the truck bed and my left was pulling it closer to straight as the panel rested on the back of the tailgate. All of a sudden it found its entry point and the whole panel slipped down a few inches pinning the finger next to my right pinky tight to the truck bed wall.

It hurt. That’s the first thing I noticed. The panel had slipped down just a bit but it had me locked down like a 73″ long steel wedge and I could not move my hand. It hurt. That’s the second thing I noticed. My finger was lodged in place right near where the digit met the palm of my hand and when I pulled at it, I thought I might tear or break it off. And the panel would not move and I could not lift it because it was wedged in by its fall and I could not crawl into the truck bed without moving or ripping off my finger and holy hell, I realized that I was alone and pinned against my truck and might suffer some serious finger damage because I had thought I was smart and doing everything right when something slipped on me. I never saw this train coming.

My finger took up most of my concentration now. It hurt. This was what I noticed. This situation was a reminder no doubt sent by the scaffolding gods that I had made a tactical error. I had put my hand in the wrong spot and I had gotten it pinned. How did this even happen?

Didn’t matter. Now what could I do? I mean there was no one to call. My phone rarely worked out where I was plus I would have a hell of a time reaching it with my left arm trying to reach into my right hand vest pocket and oh yeah my right finger was really starting to pain me.

Remember that movie scene in Sometimes a Great Notion where the brother has his leg trapped by the log that rolled onto him and the tidewater is rising around them and the brothers realize that there is nothing to be done because that log won’t move? I did not want to think about that scene in the movie Sometimes a Great Notion.

I tried to focus instead on my options because the pain in my finger kept reminding me about the importance of my immediate situation. I tugged at my finger again. No luck. I pulled it, I pushed it. No luck. I tried going up with it and then down with it. I tried moving the panel again. No luck. That panel was stuck in there and too heavy to lift up with my left arm alone from where I was at the front of the bed. I had no leverage on it. My leg couldn’t kick it because I couldn’t get it over the truck side wall. The dang panel wasn’t heavy. I was just stuck with it and with my hand in the wrong spot.

I think it’s maybe the glue-ups I’ve done that saved my finger. All those times when the clock was ticking, like it certainly was ticking on me now, and I had to come up with a solution or lose my piece in the simple assembly of it. No time for recriminations. No time for blame. No time for self-pity.

The only thing I could figure out to try was to make myself smaller and see if that worked. I mean my finger was also part of this whole wedge package so if I could make it smaller somehow, don’t ask me how, maybe it would move. I was willing to try anything even trying to go Zen on myself in the middle of a pick-up bed crisis. I pulled on the panel back a little with my left hand and then I told myself to relax my right hand and that finger. Relax. That’s what I said to myself: Relax, so the muscle or pad or whatever the hell it is that’s inside your finger there wasn’t so large and bulging out so much so it would shrink enough so I could move the panel just a smidgen and remove my finger.

And by golly it worked. The panel slid to the side just a bit and out popped my very red and pained finger and I went to put some ice on it. Then I thought about how such a simple job like this could have turned into such a disaster for me. Man, here I thought I was being smart, taking everything apart, and look how it turned out. How does this happen, I asked myself out loud. Now the self-pity part kicked in. Don’t you attach your head in the morning? Recrimination time. And et cetera.

Until I thought about the fact that I had just saved my finger and learned another valuable lesson. Just cuz I’ve dodged a bullet every now and then does not mean that life or the great wedge or simple physics might not bite again if I’m not thinking.

Accidents are a silent freight train but they still can hit you hard. Circumstances can change on us in a hurry. Good spots can become bad ones and seemingly right decisions can turn into very bad ones. You cannot complain about this series of events. There is no time to moan about how hard you got it. You have to figure a way out before you lose something precious. Don’t presume that you’re smart. You are probably not entirely right. You are certainly not entirely wrong. But think before you act. My daddy was certainly right about this one thing: use your head.

 

Wedged Mortise and Tenon

Wedged Mortise and Tenon

This joint will never loosen!

By Tom Caspar

 

Tap, tap, tap. The wedges go home, the glue squeezes out and a big smile lights up your face. “This joint isn’t coming apart for a hundred years,” you say. “It’s as solid as a rock!”

Making a wedged mortise-andtenon joint is richly rewarding. Once you understand how it works (see "How the Joint Works," right), you can’t help but admire the joint’s elegant simplicity. It also sends a message. A wedged joint says to one and all, “This was made by a skilled woodworker.”

Where could you use a wedged joint? It’s a candidate for any joint that receives a lot of stress. A table base such as the one shown here, is a good example. Pushing or leaning on the table might slowly force a standard joint apart, but wedges keep this joint locked together.

The wedged mortise-and-tenon joint isn’t difficult to make, but you should have some experience making standard mortise-and-tenon joints before tackling it.

 

Tools required

To make this joint, you’ll need a tablesaw, drill press, plunge router, chisel and a bandsaw. If your mortise’s width is 5/8" or more, like the mortise I made, you’ll need a 1/2" dia. top-bearing flush-trim bit. If the mortise is more than 3/4" deep, you’ll need a bottom-bearing flush-trim bit (see Source, below). For a mortise less than 5/8" wide, you’ll need a straight router bit and a fence or jig for your plunge router.

