Large Finger Joints

[Scott Bernstein]

I am making a 6-seater dining room table out of Ash, inspired by the Angela Adams Tulia table. That table is 1 3/4” thick but my stock will be 12/4; final thickness of the table top will be between 2.5-2.75” or so. Legs will also be 12/4 and tapered towards the bottom. Legs will attach to the table top with large finger joints (fingers 2.5-3” long, 3/8 or 1/2” thick). No apron. Table top dimensions around 34” wide and 65” long.

Question is how to make the fingers in the table top.... Stock is too big to fit in my Router Boss and way too tall to orient vertically in the table saw. I figure I can either use a hand-held router with a custom jig, routing with the stock horizontal and the router bit perpendicular to the table top, or my PantoRouter with the stock, and router bit, oriented horizontally. I do have a 3” cutting length 1/2” cutting diameter straight bit that I can use either way. I have used the pantorouter previously for mortise and tenons in very large stock, but never used it for finger joints. Could also get more creative and do a large sliding dovetail with a single finger on either side - in other words a sliding dovetail sandwiched by bridle joints in either side. For that, the pantorouter would be the way to go.

Anyone have any recommendations or other joinery technique I should consider?

SB

[Lee Schierer]

I would think that a regular mortise and tenon type joint would be sufficiently strong for a top that thick.

[Mike Ontko]

Scott, are you referring to this Angela Adams "Tula" table design (pictured below), or something that's more like a waterfall end?
383437

I only have experience with 1/4" and 3/8" finger joints, but for the size you're talking about I would think you could treat the layout and cutting more like you would dovetails. Layout and cut your positive ends and then use those to scribe marks for making the matching negative ends (positive:negative, or A:B, or however you want to label those two opposing sides). I've watched a number of videos on YouTube posted by Ishitani Furniture, like this one: ISHITANI - Making a Shoe Cupboard (https://www.youtube.com/watch?v=zqAQaAYP0y8). The layout and cutting of dovetails begins at 2:08. He uses an industrial sized sliding tablesaw and clamps the cupboard sides vertically to the crosscut fence, but this could be done just as well by hand.

Or, maybe I'm missing the point of what you're asking?

[glenn bradley]

A picture or drawing of the joinery will get you better results. When guessing, things can go quite off course without helping you.

[Patrick Kane]

I imagine a router with edge guide would work well enough for the top. Set your edge guide, route the top, then flip the table top and route the bottom using the same settings. It would be a pain to flip the thing 4-5 times, but should work. I dont think most routers have 2.5-3" of plunge capacity. I would probably approach it another way. I would mill everything for the top and lay out the final glue up arrangement. Take the outside two boards and cut the fingers at the bandsaw. I would cut them longer than 2.5-2.75" to give yourself some play in squaring off the final glueup. Chisel out the waste, and do the same for the legs to get your finger joint done. After you glue up the table top, the extra .5-1" of finger length will let you use a track saw to square up the ends flush with your legs.

$6,600 for an ash table. I would love a line out the door of customers wanting those. I would be a happy man for the next 30-40 years of my working life.

[Warren Wilson]

If you have a pantorouter, why not just ask Matthias Wandel? :)

[Rod Sheridan]

Dovetail saw, drill bit, mortising chisel, mallet...........Rod.

[Jamie Buxton]

I’ve done finger joints like that with the stock oriented vertically on the tablesaw. I have a sturdy cutoff sled, and I added braces to it to hold the workpiece. It is pretty straightforward to hold big stock very firmly and safely.

My shop has a twelve foot ceiling, which helps. If you have a shorter ceiling, pull the saw outdoors.

[Scott Bernstein]

Yes - exactly like that "Tulia" table. I think the pantorouter is probably the best option. I have only 9ft ceilings in my garage and rolling equipment outside into the driveway is not an option. We have a driveway with an extremely steep grade - table saw or band saw would end up in the neighbor's living room. I like the idea of doing all the milling and layout first, then do the finer joints on he pantorouter before glue-up. I lack the skill to use any hand tools, sadly, with enough accuracy for something like this.

As for the price...that's why I'm building it. Even ordering lumber online and paying for shipping I'm doing it for barley a 10th of what they charge - plus mine will be thicker and slightly larger...

Thanks
SB

[Patrick Kane]

I have a source of ash near me that is around $0.50-$1 a bdft for 8/4-12/4. Cost of materials aside, because they arent the best indicator of something's profitability/sale price, that table is just plain simple to build. There arent a ton of man hours in that build is all. I havent heard of the company before, but if they are selling them, then truly good for them. I certainly wouldnt hold anything against a craftsman making a good wage.

A heavy shaper with sliding table would make short work of those joints. the bandsaw and chisel approach wouldnt require much skill with hand tools. Depending on your bandsaw and blade, you should get straight and clean cheek cuts to your finger joint. After that, its just about chiseling the waste out. after the first 1/2" or so of depth, your chisel work doesnt need to be dead 90°. In fact, I would backcut it a bit from the top and then from the bottom to make sure you get a crisp joint where it is visible. End grain to edge grain isnt where the strength of that joint is anyways. Im sure you can find a video on youtube, but you make a shim the thickness of your bandsaw blade kerf, and use that when cutting the corresponding fingers to the joint. Makes the perfect offset for the fingers to come together.

[Doug Hepler]

Scott,

If I understand your question, I would think of these joints as M&T joints. I support what Patrick Kane said in his 2'd paragraph.

As for joinery alternatives, those joints are going to be subject to some heavy loads. You might consider pinning/drawboring the tenons or even using sliding dovetails cut into both faces of each joint. The legs would be easy enough for the tail side. The only way I would know to cut the pins into the top would be with hand tools.

Doug

[Peter Christensen]

That is where a Domino would shine.