Domino Legs to Table?

[onocoffee]

My friend is working on a white oak slab table for his little daughters and asked me for advice. Instead of mounting plates to screw the base to the table, he was wondering if he could domino them together. I thought Yeah, that should work.

However, as I'm sitting here thinking about it, I'm wondering if that's still a good route. If he glues the legs to the top with dominos do we need to be concerned about wood shift and what happens if/when it does shift?

At the moment I'm thinking that maybe to use dominos to align the legs to the table but no glue - just cut some slots into the lefts and screw those clips to the top to keep them together.

What do you think?

Thanks!

 

[Packard]

I use a tenon machine, not a domino. 

Not enough information.

I would feel comfortable using domino-sized tenons if the legs were attached to a skirt and then to the table top.

Through tenons and wedges are very strong.  But we would need to have the size of the legs.  3” x 3”?

You could use multiple tenons (dominoes) per piece.  Again, not enough information on the size of the legs.  I would guess 3 or 4 tenons per leg.

Luckily Festool publishes a video on how to attach legs to a table.

My tenon machine lacks the throat depth to directly attach to a live edge table top.  I would have to manually drill holes and clean up the rectangle with a chisel.  If I did that, I would add wedges.

 

[ChuckM]

My friend is working on a white oak slab table for his little daughters and asked me for advice. Instead of mounting plates to screw the base to the table, he was wondering if he could domino them together. I thought Yeah, that should work.

However, as I'm sitting here thinking about it, I'm wondering if that's still a good route. If he glues the legs to the top with dominos do we need to be concerned about wood shift and what happens if/when it does shift?

At the moment I'm thinking that maybe to use dominos to align the legs to the table but no glue - just cut some slots into the lefts and screw those clips to the top to keep them together.

What do you think?

Thanks!

This video (just an example that popped up on a Google search, you can find tons of how to fasten a table top to its base videos on YT) shows the use of z fasteners:


(If your friend prefers articles, here's one example:https://canadianwoodworking.com/techniques_and_tips/table-tops-and-wood-movement/)

Here is how cabinetmaker's buttons can be used in place of z-clips:https://www.festoolownersgroup.com/...ino-to-attach-table-tops/msg727259/#msg727259

Bottomline: if the top is wide enough, plan for wood movement unless manufactured materials are used.

 

[Birdhunter]

I always use something that I call Z clamps. I think Woodcraft calls them table top fasteners.

 

[Lincoln]

No, wouldn't do that. Use the Domino to cut slots in the rails/stretchers, then use metal clips to attach the top. Or, make wooden ones.
https://www.core77.com/posts/71864/...-Using-Cleats-or-Buttons-to-Attach-a-Tabletop

 

[onocoffee]

Since I was only working off the pic I showed you, I don't have the actual dimensions. What you saw in the pic is as much as I know about the table.

I did speak with my friend this morning about it, so we'll see how it turns out!

 

[smorgasbord]

Since I was only working off the pic I showed you, I don't have the actual dimensions.

I don’t see a picture/photo from you

 

[onocoffee]

[member=77266]smorgasbord[/member] Gosh, I thought that I had put it up with the post! No wonder Packard was like "Not enough information"!

 

[Vtshopdog]

Just a thought:

It looks very heavy despite the small (maybe built for a toddler??) size. I’m concerned the table as pictured is top heavy with a fairly narrow footprint and subject to being pulled over on top of a smaller child.

Or maybe it’s more stable than I perceive?

 

[smorgasbord]

OK, so just narrower slabs for legs directly into the top.

I would think using two rows of dominos across the top of each leg (going the full 25mm depth on each) would work - 10x50s or 8x50s if the stock isn't as thick as it looks. Note that there isn't a stretcher between the legs, so the forces to worry about are the ones trying to rotate the legs towards or away from each other; hence the two rows.

I do think [member=68668]Vtshopdog[/member] 's worry about tipping over is valid, though. The weight of the table may help, but then if it does tip that would be dangerous. If she stood on the long edge of the table, would it tip? My son when he was young would climb on everything in his room.

 

[Packard]

With really robust understructure as pictured, the only real concern is side to side racking.

With tenons (or Dominoes) the side to side racking with one (1) row of tenons will have one edge in compression and one edge in tension when subject to racking.

With two rows of tenons, one row is in compression and the other is under tension where there is side to side racking.  Two rows will be stronger—provided adequate glue is used.

Also, the rows should be separated as much as possible.  I will defer to actual Domino users as to how close to the edge to put each row (and how many and what size dominoes to use. 

If this were being built in my shop (basement), I would use really large diameter through dowels.

I would first glue and screw the pieces together.  Once the glue had set, would back out one screw and drill for the through dowels.  I would be inclined to use 1” or 1-1/4” depending upon the thickness of the slabs.  I would repeat until all the screws have been replaced by dowels. 

You can add wedges to the dowels, though I doubt it will be required.  Use generous amounts of glue for the dowels, trim and sand. 

I may be the only member of FOG that likes the appearance of through dowels.  It reminds me of well-made chairs.

Addendum:  Every place I used “tenons” you can replace with “Dominoes”.  I consider Dominoes a very efficient form of cutting mortise and tenon joints.

And, my mortise machine mostly collects dust.  I did use it recently to make toy “Leica” cameras as I wanted a square “viewfinder”. [big grin]  But that hardly counts as “cutting a mortise.”

Fast forward to 5:20 to see how to drill for the dowels.

Fast forward to 7:20 to see the final appearance of the dowel joint.

1/3 the slab thickness for the dowel diameter.

This guy uses clamps.  I found that the single screw at each dowel location + glue works fine and is more efficient. 

With through dowel joinery you never have to worry about alignment of the tenons.

Note:  I am not saying that this is better; I’m saying that this is how I would assemble the bench.


Addendum #2:  I should probably mention that the through dowel construction was lifted from a Roy Doty column in Mechanix Illustrated (“The Wordless Workshop”).  Doty died about 10 years ago.  His column was well-regarded by beginning woodworkers.

 

[Crazyraceguy]

That's kind of a combination of dowels and huge box joints. Everything is opposing, so it must be pretty strong.

 

[Packard]

That's kind of a combination of dowels and huge box joints. Everything is opposing, so it must be pretty strong.

Yes, a very strong joint.  And fairly easy to do.  You only need for all the boards to be exactly the same width and length. 

Then assemble the boards to make the planks with the exact same offset.  With any luck, it will make a nice tight joint without any hand-fitting. 

The dowels are probably not necessary.  All the benches at the recently remodeled Apple Store were made that way without any dowels.  I’ll bet you could take some 2” x 6” fir studs and rip them all to about 5” (best done at a single setup) and come up with a sturdy bench.

I only offered the video to show what the 3/4” or 1.0” diameter dowels would look like.  The O.P.’s photo of the table top and the legs would have the legs inset more, and not likely to work as the same way. 

I think 5 or 6 one inch diameter dowels would be sufficient.

When I did it, I did not saw off the ends of the dowels.  I cut the dowels to length first and drilled about 1/2” deeper than necessary.  I added the glue to the holes and tapped the dowels in by hammering down a block of wood.  The wood prevented accidental hammer strikes on the surface and I taped on some cardboard that would leave the dowels about 1/16” proud of the surface.  I sanded them all level to the surface.  No sawing required. 

But…If I drove one too deep, it would have been a problem.  The wood block prevented that.