A Creative Bowl with a Difference…:
Andy Coates creates a decorative bowl, which remains attached to its base.
Andy Coates creates a decorative bowl, which remains attached to its base
A while ago I turned a bowl on the end of a 1000 x 200 x 200mm block of oak (Quercus robur). Surprisingly it sold as a ‘floor bowl’ and I’ve always meant to make another. Recently, I found a large block of very old oak in the wood store and decided to make another, but this time I would pyrograph and colour the bowl. I like the ‘over-sized’ nature of the object and this allows for the inevitable occurrence of somebody trying to lift the bowl off the block and the incredulous look that passes over their face as they realise it is all one single piece.
I tend to use material that is not ideal for more refined projects or jobs; old posts are ideal but any large block will do. If your stock is a little rough, all the better as this provides a contrast between the turned bowl and its base. I will create further contrast by pyrographing and patinating the bowl. The intention is for an object that looks as if the block has revealed the hidden bowl, like an artefact recovered from a marine concretion.
Plans and equipment
Tools
• 10mm long-ground bowl gouge
• 10mm spindle gouge
• 10mm parting and beading tool
• 2mm parting tool
• Skew chisel
• Multi-head half-round bar scraper
Materials
• Old oak post section: 150 x 150 x 200mm
• Strip of Formica
• Abrasives 180–400 grits
• Cellulose sealer
• Patinating paint
• PPE: facemask, gloves, dust mask/respirator
1. Before you begin work examine your chosen block for any features you might wish to retain, and more importantly, any faults which may cause problems later on. Old wood can be wonderful to turn, but can also hold surprises. I decided that if possible, I would like to retain the burr section in the base
2. There were some cracks on one end face so I chose this as the end to turn the tenon on. The shape was irregular, so the centres were set by scribing the largest possible circle on each end and using the compass marks as the centre
3. First clean up the base at the tailstock end. A long ground bowl gouge was used here to ensure a clean surface cut. With an irregular blank lathe the speed was set at 900rpm for safety
4. With a square base it is vital that the surface is completely flat along the edges. If not, there will be a gap when the piece is placed on a flat surface and it may rock on the base. Use a steel edge to check and work until flat
5. As you work to create the flat area on the outside of the pencilled line you can cut the tenon at the same time. Due to the weight of the blank, mount in large gripper jaws on a 90mm tenon, remount on the tenon with tailstock support when finished
6. The next step is to create a cylindrical ‘blank’ for the bowl section. Make the cylinder as large as possible and depending on your block size, make the cylinder a third to one half of the length. Use a long-ground bowl gouge and be aware of the corners spinning by your left hand
“With a square base it is vital that the surface is completely flat along the edges”
7. Once the cylinder is roughed out, true up the face using the bowl gouge, ensuring the first 20mm is of finished standard, then move on to clean up the side face. Do not worry about the top of the base section as we will come back to that later
8. Begin shaping the bowl section using the long-ground bowl gouge. Set the initial curve at the lip and continue to work down to the same curve, but do not begin each cut at the lip or you will lose overall diameter
9. As you form the exterior of the bowl keep in mind that the foot/bowl ratio is around 40/60%. Allowance for this is your shaping. Turn the exterior bowl until it is approximately 2/3 completed and leave the remainder as support for the hollowing
10. Still using the long-ground gouge, begin hollowing the bowl. Working in steps from the centre and aim for fluid, continuous cuts from the front face to the centre of the base of the bowl. This will help to develop your bowl technique and result in better flowing curves
11. Continue hollowing the bowl with the gouge. The bevel should be rubbing to support the cutting edge and the flute direction should be at the two o’clock position. As the cut runs deeper and the curve begins to return towards the centre, be careful not to rotate the tool inwards or you risk a catch on the left wing
12. As your cuts approach the rim of the bowl decide on the finished wall thickness. If your block is reclaimed, or has faults, a thicker wall is wise to avoid turning stresses breaking the bowl and potentially posing a danger; 8–10mm is fine
13. Once you have completed the interior bowl you may need to use a scraper to refine the surface. Remember that this is not a shaping process, but a refining process. With the scraper at about 45° run the edge over any high spots beginning at the base and working outwards to the rim until the surface is uniform
14. Next return to the front of the workpiece. Begin to reduce the foot area using the bowl gouge and remember those spinning corners! Reduce the diameter of the base of the foot as you go and keep the top surface of the base section flat
15. Begin to form a clean sweeping cove between the lip of the foot and the base of the bowl. Aesthetically a step between foot and bowl works well. At the lip of the bottom of the foot form a narrow (5–7mm) edge
16. Using a large skew chisel on its side, use the long point to define and clean the edge at the base of the foot, and at the step between the foot and the bowl. Take care making these cuts; the restricted space and spinning corners make it a tricky job
Painting
Paint finishes are available in a range of colours, textures and effects. While not all are labelled as suitable for wood, many are. Experiment with a sample. Patinating finishes offer an exciting range of design opportunities
17. Make a series of decorative ‘V’-cuts on the foot and top of the bowl, but use the corner of a 10mm parting and beading tool if you prefer. These lines can be scorched in using the sharp edge of a piece of Formica. Press in firmly until the black line appears. Return to the upper surface of the base. Use a straight edge to check if the surface is flat. Do not be tempted to use a scraper as a catch on the corners is likely
18. Using the bowl gouge, cut the surface flat right up to the lip of the foot. With the flute of the gouge pointed towards the rear of the lathe, use the bevel to direct the cut along the flat plane. Slow down as you approach the foot and be careful not to catch the edge
19. The bowl can be abraded. The top base surface is best done by hand or power arbor with the lathe switched off. Remount the piece between jam plate and tailstock and at low speed carefully turn the tenon away
20. The circled pencilled on the surface will help ensure you do not create a hollow on the straight edge. Anything inside the circle can be concave as it will not alter the edge. Work down to a stub 15–20mm diameter and cut the remainder with a pull saw and the lathe switched off. Clean up with abrasive
21. Give the base section a thorough coat of Danish oil, allowing it to penetrate before wiping excess away. Several coats would be an advantage. Avoid getting oil on the bowl as this will present problems for the colour treatment
22. The next stage is to pyrograph. You want a deep burn to create texture. When pyrographing for any prolonged period ensure that the wood smoke is vented/filtered away. Work in shorts blocks of no more than 15 minutes and take rest breaks
23. Once the pyrography is complete, take a piece of nylon pad or a bronze brush and lightly brush the loose carbon away. Ensure the surface is dust free before colouring
24. How you colour the piece, and with what can be quite personal. Here I have used a proprietary brand of verdigris finish. A similar look could be achieved using a jade acrylic and a green patinating wax. Whichever you use, be careful not to get any on the base section, although the oil will help repel splashes
Pyrography
A smoke extractor is essential if doing a lot of pyrography. Place a small fan behind your work area to help drive the smoke towards the extractor. If you feel any heat through the pyrography tool stop work immediately and allow the handset to cool.