 

Rout the mortise

Before you begin your project, make a prototype joint (see “Designing Your Wedged Joint,” right).

It’s good practice to start with the mortise for any type of mortise-and-tenon joint. It’s easier to fine-tune a tenon to fit a mortise than the other way around.

This is a through-mortise, meaning it goes all the way through the workpiece. My favorite way to make a fairly large one is to remove most of the waste on the drill press and then use a plunge router and template (Photo 1). This method works particularly well in thick stock, because it makes a mortise with absolutely straight walls. That’s important for appearance’s sake in a through joint, because you can clearly see from the outside how well the mortise and tenon fit together.

Make the template from plywood or solid wood by gluing four pieces together. The inner two pieces are the exact width of the mortise, but their overall length is unimportant. The outer pieces must be long enough to allow room for clamps. Space the inner pieces apart by the length of the mortise.

Before you start routing, use the template to draw the mortise on the workpiece. Drill out most of the waste using a Forstner bit that’s 1/16" to 1/8" smaller than the mortise’s width. Make overlapping holes to remove as much wood as possible. Rout the mortise (Photo 2).

 

Taper the mortise

Tapering the ends of the mortise requires a razor-sharp chisel; there’s no practical way to do it with a router. You must use a chisel to square the ends of a routed mortise anyway; so tapering isn’t that much extra work.

Make a 1-1/2" to 2" thick block to guide your chisel. Cut one end square. Cut the other end at the angle you’ve chosen for tapering the mortise and wedges. I’ve found that a 3-degree angle works well.

Use the guide block’s right-angle end to square the back of the mortise. Chop about one-fourth of the mortise’s depth. Turn the workpiece over and position the block a short distance away from the end of the mortise (Photo 3). The exact distance depends on the mortise’s depth. You’ll want the taper to extend approximately three-fourths of the way down the mortise. On a 3-degree taper, shifting the block 1/16" from the mortise’s ends results in a taper about 1" deep.

 

Make the tenon

Make the tenon any way you want. I use a tablesaw tenoning jig to cut its cheeks, a bandsaw equipped with a fence to rip its top and bottom sides and a tablesaw’s miter gauge to cut all four shoulders. The tenon’s length is up to you; it can be flush or stand proud of the joint.

Fit the tenon to the back, untapered side of the mortise. It should be no more than a paper thickness smaller than the opening. If your tenon stands proud, chamfer its end using a block plane or file.

The next two steps are unique to this joint: making the strain-relief holes and sawing kerfs for the wedges. Start by marking and drilling the holes (Photo 4). Their location and diameter determine the flexible strips’ thickness. In most woods, such as the white oak I’m using here, I drill 1/4" dia. holes centered 1/4" from the edge. This makes the bending strip a flexible 1/8" thick. Holes that are only 1/8" are commonly used for this joint, too, for types of wood that bend easily, such as maple and ash.

For the saw kerfs, draw lines that connect the holes to the tenon’s end. Traditionally, the kerfs go to a hole’s center, but I aim for the hole’s inside edge (Photo 5). Looking headon at the completed joint, I believe this divides the tenon into more pleasing proportions.

 

Saw the wedges

Make wedges using the tablesaw (Photo 6). This method allows you to cut a precise angle and fine-tune each wedge’s thickness. Make a wedge blank from straight-grained wood. I prefer one that contrasts in color from the tenon. Make the blank about 3/4" thick and as wide as the mortise.

Tilt the blade to the guide block’s angle. Here, it’s 3 degrees. Raise the blade to make wedges that are about 1" longer than the tenon.

For a trial cut, position the stop block so the thin end of the wedge is the same thickness as the tenon’s kerfs. Clamp the blank to a tall fence using a wooden handscrew. (A wooden clamp protects your blade from damage if you accidentally place the clamp too low.) Flip the blank around to cut a second wedge. Remove the blank and crosscut the wedges by hand or on the bandsaw. File chamfers all the way around the wedges’ thin ends.

 

Test the wedges’ fit

Push the tenon all the way through the mortise—without glue, of course. Tap in the wedges, but not too hard (Photo 7). If they’re too skinny, cut them shorter or adjust the stop block and saw new ones. If your wedges become stuck, pull them out using locking pliers. The wedges should go in as far as possible but not be so long that they hit bottom before fully spreading the tenon. Marking the bandsaw kerf’s length on each wedge will help you prevent this problem.

 

Assemble the joint

When everything is ready to go together, you only have to put glue on the mortise’s long sides and the tenon’s cheeks. Clamp the joint so the tenon’s shoulders are tight to the mortise. Then brush glue into the saw kerfs and the mortise’s tapered spaces. Tap in both wedges and clean up the glue squeeze-out. Saw off the wedge’s excess length after the glue dries. Use a file or low-angle block plane to level the wedges flush to the tenon.

Click any image to view a larger version.

