Concrete Stool

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Concrete Stool
Jeff Farris

Normal concrete has to be poured at least 3 1/2 inches thick or it will crumble, but countertop blend concrete mix can be poured as thin as 1 1/2 inches. This characteristic opens up lots of possibilities for using concrete in all sorts of projects, like this stool seat with an inlaid bottle cap design. A thin pour doesn't require a heavily reinforced mold. Even a cardboard box will work, and the perfect size box for a stool seat just so happens to be an extra-large pizza box.

Things You'll Need
Jeff Farris

Things You'll Need

You can find the supplies to make this stool at your local home center. Plus, this project gives you an excuse to order an extra large pizza and crack open a few beers. You'll need: Countertop blend concrete mix, 14 inch by 14 inch wire mesh or poultry netting, an extra large (16 inch) pizza box, bottle caps, duct tape, contact paper, 2 by 2 boards 4 feet long (4), 1 by 3 boards 6 feet long (2), miter saw, pocket hole jig, drill with pocket hole bit, 1 1/2 inch pocket hole screws, pocket hole plugs, "L" brackets, concrete screws, wood screws, paint and varnish.

Prepare the Mold
Jeff Farris

Prepare the Mold

Cut the lid off the pizza box. Reinforce the four sides with a couple tight wraps of duct tape. Line the edges and bottom of the box with self-adhesive contact paper to keep the cardboard from falling apart when it gets wet. Set the box on your work surface and surround it with the 2 by 2s that will be the legs of the stool. Clamp the 2 by 2s to the work surface, adjusting their positions until they are fully supporting the sides of the box without distorting it.

Lay Out Your Bottle Cap Pattern
Jeff Farris

Lay Out Your Bottle Cap Pattern

Design the layout for your bottle caps on the inside of the lid you cut off earlier. The 10 by 10 grid shown here has approximately 5/16 inch between each cap and a one inch border. Once you are satisfied with the spacing and placement, transfer the spacing to the front and back of the box and to a piece of thin scrap lumber. When you're placing the bottle caps, align the thin board with the index marks on the form to help keep your caps aligned.

Pour Concrete
Jeff Farris

Pour Concrete

Place 2 1/2 gallons of the concrete mix in a large bucket. Add a little less than a 1/2 gallon of clean water. The concrete should be just wet enough to flow. If it still appears crumbly after thoroughly mixing, add a little more water. If it appears runny, add more concrete mix. The correct mix appears somewhat liquid, but will hold in a lump rather than spreading. When the correct mix is achieved, fill the form about half full.

Finish Pour
Jeff Farris

Finish Pour

Press the wire into the concrete to reinforce the finished product. Make sure all parts of the mesh, including the ends are approximately in the middle of the slab, not pushed all the way to the bottom, or allowed to migrate up to the surface. Fill the rest of the way to just below the edge of the box. Press your fingers into the concrete and wiggle them around. Repeat across the entire pour. This breaks up air bubbles. Save a bit of concrete in a sealed container for embedding the bottle caps later

Finish Surface and Embed Bottle Caps
Jeff Farris

Finish Surface and Embed Bottle Caps

Trowel the surface smooth after the concrete has had some time to begin curing. You can usually do this about 1/2 hour after pouring, but it will depend on the temperature and humidity. When the concrete trowels well, but is still workable, likely about 1 hour after pouring, fill each bottle cap with some of the reserved concrete and press firmly into the poured seat. Use the index marks on the box and the guide stick you made earlier to locate each cap.

Angled Cuts
Jeff Farris

Angled Cuts

Set a miter saw to a 3 degree bevel. Cut four 2 by 2s 27 inches measured from long point to short point. Cut two 1 by 3s with the short points on the same side (trapezoid shape) to a length of 11 inches short point to short point. Cut two 1 by 3s with the short points on the same side to a length of 12 5/8 inches.

Remaining Cuts and Pocket Hole Drilling
Jeff Farris

Remaining Cuts and Pocket Hole Drilling

Return your miter saw to 90 degrees and cut 4 1 by 3s to a length of 11 inches. Drill two pocket holes in both ends of all eight 1 by 3s.

Angled Leg Assemblies
Jeff Farris

Angled Leg Assemblies

Lay out two legs and two angled stretchers as shown in Slide 7. Place a 1/4 inch piece of scrap wood under the top stretcher. Align the top edge flush with the top of the leg and screw together. Repeat on the other side. Align the lower stretcher so that the distance from the bottom to the end of the leg is the same on both sides and screw together. Repeat with the other set of legs and angled stretchers.

Square Stretchers
Jeff Farris

Square Stretchers

Join the two angled assemblies together with the square cut stretchers. Use the same 1/4 inch thick spacer and align the stretchers flush with the top and even with each other. Plug all pocket holes.

Prep and Finish
Jeff Farris

Prep and Finish

Sand all pocket hole plugs flush with stretcher surfaces. Sand stretchers and legs, starting with 80 grit, then 120 grit. 120 grit is sufficient for paint. If you choose to varnish your legs, sand with progressively finer grit paper. For a dip dyed look as shown in Slide 1, paint the legs one color from the top to the bottom of the lower stretcher.

Lower Leg Finish
Jeff Farris

Lower Leg Finish

You can actually dip the lower legs in paint, or, as shown here, you can achieve the same look by masking the leg and painting. It takes a bit more time, but uses less paint and is less messy.

Finish Seat
Jeff Farris

Finish Seat

Allow the seat to cure for two days (or a few more), then seal the concrete. Normal concrete sealers are usually only found in gallons, which is far more than is needed for this project. Normal polyurethane varnish (for wood) works just as well and can be found in half pints.

Join the Legs to the Seat
Jeff Farris

Join the Legs to the Seat

Set the seat upside down on your workbench. Center the legs on the seat and place an "L" bracket at the approximate center of each stretcher. Mark the position of the hole in the bracket onto the concrete. Drill just to the depth of your concrete screws with a masonry bit. Secure the "L" brackets to the seat with concrete screws and to the stretchers with wood screws.

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