Introduction: Walnut and Concrete Table With Floating Shelf

About: I work wood but I also have studied chemistry

Hello everyone!

Here's the story of how I built a walnut grilling table table with a concrete countertop for my very old neighbour and his mentally ill wife.

The walnut is from a tree he milled on his farm a few years ago, and I was glad that I could make something for him with it, as he is not at all capable of using tools any more.

As you follow along, and if you're considering attempting something similar, please remember that there is always more than one correct way to do things and that what matters (unless you're working for a commission) is how you feel about your work during the process and in the end.

As Leo Sampson Goolden put it wisely (paraphrased grossly) "The result won't be perfect whenever you work with wood. You just have to bring your work to a certain standard, and knowing what that standard should be is a big part of being a shipwright" Well I am no shipwright but this really applies to woodworking in general, in my opinion. Enough blabbering, off we go!

Supplies

Tools (all joinery cut by hand, but it could be done with power tools and jigs)

Jack plane

Block plane

Workbench with decent work holding capabilities

I would have really been more precise with a jointer plane, but didn't own one back then...

Set of chisels

Table saw (optional)

Marking gauge

Marking knife

A big old mallet for joinery, and a small young mallet for precision stuff

Hand saws, rip and cross cut

Measuring tape, pencils etc.

Power router or router plane

Sharpening stones

Materials

Rough sawn hardwood, amount depends on dimensions

One bag of countertop concrete mix should yield a 2*4 ft slab, about 1.75 to 2 inches thick

Melamine and screws for the concrete form

Concrete sealer, water based

Your finish of choice (as the table was meant for the outside, I used an outdoor UV-resistant varnish)

Optional - epoxy to protect the feet

Sandpaper, glue, etc..

Step 1: Knock Down the Wood to Rough Size, Hand Plane Everything!

Alright so here is a big tall 30 mm thick board of Walnut.

Now back when I built this table I had not yet made a friend who owned a band saw, planer and jointer etc...

So yeah table saw and hand planing it is.

I first roughly ripped the wood on the table saw.

Wood prep by hand is quite daunting, aerobic and boring but it is much less so of all those things with a consistent workflow.

Following Chris Schwarz's advice, I bring my stock to s4s in the following manner. At this point, the lumber is cut slightly oversize in length (1 inch) and width (1/4 to 1/2 inch)

1) make one face flat, checking for highs and lows with a straightedge and winding sticks

2) bring an edge flat, fair and 90° exactly to this face, mark both as they will be our references for laying out joinery later

3) with a marking gauge, find the lowest thickness and mark that dimension all around the board, referencing off the flat face


4) bring the opposing face down to that line

I then cut the lumber to final length and width, clean up the remaining edge to 90° and am ready to lay out joinery

Step 2: Glue and Taper the Legs

The legs are made of two laminated pieces to reach a square-ish profile. I mark the grain direction and glue them overnight, then bring them to s4s with my jack plane.

Then, using a home-made leg tapering jig, I taper off what will be the two outside faces of the legs and mark them

Amateur tip: don't forget to mark the grain direction on legs to avoid glueing pieces in a way that runs grain in opposite directions on the same face - this makes the piece impossible to plane without tear-out!

Step 3: Joinery for the Frames: Tenons...

The main joint in this build, of which you will end up cutting 16 (good practice!) is a simple mortise and tenon joint.

After cutting all the lumber to precisely its final dimension and checking for square once more, we are ready to lay out the joinery.
I like to lay my tenons out first, and I make them a hair wider than the chisel I will use for chopping out my mortises. I choose the chisel that brings me closest to 2/3 or 3/4 of the thickness of the board. This avoids awkwardly looking for a chisel once the tenon is cut and still allows a bit of room for error, as I will need to plane a few fractions of a mm off the face of the tenon for it to fit, enabling fine tuning of the joint.

I mark my tenon using my marking gauge, overall length is about 2/3 of the width of the board, and depth about 2/3 of the width of the piece that will receive the matching mortise. I like to leave a haunch on the tenons that go directly under the countertop to provide more support for the joint vs. torsion forces, but this is not necessary.

I cut the tenon cheeks off, using my ripcut saw right on the outside of the line that delimit the tenon length and width, then my crosscut saw about 1 mm from the tenon depth lines. I then clean up to the line with a chisel.

After the tenons are cleaned and checked for square, I chamfer the end of them to ease bottoming them in the imperfect mortises I'm about to chop out right after I'm done with my beer :)

Step 4: ... and Mortises

The mortises are laid similarly to the tenons, but no depth can be marked. Instead, using the chisel I used to lay my tenons out, I tape the depth on my chisel to know when I have reached a sufficient depth in the mortise.

The great Paul Sellers has a neat video about tenons and mortises - if you don't have a router plane (like me) you can use a shoulder or block plane and wide chisel to clean tenon faces

I try and fine tune my joints as I make them to make sure that I will know what is binding up where during assembly

If you do the last two steps 8 times in a row, you end up with neat looking sides!

Step 5: Sides Are Done!

