General contractor and experienced woodturner Tom Silva loves carving and shaping wood into objects. But, when he told host Kevin O’Connor that he was planning to turn a square bowl, Kevin couldn’t believe it. With the right materials and a steady hand, it’s possible, and Tom shows Kevin how it’s done.
How to Carve a Square Bowl
- Start by ensuring that the block of wood you’re using is square. Measure it from side to side to ensure it’s equal on all sides. If it’s not, remove the required material on a miter saw.
- Use a framing square or straight edge to find the middle of the block. Mark the center and drill a hole that matches the diameter of the worm screw attachment.
- Secure the wood worm screw attachment into the lathe’s chock. Turn the lathe on and set it to a very low speed. Carefully attach the block to the worm screw.
- Working on the bottom of the bowl first, slide the lathe bench into place and use a flattening chisel to flatten the bottom of the block. Work slowly and deliberately, taking off small bits at a time.
- Once the bottom is flat, use the gouging chisel to shape the underside of the bowl. Work from the center outward, but be careful not to get hit by the legs that will slowly start to form.
- Carefully carve a round mortise into the bottom of the bowl so it can be attached to the chock.
- Sand the underside of the bowl to smooth any rough grain before applying a thin layer of food-safe oil and wax to the underside and sides of the bowl with a lint-free rag.
- Remove the bowl from the lathe, remove the worm screw, attach the bottom of the bowl to the chock, and tighten the bowl in place.
- Carve the inside of the bowl with a gouging chisel, working slowly to avoid carving all of the way through.
- Sand the inside of the bowl and apply a coat of sanding paste inside before applying a coat of food-safe oil and wax with a lint-free rag.
Pro Tip: Tom Silva, general contractor on This Old House, chose bubinga over African mahogany for his square bowl project, noting: “It’s pretty wood. It’s exotic”—and it “turns nice too.” When selecting wood for a square bowl, look for dense, exotic hardwoods that hold detail well and reveal beautiful color once oil and wax are applied.
Resources
Tom and Kevin turn a square bowl with legs out of Bubinga wood.
Be sure to sharpen lathe tools when necessary, using a sharpening machine. When turning on a lathe machine, wear a face shield and ear protection.
Tom is using Bubinga wood which is an African hardwood species.
Start by squaring up the block of wood on the table saw. Find the center of the wood and use a hand drill to make a hole to mount to the woodworm screw on the chuck.
Once the block of wood is mounted start by forming the bottom and legs of the bowl using a bowl gouge and scraper. Create a recessed notch in order to connect the bottom of the bowl to the chuck on the lathe machine.
Hand sand the bottom of the bowl using a 150-220 grit sandpaper. Once the bowl is smooth and wiped clean of dust, apply a layer of food safe finishing oil before turning the bowl over on the chuck.
After flipping the bowl on the lathe machine, use the bowl gouge to carve out the inside of the bowl. Once the inside of the bowl depth is established, use a scraper to smooth the notches out for a smooth finish. Use a hand detail sander to finely smooth the bowl before applying finishing oil to the inside of the bowl.
Creating the Tenon: Before flipping the bowl to hollow out the inside, use a parting tool to create a tenon on the bottom. This tenon allows you to use a different chuck attachment to securely hold the bowl when it’s time to turn it around. Finish sanding the outside of the bowl and apply the finishing oil before flipping—as Tom demonstrated, working through 100, 150, and 240 grit paper while the piece is still spinning makes the sanding quick and even.
Materials
Pro Tip: It’s much easier to keep the bowl mounted and turning on the lathe while you sand it. Progress through multiple grits—starting at 80, moving to 120, and finishing with 240—to remove all gouge marks and achieve a smooth surface before applying your finish.
