Sculptural Wide Rim Bowl
Thursday 18 November 2010
Mark Sanger takes influence from an old millstone and creates a sculptural wide rim bowl from a piece of beech
The reference source for my work is generally eclectic. I can come up with an idea from watching television, reading a book or just seeing something while out and about. While I was looking at old millstones on the Internet, I started to come up with the idea of taking an item from my repertoire and adapting it to produce a sculptural form. The wide rim bowl with textured and scorched rim is probably as old as the hills, but by standing it upright on a plinth and adding a painted sphere it can open up a whole new area of exploration. The bowl now becomes totally sculptural without the restriction of having a use, and can be adapted and altered with the only restriction being that of my own creative ideas.
The millstone I had seen was leant up against the wall of an old house. Its textured surface was interesting and I thought it would be fun to take different elements of my work and make a sculpture in the round. As you can see, I strayed a long way from that of a traditional millstone, but often just seeing a shape or something new can trigger a whole new idea.
For the project I used a 300mm (11 1/2in) diameter x 50mm (2in) beech (Fagus sylvatica) bowl blank. Beech is a good wood to use as it takes texturing well and gives a good contrast when scorched. Alternatively any close grained light coloured wood could be used.
To add interest and a break in the round form I decided to include a cut out from the bead up to the rim, thereby breaking the round form. Within the bowl itself a sphere was turned and sprayed with car paints.
On this sphere I wanted to add a striking splash of red colour. The red was then related back into the scorching produced around the rim of the bowl, spraying black paint over the sphere with only light pressure to the nozzle of the can - this caused the paint to spit/splutter out of the nozzle and gave the speckled effect. The form was drilled through the edge and attached to a black 120 x 90 x 60mm (4 3/4 x 3 1/2 x 2 3/8in) plinth that was sprayed black with a 12mm (1/2in) metal rod, which separated the two. I decided to use a stainless type rod, as I wanted to also add a contemporary twist and a contrast to the wood in both colour and material.
Any addition of colour, texture or other media can be included into the project, and by adding your own ideas there are many possibilities.
Tools used: 12mm (1/2in) bowl gouge, 10mm (3/8in) bowl gouge, 10mm (3/78in) spindle gouge, 12mm (1/2in) skew chisel, 6mm (1/4in) point tool, 3mm (1/8in) parting tool, 6mm (1/4in) parting tool, square-end scraper, round-nosed scraper
The first step here is to mount the beech blank onto a M10 screw chuck. Drill the hole for this around 5-10mm (3/16-3/8in) deeper than the screw. This extra depth will be needed later when drilling through the front of the project. Use a 12mm (1/2in) bowl gouge to balance the outside of the blank and clean up the front face
The next step is to use a pencil to mark the centre of the outside of the rim taking into account the need to clean up the back face of the blank. Mark a 20mm (3/4in) area straddling the centre line - this is the area where the metal rod will be inserted - and gives a guide as to how much material can be removed when profiling the two faces of the beech blank. After this stage you will need to mark the area of the bowl and bead. I made the diameter of the outside of the bead one-third the diameter of the blank
Use a point tool to denote the outside of the bead to a depth of around 3mm (1/8in). Alternatively a 12mm (1/2in) skew chisel could be used horizontally on the toolrest in the trailing mode. Use the 12mm (1/2in) bowl gouge to profile the front face, blending outwards to produce a gradual convex curve. Once this is produced use fine finishing cuts to complete. This area is going to be textured so scraping and sanding is not required
Take the project from the lathe and draw your cut out design onto the rim. Be mindful that the top and bottom of the design need to be central. Note: I have drawn a central line. Once you are happy with the design cut out using a bandsaw. The back of the project is flat so there is not any need for additional support. However, if the blank you are using is not flat, clean up the back face before removing for this process. Cut sections from the design as I have done here, that way the saw blade will be able to round any tight corners
Remount the blank and use 120 grit abrasive wrapped around a half round file to refine the profile of the cut out. Proceed down through the grits to 320 to finish
Use a Lancelot cutter and an angle grinder to produce your desired texturing on the front face. Make the grooves around 5mm (3/16in) deep so that a good definition can be achieved when scorching
Use a blowtorch to scorch the texturing. Keep the flame moving over the surface without stopping in any one place. This will scorch the high spots of the texturing and will give a contrast with the beech wood
Use a point tool to produce the bead and scorch to blend in with the textured rim