Are you tired of mortises and tenons?

Great!

You get to do it all over again, 8 of them, for the long stretchers that join the sides. Woohooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo

Okay if you've been making this as you read, you are now your local expert on mortises and tenons.
How do you feel, dear reader?

Step 6: Making Slats for the Bottom Shelf

Now that we have all the frame components ready and the joinery cut, let's work on the bottom shelf.

I should have probably built this a little differently, using thinner walnut to lighten the weight of this whole enterprise but honestly the thought of hand planing 3/4 of an inch off of each one of these slats gave me blisters, so I just did it like so:

I chopped a bunch of wood to the average distance between my bottom stretchers plus 1 inch, and planed these to s4s (aaaaaaaaaaah blisters, but also hmmmmmm muscles)

Then, I routed some reliefs on the ends to fit in a 3/8th inch groove in my bottom stretchers.

I set the depth of the router bit at 1/2 inch, taking effectively 1/2 inch off each side so that the distance between these two rabbets would be exactly the distance between my bottom stretchers.

Step 7: The Stretchers Are Feeling Groovy

Using the top of the stretchers as a reference, I ploughed a 3/8th groove all along the length to accommodate the rabetted ends of my slats The groove is slightly deeper than the rabbets are long, to accommodate for imprecisions and wood movement, and to make sure that the up side of the slats matches the stretcher perfectly flat

The keen observer will see on the picture that tenons and mortises drove me crazy so I skipped two to do something else for a while...

Step 8: Assembly!

Oh, to be at this stage, dear reader.

Everything is neatly arranged and labelled, the joinery is snug, the sun is shining, and all that's left is the part that some people coming back from a Swedish furniture superstore might call "bUiLdiNg mY OwN fUrnITuRe"

That step is assembly.

I started by assembling the sides and glued them overnight. Then I glued all 4 stretchers to one side, using the other to keep them straight but not gluing them in there just yet.

After the glue cured overnight (again..), I removed the not-so-glued side and started installing the slats, spacing them with little piece of walnut made from offcuts. Everything was glued as I went, then I glued the other side on and let t cure... Overnight... Patience is being learned, but it's so slow!

Step 9: Adding a Floating Shelf Part 1

At this stage, I liked the frame a lot but wanted something a little less generic, a design input of my own of sorts.

Now, this design for a shelf probably exists and has for hundreds of years but I have not looked it up and I won't because I came up with it by myself and please let me have that!

Using a half-lap joint, I added two rails to support slats in the same configuration as the bottom shelf, about 2/5 of the way inbetween the top and bottom stretchers.

I made sure to use the inner side of the leg as a reference for leveling these half lap joints, as the outside faces of the legs are tapered.

Step 10: Adding a Floating Shelf Part 2

I then ploughed a groove and prepared the exact same slats I did for the bottom shelf, with the only modification that both the end slats' rabetted ends were trimmed a little bit to hide the groove (see pictures, I'm having a hard time describing this right now)

The half lap joint and slats were all glued at the same time, and I stamped my name on the shelf because I was proud of my work, and also because the next step is....

Step 11: Finishing and Final Touches for the Wood Frame

... Finishing! Here, the first thing I did as I knew this table was going to sit outside was cast a sacrificial layer of epoxy on the feet of the table. This helps with two things: dragging the (very heavy because concrete) table is much less likely to split the legs, and epoxy will prevent water from seeping in and rotting the wood.

I also gave a subtle chamfer to all sharp edges with a spokeshave (you can use a block plane or sandpaper) to prevent splintering in case of encounter with sharp knees.

Then I applied my finish by following the directions on the can.

Step 12: Casting the Concrete Countertop

Okay now this is less woodworking than I'm used to, and my first concrete pour so please bear with me.

Any comments and tips are welcome!

I first built a form out of melamine (error numero uno - I thought I could join two narrow pieces for the bottom but this ended up giving me a nasty line down the middle... Don't be like me, use a wider piece) I mixed a whole bag of countertop concrete with the recommended amount of water and poured it all in two halves in the form. In between the two halves, I added a layer of chicken wire style concrete reinforcement mesh, to help keep it integral. I tapped with a rubber mallet to get bubbles out the best I could and covered it with a plastic tarp to keep it moist as it cured over 48 hours (I learned that concrete needs a water layer on top of it to cure properly, make sure it does not dry out! Error numero dos was setting up a box fan to dry it... I changed that about an hour in)

Step 13: Sanding and Sealing the Concrete

After two days, I asked for a strong woman's help and we flipped the concrete on some trestles.

I wet sanded some rough spots, and loaded it in a truck to bring to its final resting place!

There, I propped the concrete slab on trestles again and applied a few layers of water-based concrete sealer over the course of a sunny day. I then slid the slab on top of the frame. I thought I would need to fasten it to the table but quickly realized it was not going anywhere...

Step 14: All Done!

If you've made it this far, thanks for reading!

I'd really appreciate a vote in the woodworking contest, and please let me know any questions, I'd be happy to help with what little ability I have
Until next time,

Deluges