Introduction: Piano Coffee Table
If you can find an old piano that is beyond repair - they're constantly being given away for free on Craigslist - and you have a few basic tools, you can build this coffee table! On behalf of musicians everywhere, please don't tear apart a working instrument!
This project is simpler than it may appear... you don't need to be a professional carpenter and you don't need a fancy workshop... just some patience and willingness to learn along the way. All the wood is pine, which is not ideal for furniture, but works well enough if you're on a budget. You will also notice that the measurements are described as "approximate," not because reading a tape measure is difficult, but because it's okay if your lengths are not exact, as long as they're identical to the opposing piece.
4 Queen Anne table legs (I bought mine from Lowe's)
1"x4" for the table top (two lengths approx. 48" and two lengths approx. 24")
1"x3" for the apron (two lengths approx. 44" and two approx. 20")
1"x2" strips for the supports (one length 46" and two lengths 22")
1/4" thick plywood, approx. 46"x22" for table bottom
tempered glass, custom cut
sandpaper (120, 220, 300 grits)
Verathane Dark Walnut stain
Kreg pocket hole jig
paintbrush (for stain)
cotton rags / old t-shirts
foam brush (for polyurethane)
Credit where credit is due: I got a whole lot of inspiration from this instructable. Thank you!
Step 1: Somewhere, Beyond the Pine
Notice that the corners of the table are mitre cut (45º). That gives the shadowbox a picture frame kind of look. The first thing to do is to take the four pieces of 1"x4" and glue them together to form the table top. It is important to apply even pressure when glueing a frame like this, and weigh it down to prevent bowing. Since I don't have a large workbench and huge clamps, I got creative and used my dining room table for the glue-up. 223 ammo served as my weights. If you're using the inside of your home as a workshop like me, be sure to put some wax or parchment paper down at the corners for the inevitable glue sqeeze-out.
Step 2: You Ain't Never Cut a Rabbet, You Ain't No Friend of Mine
Using a hand-held router, cut a 1/4" x 1/4" rabbet into the inner frame for the glass to sit in. Alternatively, you can make a few passes on a table saw prior to the glue-up. This is also a good time to start sanding with 120 grit and knock down the outer edges of the table. Do not sand where your rabbet is cut, as this may weaken the support for the glass top.
Step 3: Holy Pockets!
Using the Kreg jig, drill pocket holes into the inner part of the apron. You will need holes facing the legs, as well as holes facing the table top. You will also want to sand what will be the bottom of the apron to just soften the edge a bit.
To assemble the table, lay the table top upside down (rabbets facing the floor), then lap the legs in each corner. Put the aprons in position, checking to see that it sits flush to the table top as well as the legs. Begin by applying wood glue and screwing the apron to the legs, checking that it's perpendicular to the table top. I found that it was easier to attach each side to the legs, then the top, prior to moving on to the next side. You may prefer to assemble the entire perimeter before attaching it to the top, but if you do so, make sure you're constantly checking to make sure the whole setup remains flush and square.
Step 4: Somewhere Over the Stainbow (ok, That's a Stretch...)
Once initial assembly of the table is complete, sand everything down to 220 grit. Give the whole table a wipe down with some mineral spirits or denatured alcohol on a rag. That will clean off any remaining sanding dust before you begin staining. Be careful on the corners of the table top... always move your brush in the direction of the grain, unlike my mistake in the photo. If you're unsure of your brush technique, it might not be a bad idea to use blue tape at the corners. I would tape off the area on the inside of the apron where the support beams need to be attached (next step) so that the glue can adhere to bare wood.
An important lesson I learned is that wood stain is not like paint... do not leave excess on the surface. Brush it on, give it a few minutes, then take an old cotton t-shirt and wipe off the remaining stain. Leaving it on will not make your wood darker, faster... it will, however, leave you with a sticky mess that hides all the beautiful wood grain. This is where the patience kicks in. Stain it, let it dry according to directions on the can, then gently hand-sand it with 300 grit, following the direction of the grain. Repeat twice (3 coats total).
A note about those rags: Wood stain, if thrown away wet, can cause a spontaneous fire in your trash can or dumpster. Don't do it! Lay the rags out in the sun to dry completely, and only when they feel hard is it safe to toss. You'll want to check with your city to find out if they want that in the trash or at the hazardous materials collection site.
Step 5: Let's Get to the Bottom of It.
Use the router again to cut dados in the support beams to create lap joints (some call it a "cross halving joint"). Drill pocket holes to all the ends. The plywood for the bottom was sanded and stained prior to attaching it. Sorry that I didn't take a photo of this, but you have to cut out notches in the corner of the plywood so that it can fit around the legs. I used a scrap piece of cardboard and cut it to form a template.
Lay down a blanket and flip the table over. Drop the bottom into the space, then apply glue all along the side of the support beams that will face up. Now it's a race against the clock before that glue sets. Apply glue to the sides of the supports where they will meet the apron. Install the supports using pocket screws, and immediately flip the table back over. Gently press down on the table bottom and add a little bit of weight to "clamp" it for the glue to set.
Step 6: The Key to This Is...
At first I thought it would make it easier to handle the keys if they were glued together in small groups. This is a bad idea. Since the keys of a piano are meant to move freely without rubbing up against each other, they need a small gap in between to be laid out in a straight line. More tedious, yes, but it's necessary to glue each key individually for the keyboard to look right. It turns out that I was missing key #21, but that was a happy accident that gave me a "rule of thirds" point of interest in the final product.
I suggest that you do a dry fit of the keys and use a ruler to give yourself approximate targets for the keys. Weigh them down to provide pressure on the glue ups.
Step 7: 'Tis the Season for Some Poly.
Since it is a table (which means it will get used), I suggest oil-based polyurethane. To avoid brush lines in the finish, thin the poly a little bit with some mineral spirits or paint thinner (approx 80% poly and 20% spirits) and use a foam brush. Avoid overworking it. Get it on there, maybe clean up a stroke real quick, then let it be. The more you fiddle with poly, the more likely it is that you will leave brush strokes, which means you're creating more work for yourself.
Use 300 grit sandpaper and gently sand in between coats, following the wood grain. It will get very white and cloudy, but don't worry... that goes away with the next coat. Give it a good wipe down with a rag between coats. I suggest three coats minimum.
Step 8: Ta-da!
I know nothing about glass, so rather than risking taking a slightly wrong measurement, I took my whole table into the glass shop. Probably overkill since I know how to read a tape measure, but given that it fits perfectly flush, I think it was worth it.
Enjoy the project! It makes a perfect piece for the music nerd like me.