Take a 15mm (5/8in) bowl gouge and turn out the bowl section. Make sure the bowl rim is undercut and deep enough to take the Cole jaw buttons - this being the next method of workholding for the project on the lathe. Use a 25mm (1in) round-nosed scraper to refine the inside of the bowl
Use a 2mm (5/64in) drill in a Jacobs chuck to drill a central hole right through the blank and into the cavity of the hole made for the screw chuck. Be mindful not to drill into the screw of the chuck. However, as we drilled the hole deeper than required at the start, you should be able to feel when the 2mm (2/64in) hole has been drilled all the way through
Finish the inside of the bowl, using abrasive from 120-400 grit on a sanding arbor and power drill. Make sure you have the correct direct, ambient air extraction as well as a suitable facemask
Seal the textured area and the inside of the bowl with Chestnut acrylic sanding sealer. Once dry, the bowl area can be cut back with '0000' wire wool, if required, with the lathe speed around 200rpm. At this stage, I refined the right top side of the cut out as I was not happy with the profile; this was then finished as before. Once the sealer has been cut back, finish with Chestnut satin acrylic lacquer
Reverse the project and hold it using Cole Jaws. Protect the inside of the bowl using kitchen towel. Bring the tailcentre up for added security and use a 12mm (1/2in) bowl gouge to clean up and produce the profile to replicate that of the front. Blend the profile up to the line drawn at the beginning, as removing too much material will make it difficult to drill the hole for the connecting metal rod. Use a 50mm (2in) square-end scraper to refine the finish, then abrade down to 400 grit abrasive, as before. Finish the outside rim of the project by applying only light pressure to the sanding arbor. By doing this, the cut out area will not cause any problems with the intermittent contact. Seal with acrylic sanding sealer, then, once dry, cut back with wire wool. Finish with several fine coats of satin lacquer
Rough down a 120mm (4 3/4in) long piece of beech with the grain running parallel to the centre axis of the lathe, to 50mm (2in) in diameter. Produce a spigot at one end to suit the your chuck jaws. Clean up the front face, using a 6mm (1/4in) spindle gouge, and mark a distance of 50mm (2in) from the end of the blank, using a pencil and rule. Use the 6mm (1/4in) spindle gouge to produce a sphere, leaving around 20mm (3/4in) of waste wood at the chuck end
Use a drill within a Jacobs chuck to drill a hole into the front of the sphere, which needs to be around 15mm (5/8in) deep. Once this is drilled, continue to shape the profile of the sphere with the 6mm (1/4in) spindle gouge. Finish the sphere with abrasive - by hand - down to 400 grit. Part off with a 3mm (1/8in) parting tool and finish the end by hand, using a suitable abrasive
Seal the sphere with acrylic sanding sealer, then allow to dry and cut back the surface with '0000' wire wool. Spray several fine coats of spray paint - I used acrylic car paint - and allow to dry between coats. Then, apply a splatter spray of black acrylic paint by pressing the nozzle of the aerosol can lightly so that the spray splatters out of the nozzle onto the sphere. If it does go wrong, just overspray again with the red paint
Drill a 3mm (1/8in) pilot hole 25mm (1in) deep in the edge of the main form then final drill to 12mm (1/2in) diameter. If you have a dedicated boring system that will fit into the banjo of your lathe, the indexing system can be used to drill the hole. However, if you do not, you can use an elastic band and a pillar drill instead. The important aspect, other than drilling the hole vertically through the main form, is to make sure that the centre axis of the hole lines up directly through the drilled hole of the bowl, and the centre of the cut out. Use an elastic band - as shown - stretching it from the cut out to the highest arc of the outside opposite. The band can be easily moved until it lines up over the centre of the bowl. You can then screw the form through the centre bowl hole to an MDF plate attached to the drill table, using a standard wood screw. Check the vertical axis of the elastic band with a small spirit level before final tightening
Rough down a contrasting piece of timber to the round and turn a button to the diameter of the recess in the back of the main form, then slightly convex the front face, using a gouge. Sand down to 400 grit, then seal and finish with acrylic sanding sealer and lacquer. Finally, part off so that the button will fit flush into the recess
Drip medium viscosity Cyanoacrylate adhesive into the hole of the sphere and attach to the inside of the bowl by screwing a 3mm (1/8in) wood screw through the central hole from the back face. Apply a small amount of Cyanoacrylate adhesive to the recess at the back, before gluing the button in place
Produce a plinth from beech which measures 120 x 90 x 60mm (4 3/4 x 3 1/2 x 2 3/8in) high. Mark the centre of the top face and drill a hole around 30mm (1 1/8in) deep to take the metal fixing rod. Finish the plinth with abrasive down to 400 grit. Seal with acrylic lacquer, spray black and seal with acrylic satin lacquer. Use epoxy resin to glue in both the hole of the plinth and the base of the form, then assemble the parts. Make sure the form is aligned parallel to the front face of the plinth, as once the glue is dry it cannot be altered