loading

A concrete form tube is almost all you need to make this side stool. The finished piece is hollow and weighs about 20-25 lbs. depending on the thickness.

Materials and Supplies:

  • Rubber Gloves, Safety Glasses, Dust Mask
  • 10" Concrete Form Tube
  • Shelf Liner
  • Spray Adhesive
  • 11"x11" Plastic Sheet
  • Base Surface
  • Duct Tape
  • Mixing Containers
  • 25 lbs. ShapeCrete

Tools:

  • Hand Saw
  • Utility Knife
  • Ruler / Square
  • Hot Glue Gun
  • 100% Silicone Caulk and Caulking Gun
  • CHENG Corner and Seam Shaping Tool
  • Razor Blade
  • Trowel
  • Diamond Hand Sanding Pad

Step 1: Cut Down Concrete Form Tube

    • Measure down the form tube and make marks with a pen at 18".
    • Tape around the tube to connect the marks. The tape will act as a guide, making it easier to cut the tube straight.
    • Cut the tube to size with a hand saw, utility knife, or band saw.

    Step 2: Glue Shelf Liner in Place

    This is the trickiest part of the project, but it's optional. Gluing a plastic shelf liner inside the tube will give the finished piece a texture. The shelf liner here is just over 18" in width, so it fits perfectly inside the 18" tall form tube.

    • Tape the shelf liner in place, working your way around the inside of the tube and making sure that the liner is tight against the inside.
    • Make a mark on the liner where it meets the starting point.
    • Cut the liner to length with a utility knife, using a ruler as a guide.
    • Lay down some contact paper and spray the non-textured side of the shelf liner with spray adhesive. Follow the directions on the adhesive and spray the interior of the tube, then wait 5-10 minutes for the adhesive to get tacky.
    • Carefully place the liner inside the tube and press it into place.
    • Trim away excess with a utility knife.

    Step 3: Make the Base and Glue Down the Tube

    Make the base for the form tube using something flat, like a scrap piece of plywood, or in this case, a terracotta tile that was laying around. Tape a piece of plastic (11"x11") to the tile. The plastic will make it easy to remove from the piece later.

    • Tape the plastic down on the tile.
    • Place the form tube in the center of the tile.
    • Run a bead of hot glue around the base of the form tube to hold it in place.

    Step 4: Silicone the Inside Edge

    This step is also optional, but it will create a nice round-over on the top edge. If you skip this step, the top will have some sharp edges that need to be sanded down with diamond hand pads.

    • Run a bead of caulk around the bottom inside edge of the tube.
    • Tool the caulk with a seam shaping tool (an acrylic rod cut at an angle).
    • Scrape up the excess silicone with a razor blade.
    • Wait for the silicone to cure and then pull up the excess silicone from the sides of the tube.
    • After the silicone has fully cured, clean out the form with denatured alcohol.

    Now the form is ready to pack.

    Step 5: Mix ShapeCrete

    A project this size will take about 25 lbs. of mix, at about 5/8" - 3/4" thick. It helps to mix this amount in a 5-gallon bucket or a concrete mixing tub.

    Mix ShapeCrete to a Clay-Like Consistency.

    • Add half the water to the tub.
    • Add the dry mix with the dry pigment already blended in (optional).
    • Blend thoroughly by hand or with a paddle mixer. The mix should hang vertically when it's the right consistency. Adjust water content as needed.

    Always wear a rubber gloves, safety glasses, and a dust mask when mixing.

    Step 6: Pack the Form

    • Begin by packing the bottom of the form to an even thickness. Press the mix into the edges of the form so you don't leave air bubbles.
    • Gradually pack the mix up the walls of the form, turning it as you go along.

    • If the mix is slumping down, it may be too wet. Try pressing thinner pads into the form and then coming back with a second layer to thicken it up.

    • When you get to the top of the form, smooth the top edge with a trowel or putty knife.

    Cover with plastic and let it cure for 24-48 hours before removing it from the form.

    Step 7: Demold

    Stripping the form is easy.

    • Remove the tape from the tile so the plastic is loose.
    • Flip the piece over and peel away the plastic.
    • Use a utility knife to carefully slice into the tube and gradually peel it away. Be careful not to cut too deep into the piece.
    • Sand any jagged edges with diamond hand pads, files, or coarse sandpaper.

    Step 8: The Finished Piece

    Concrete form tubes are really versatile and come in a huge range of sizes so they can be used to make a lot of different (cylindrical) things. The tubes can be packed to form planters, waste bin surrounds, small containers, or short side tables like this project.

    Thanks for reading and following!

    <p>Do you think it will look good if I paint it over?</p>
    <p>I think it can look great if you paint it! You could also stain it for a less uniform look. </p>
    <p>This is far out!</p><p>I love all the things you do with concrete, it would be cool to see a concrete fountain!</p>
    Great instructable! How large can you build it without reinforcement?

    About This Instructable

    8,665views

    193favorites

    License:

    Bio: ShapeCrete is a just-add-water-and-use, shape-able concrete that can be poured, rolled, pushed or molded in an infinite array of custom concrete designs. ShapeCrete is rolling ... More »
    More by ShapeCrete Mix:ShapeCrete :: Hypertufa / Concrete Planters for Teance Tea Shop Concrete Hostess Station for Green Zone Restaurant Cast Concrete Chessboard 
    Add instructable to: