Looking for some process advice for a tusk tenon

[brian zawatsky]

Hey guys. I don't post much in the Neander forum, as I slipped on a banana peel and fell headfirst into the bowl turning vortex about a year and a half ago. I hate to admit that my planes, chisels, and saws gathered some dust, but hey, nobody's perfect.

So anyway I really enjoy hand tool woodworking, and I've managed to crawl my way out of the vortex long enough to begin construction of a trestle style dining table, out of cherry.

I'm going to try and post some pics, but I'm on iPhone at the moment and I'm not sure that I'll be able to pull it off.

[brian zawatsky]

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So this is where I stand right now. I'm having a tough time uploading pics, and forum runner doesn't play nice with iPhone 7, so I will have to wait until tomorrow and post pics from my laptop which is currently on my desk at work.

My my plan is to utilize a tusk tenon on the stretcher, which I have yet to mill, and lock it in place with a wedge in an angled mortise cut thru the tusk tenon.

Do do you guys have any advice on how to cut the angled thru mortise for the locking wedge? I want to keep it as tight and true as possible, and I've never used this joint before.

[Reinis Kanders]

Roy Underhill just recently had an episode about tusk tenons and also how to cut the mortice. I am pretty sure it is somewhere on PBS for free. Basically one just chisels it out. One could also use an angled paring block for the final cuts to make sure it is perfect.

[Robert Judy]

Maybe this would help: http://www.renaissancewoodworker.com/shop-update-live-2-kinds-of-tusk-tenons/

[David Eisenhauer]

Basically, fab up your tusk first by shaping a very shallow angle on the thickness of your tusk, then use the shaped tusk laid up against the face of the leg (tusk face up, just as it will be inserted as the pattern) to scribe the shape of the tusk mortise on the protruding edge of the stretcher end. Position the shaped tusk for scribing across the protruding stretcher end at an approximate half-way insertion or slightly less (where you want the tusk's final tightened position to be) position when you are ready to scribe. You can use a bevel gauge to transfer the scribed lines on the end of the protruding stretcher end lines down to the desired position on the protruding stretcher end for the tusk mortise. It is recommended that the tusk angle be very, very shallow to be best effective. I just described the basic procedure for a horizontal tusk that runs through the protruding leg stretcher at 90* to the stretcher end.

[Kevin Hampshire]

Brian, Before you get too far, you may want to shape a mock up of your tusk tenon and see if it interferes with using the table. Based on your pictures, it looks like a long tusk tenon could be a serious shin knocker for anyone seated at the ends of the table.

[Nicholas Lawrence]

Brian Holcombe has a nice blog and has used wedged tenons on a number of his projects. It is probably worth a look.

[brian zawatsky]

Thanks David. That's basically what I had in mind, just wasn't sure of the particulars.

[brian zawatsky]

Kevin, that's a good point. I will mock it up first; it may even help to prevent me from ruining a nice piece of 8/4 cherry haha.

The legs aren't yet attached yet to the underside of the table, so I can play with the placement to some extent to make everything work. It's 42 x 84, so it can seat 6 comfortably. I just have to get the leg assemblies positioned correctly.

[David Eisenhauer]

Very nice looking table by the way. More photos please.

[brian zawatsky]

I brought my laptop home, so I can upload some more pics.

As much as i like working with hand tools, I also like to actually complete things. The amount of free time I that I have to devote to the craft is not nearly as much as I'd like, so I find myself making cost/benefit decisions with respect to how to approach tasks for a given project. Call it the economics of time management i suppose.

That said, I dimension nearly all my stock by machine, and did use a router for several parts of this build. Anyway...

I started the table at work, since I work in a commercial shop and it was just easier to manage there. To keep the glue up simple and stress free, I made two slabs and then joined them in the center with a spline.
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[brian zawatsky]

I used a straight edge and a router to define the shoulders of the breadboard tenons, and removed the balance of the material with a jack plane. Then i used a carcass saw to cut the 2 remaining shoulders and rip the tenon down to size. Followed by a No. 4 1/2 and a scraper plane to smooth out the top. As I'm sure you guys know, flat sawn cherry can be a real pain to work with a hand plane. I tried to stay away from the 112 as much as possible, but there were spots that I just couldn't get to behave with the smooth plane.
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This task done, I moved on to the breadboard ends. After milling the stock a fuzz oversized, I laid out the mortise, drilled out the waste with a forstner bit (in a cordless drill :D) and pared the walls clean. After a bit of fussing with the tenon thickness and a few adjustments to the shoulder, the breadboards were fitted to the table top.

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[brian zawatsky]

This completed, I drilled through the breadboards, slipped them back on, and marked the tenon to be drilled for the drawbored walnut pegs. The holes were slotted to allow for seasonal movement and offset from the breadboard holes by 1/32". This may not seem like much of an offset, but it was plenty to pull the breadboard up tight to the shoulder. Any more and I would have split the tenon trying to drive the pegs in. Applied glue to the center 12" of the breadboard/table joint, and just a dab to the ends of the pegs to lubricate them a little, then slammed the pegs home & cut them off flush. That part was nerve wracking!! I kept waiting to hear a cracking sound as the tenon split or my breadboard end let go. Fortunately everything went smoothly. Then I planed the breadboard flush with the surface of the table.

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[brian zawatsky]

Once both breadboards were installed and the entire top was smoothed, I got some finish on it to protect it from any moisture in my basement shop & keep it stable. My wife wanted an "antique" look to the table, so I used multiple applications of medium walnut Danish oil, which produced a nice deep tone that we are both pleased with.

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[brian zawatsky]

I cut the pattern for center of the leg assemblies on a CNC router at work which is about the furthest possible point from Neanderthal woodworking. Sorry, just being honest. Rough cut the leg blank on the bandsaw, and used a router to finish them up.
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[brian zawatsky]

Ok, back to the hand tool world. The top and bottom pieces of each leg assembly were cut from 12/4 cherry we had left over from an architectural job at work. Mortises were drilled out with a bit and brace, and finished up with chisel & mallet. Tenons on center legs were tuned up with a shoulder plane & No 65.
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So thats where the build stands for now. I'll update the thread with more (hopefully successful) pics of the stretcher tusk tenon process. Thanks for looking!

[Brian Holcombe]

That's very nice work Brian! Often the name tusk tenon is applied to a through tenon with wedged key, it's not a traditional tusk tenon as would be used in timber framing. I don't mention this to be the forum know-it-all, but for clarity in providing advice on how to proceed since the two joints are cutout differently but work on the same principle.

[Pat Barry]

That's a great looking table top. Very nice work!

[David Eisenhauer]

Your method for attaching the breadboard end is the method I have used over the years, but lately during my You Tube surfing, I am seeing that some folks do not run a continuous full-length tenon on the end of the top but, instead, cut out sections of the tenon to create a "gap-toothed" look with separate, corresponding mortises for each "tooth". Sometimes the full-length tenon has sections completely removed to create the gap-tooth look or sometimes a short stub tenon is left in place between the full length sections of the tenon (I guess to ensure that the breadboard end stays lined up across its full length). In the case of the stub tenons, of course the mortise runs the full length of the breadboard. Sometimes each tenon coincides with the individual board that was used to glue up the entire panel. Can you or anyone comment on a preferred method or the plus-minus of the various methods?

[brian zawatsky]

I have seen this gap-toothed looking tenon that you're referring to, David. I just don't get it. The only possible advantage I could see to doing that is it would make your mortises smaller. Cutting that one big long mortise is kind of a PITA, but having one long tenon in a single mortise seemed to be the strongest and most sensible option to me. I left about a half inch of empty space inside the length of the mortise to allow for expansion of the tenon, so that is a non-issue.

[brian zawatsky]

Got to spend some time in the shop this afternoon. Milled up some stock for the stretcher, and started a mockup of the joint with the off cuts.
I don't have a joinery saw large enough to cut a 5" long tenon, so I ended up using an old 28" 6pt Disston no 7 lol! I can honestly say that I have never attempted to cut joinery with a big ol rip saw before. It was a ton of fun

I love hand saws. I mean, really love hand saws. My wife thinks I have a problem, and she's probably right...



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[brian zawatsky]

So after cutting the shoulders, I cleaned up the tenon cheeks with a shoulder plane and some paring cuts with a sharp chisel. The surface of the tenon wasn't too bad, considering how coarse of a saw they were cut with. Then I cut a thru mortise in another piece of scrap. Totally forgot to take pics of that process, but it was pretty simple. Marked out the mortise on both sodes, drilled out the waste with brace and bit going in half way from either side, then chopped & pared the walls smooth.

Mental note: next time, dont spend too much time making the tenon look pretty until fitting it to the mortise. Duh.

Next shop session will be to make the wedge and cut the angled thru mortise in the tenon. Thanks for looking, and thanks for the nice comments guys! Seeing some of the work that you guys post here makes me feel like a hack lol!