How the Joint Works

Here’s a cutaway view of a wedged mortise-and-tenon joint. Driving in the wedges forces the tenon to flare into a fan or dovetail shape. The mortise is tapered to match the angle of each wedge. Like a dovetail, this joint can’t pull apart after the wedges go home.

This tenon has two unusual features: saw kerfs that create flexible strips and holes that disperse the strain that the wedges create. The wedges cause the strips to bend; the holes prevent the bend from splitting the rail.


1. Make the mortise before you cut the tenon. I use a shop-made template, a drill press, plunge router and two flush-trim bits to make large throughmortises (Photo 2). The hole in the template is the exact size of the mortise.


2. Here’s a cross section of the mortise in various stages of completion. You make it in four steps: 1. Drill out most of the waste. 2. Follow the template with a short top-bearing flushtrim bit. 3. Using the same bit, remove the template and rout deeper. 4. Flip the workpiece and finish the mortise with a bottom-bearing flush-trim bit.


3. Using an angled guide block and chisel, taper the mortise’s ends into a flared shape. The taper leans 3 degrees from square. Make the taper about three-fourths the depth of the mortise. Turn the mortise over and square the remaining corners.


Designing Your Wedged Joint

Each part of a wedged joint must often be tailored to fit the joint’s size, intended strength and type of wood. Make a prototype following these steps:

1. Substitute a notch made with a dado set for the mortise (see “How the Joint Works,” page 2). Taper both of the notch’s sides by angling the miter gauge.

2. Make a full-size tenon. Observe how well the flexible strips bend. You may be able to use smaller strain-relief holes or no holes at all.

3. Experiment with the notch’s angle. The wider the taper, the stronger the joint. My taper is 3 degrees, but you can increase it up to 8 degrees.

4. Test the bend. My flexible strips are only 1/8" thick opposite the strain-relief hole; so they bend easily. Depending on the wood, this thickness can be increased to 1/4" or so to improve the joint’s appearance.


4. Cut a tenon to fit tightly into the back of the mortise, where there’s no taper. On the tenon, draw a centerline directly opposite the point where the mortise begins to taper outward. Drill two strain-relief holes all the way through the tenon.


5. Saw kerfs in the tenon to receive the wedges. This creates strips that can flex without breaking. I aim for the inner edge of the hole so that the kerfs don’t end up too close to the tenon’s edges.


6. Cut extra-long wedges on the tablesaw. Tilt the blade 3 degrees—the same angle as the guide block you used to taper the mortise. Crosscut the wedges from the blank with a bandsaw.

Caution: You must remove the blade’s guard for this cut. Be careful.


7. Test-fit the wedges without glue. You have to get their thickness just right to completely flare the tenon before the wedges hit bottom. Adjust the tablesaw setup until the wedges are the right size. You’re ready for gluing.

 

Sources

Note: Product availability and prices are subject to change.

MLCS Woodworking, mlcswoodworking.com, 800-533-9298, 1/2" Pattern/ Flush-Trim Bit, 1/4" shank, #16509; 1/2" Flush-Trim Bit, 1/2" shank, #17803.


This story originally appeared in American Woodworker July 2006, issue #122.

July 2006, issue #122

Purchase this back issue.

 

 

Mortising on the Drill Press

Mortising on the Drill Press

Simple improvements make a mortising attachment work great.

By Tim Johnson

Purchase the complete version of this woodworking project story from AWBookstore.com.

Even though they’re sexy, benchtop mortising machines aren’t the only power-tool option when it comes to cutting square-shouldered mortises. A drill-press mortising attachment can be just as effective and it costs a lot less. I’ll show you how to tune any out-of–the-box mortising attachment so it’s easy to install and a joy to use.

Mortising attachments are available for almost every drill press. Although they vary in appearance, they all have three basic components: a fence, a chisel holder and a hold-down. Upgrading these parts to stabilize the workpiece and operating the drill press at the optimal speed are the keys to success.


Two-piece mortising chisels cut square holes. The auger bit fits inside the chisel and protrudes slightly. During operation, the auger drills a round hole and the four-sided chisel squares the corners. Cut side by side, square holes create mortises (see photo, above).

Click any image to view a larger version.



This story originally appeared in American Woodworker May 2005, issue #114.

May 2005, issue #114

Purchase this back issue.

Purchase the complete version of this woodworking project story from AWBookstore.com.

 

Mafell Chain Mortiser. Dang.

Mafell Chain Mortiser. Dang.

My least-favorite joint to cut by hand is – hands down – a deep mortise. But when you build a French-style workbench, you need to make about a dozen of them. And if you do it by hand, you are talking about a lot of boring, chopping, paring and sweating. When I mentioned this to Continue reading»
 

Workbench Assembly. With Glue.

Workbench Assembly. With Glue.

Assembling workbenches in the old-school manner is a nail-biter. If the drawbores are too close together, then you drive the peg in and nothing happens. The tenon isn’t pulled into the mortise. You start looking around for your framing nailer. If the drawbores are too far apart, you drive the peg in and it explodes Continue reading»