I used 1/8” thick acrylic to mold recess in a white concrete table top that could accommodates pieces of 1/8” walnut. I used a laser cutter to make a geometric pattern inlay but the same concept could be used with hand tools. The white concrete table top has a plywood core and is supported on 2 pieces of steel beam. This project cost around $110 and took about 4 hours.

SUPPLIES:

Quikrete Countertop Mix in White
Home Depot
I used Quikrete countertop mix in white to make the tabletop. Quikrete 5000 could be used as a substitute if you wanted a grey table top.


1/8" Acrylic
Home Depot
I used 1/8" acrylics to make the recesses in the concrete mold.


1/8" Walnut
Rockler


Steel Beams
I bought two pieces of a steel l-beam from my local steel yard.

TOOLS:

Rockler Laser Cutter
Available at Rockler









RYOBI Glue Gun
Available at Home Depot












RYOBI Table Saw
Available at RYOBI Table Saw














RYOBI Compound Miter Saw
Available at Home Depot












RYOBI 18 Volt Cordless Drill
Available at Home Depot












RYOBI Orbital Sander
Available at Home Depot

INSTRUCTIONS:

STEP 1: Laser-cut the walnut.
I designed the pattern in Adobe Illustrator and then laser-cut 1/8" walnut that I got from Rockler. I then used the same pattern to cut pieces of 1/8" acrylic the exact same sizes.









STEP 2: Cut the melamine and make the mold.
I cut 3" wide strips of melamine with my table saw and then cut the strips to length with my compound miter saw. I used my hot glue gun to glue the pieces of melamine together to make the mold. I sealed the outside edges with hot glue.











STEP 3: Design the pattern.
I experimented placing the walnut pieces until I had a design that I liked. Once I had a pattern that I liked I removed the walnut pieces and replaced with pieces of acrylic that I hot glued to the melamine.

















STEP 4: Seal the mold.
I used silicone caulk to seal up the molds but I didn't seal the acrylic to the melamine. I trusted that the hot glue would hold the acrylic down light.





STEP 5: Make the plywood core.
I cut two pieces of plywood that fir inside the outer melamine frame with about 2" of spaces between the edges. I glued and screwed these pieces together and then sealed them with 3 coats of minimax polycrylic to make sure that it wouldn't absorb water from the wet concrete. I cut strips of plywood to make supports that would keep the plywood core from sinking too deep in the concrete.

















STEP 6: Mix and pour the concrete.
I mixed and poured Quikrete countertop mix in white. This product is not normally stocked and I had to special order it for pick up from Home Depot. I mixed it in a large mixing tray with a hoe and made sure to push the wet concrete down into all the corners of the mold. I used my orbital sander without sanding pads to vibrate the molds and get out air bubbles. I placed some weight plates on the plywood to keep it from floating up.



STEP 7: Remove the mold.
I wanted 4 days to remove the concrete from the mold. The acrylic pieces came out easily and left a nice clean recess for the walnut.









STEP 8: Paint the l-beams.
I painted the steel beams with white matte spray paint. I had these pieces cut for me at my local steel yard. I drilled holes in the upper flange so that I could screw them to the plywood core.



STEP 9: Set the table top.
We placed the table top so that the plywood core spanned between the pieces of steel beam.



STEP 10: Install the walnut.
I sanded the walnut pieces by hand and then coated them with minimax wipe on poly. I used construction adhesive to glue them to the concrete. It is important not to use a liquid or water based glue because it can cause the thin wood to warp. I placed a smooth piece of marble tile on the walnut to hold it in place while the construction adhesive cured. I glued on the side pieces of walnut and trimmed them with my Japanese hand saw before sanding the flus and coating them with one last coat of miniwax wipe on poly.















STEP 11: Screw on the legs.
I screwed the steel beams to the plywood core.



STEP 12: Seal the concrete.
I recommend using a clear acrylic sealant on the concrete to prevent the table top from staining.







Good luck making your own DIY plywood shelves and please email or tweet photos to @benuyeda or ben@homemade-modern.com If you want to see what we're working on next, follow us on Instagram: @benjaminuyeda and @ijessup. Also check out our book for additional projects, DIY tips and guides.

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