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[Stewie Simpson]

Brian; looking at some of the contents within your tool bag (shown within the 2nd photo on your previous post), there is a fair chance your an Electrician.

Stewie;

[brian zawatsky]

Stewie, actually I am a mechanical engineer & CNC programmer in a commercial cabinet shop. Every once in a while they'll turn me loose from the shop and send me on an install, and that is my install bag. Sticking out of the outside pockets are a bunch of screwdrivers and my beater Buck Bros chisels.

[Stewie Simpson]

Sadly the Cabinet Makers trade has been dumbed down over the last 10yrs to just screwing cnc cut panels together, and installing them as completed units.

I know of a great number of qualified Cabinet Makers local to the area in my location that have just up and moved away from their trade because they are not being asked to utilize the skills they were once trained for. One can only smile and mumble to ones self at the good and the bad that comes out of an industry being forced to adopt high tech modern practices to compete for any work. Putting that aside, look forward to following your projects progress.

Stewie;

[brian zawatsky]

Yeah, sad as it may seem there is really no other way to stay in business when your competition comes from a country whose workers make less in a day than I do in an hour.

Also, anyone's opinion on the issue notwithstanding, my job allows me to make a good living. I would challenge any cabinet maker to keep up with the mental gymnastics that it takes to solve some of the problems that I encounter on a tough day, especially without a college degree or formal training. I came off the bench when I saw the opportunity to grow a new, useful, marketable skill and haven't looked back. It's the way of the world, unfortunately. Change or die.

That's what my basement shop is for, and why I choose to fill it with century old hand tools. Doing my little part to preserve the integrity of the craft, however insignificant it may be.

[Karl Andersson]

I used large tusk tenons on the stretchers for my workbench - they have held the base tight for years with no adjustment needed. The angle is pretty shallow by necessity (a sharper angle would likely work loose easier), so after I drilled out the majority of the waste, I was able to chop the mortises square and put the angle in using marked lines on top and bottom and chopping in from each end first, then paring it smooth. A bevel gauge helped "true' the chisel angle occasionally.

When sizing and placing the mortise for the tusk (wedge), don't forget to make the baseline - the flat, vertical side of the mortise closest to the shoulder of the stretcher- closer to the shoulder than the width of the leg you are piercing. This will prevent the tusk from bottoming out in the mortise before it can really pinch the leg, especially if the leg shrinks in width with age. I made mine so the vertical mortise was about 3/32 below the surface of the legs.

If you're worried about the protruding tenon, you could consider two smaller horizontal wedges (flat or conical) like some Arts and crafts furniture makers used. Using two smaller wedges can allow you to make the tenon protrude less. Look up designs by Charles Limbert in particular - they used square and conical wedges.
good luck,
Karl
my bench:
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[brian zawatsky]

Sorry for the delay, haven't had time to post!

The wedges were cut from a scrap piece of 10/4 walnut that I had laying around. Resawed into 3 pieces, laid out the wedge shape (selecting for straight grain to make planing easier), and cut the mock up wedge.
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The wedge mortise was laid out using a sliding bevel that was already set from laying out the wedge. Then simply drilled out waste and chopped & pared the mortise clean
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Used a batten and holdfasts to plane the wedge to size
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Assembled test joint :)

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[brian zawatsky]

Before cutting the tenons on the actual stretcher, I thought it might be prudent to give the old "One Son" rip saw a bit of attention. Just a light jointing and a couple file strokes on each tooth did the trick. Cut much faster after sharpening.

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This chore complete I cut the tenons. This was a bit trickier than cutting the mockup, simply from a work holding perspective. I learned that my next bench will be MUCH heavier than my current one, and that it will have a tool trough to prevent this mess of clutter lol

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Drilled and chopped mortises in legs, cutting in half way from each side

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Stretcher in place. Planning on cutting a slight elliptical arch on either side of the stretcher to give it some character, and better make it match the legs. I'm hoping to get some finish on it all this weekend.

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[Robert Hazelwood]

That's a nice table, cleanly executed. I need to build myself one of these...

[David Eisenhauer]

Great looking table Brian and I would think that adding in slight curves to the stretcher would be even better. Nice work on the tusk. I have only done two of these tusks before, many years ago now, and cannot recall the construction details of the tusk. I do know that my tusks were angled somewhat less than yours is (apparently) because I was told/read that much angle at all would result in loosening over time. What angle or vertical offset did you use for your tusk?

[Matt Evans]

Looking good so far. . .

[Jerry Olexa]

.Brian, nicely done!!! Thanks for posting the pics.....