Coffee Stirrer Bowl
Thursday 30 September 2010
Bob Chapman shares this quirky project with us which sees him creating a bowl made from discarded, signed coffee stirrers from the AWGB Seminar
The idea for this bowl came when I was demonstrating at the AWGB Seminar at Loughborough University last August. The evening before the seminar began, the members of the organising committee and the presenters had just finished a meal together and the table was strewn with these slim wooden sticks. In a moment of madness, instantly regretted, I suggested that if enough used stirrers could be collected during the seminar, I would convert them into a bowl.
The other presenters immediately wanted to know how I could make a bowl out of these sticks, and in truth I hadn't actually got a clue. "Oh, I'll figure out a way," I said airily, as if I did this sort of thing all the time. Not intending to let me off the hook for want of material, Mike Donovan, an AWGB committee member, took up the challenge with relish and over the next three days organised the collection of what turned out to be 568 coffee stirrers. "What a very nice, helpful man" said my wife, Linda.
I couldn't believe I'd actually said it out loud: I'd offered to turn a bowl out of wooden coffee stirrers and I'd used my outside voice when I thought I was using my inside voice.
Tools used: 3mm (1/8in) parting tool and 13mm (1/2in) bowl gouge
For hygiene purposes, put the stirrers in a bucket full of bleach for a couple of hours, then rinse in clean water before allowing them to dry. To form a bowl the stirrers obviously need to be bent to shape. Turn a former from a piece of sycamore (Acer pseudoplatanus) and cut a groove near the top to hold the sticks in place without glue
Bend the sticks round the former and use a cone tailstock centre to hold the inner ends in place. Then, glue a second layer of stirrers to the first layer using Cyanoacrylate. Put small drops of glue on the stirrers of the first layer and spray the stirrers to be added with accelerator before pressing them in place
Add further stirrers, gluing each one to those underneath. Take care not to glue any of them to the sycamore former
Cut and add more coffee stirrers and place them on the outer surface. The gaps will gradually be filled in and it will begin to look more like a bowl exterior. Be aware that the surface may become very uneven and it may get more and more difficult to bend and glue more stirrers securely to the surface
To level the surface skim the exterior of the bowl with a 13mm (1/2in) bowl gouge, taking a very light shearing cut with the gouge's lower wing held at approximately 45 degrees. The wood of the stirrers will cut very easily and will leave a surprisingly good surface over most of the bowl
Unfortunately, on my attempt, the sticks were only about 1.5m (1/16in) thick and where they stood proud they were completely removed by the gouge, leaving a number of ragged holes in an otherwise level surface. Also, I was far from happy with the appearance where I had cut the stirrers at angles to try to improve the way they fitted together. Cutting off the rounded ends of the sticks had somehow obliterated their identity as coffee stirrers, and the whole point of making the bowl was in danger of being lost. To tidy up the surface another layer of sticks was glued onto the levelled surface, but this time the rounded ends were retained. The bowl was divided into eight sections and the stirrers were glued at an angle over the bowl, forming a sort of 'half-herringbone' pattern
Leave the rounded ends on the coffee stirrers as these create quite large voids where the round ends meet a straight side. Fill these with a stiff paste made by mixing fine wood dust with Fastglas polyester resin. The dust is very fine and floury, and sticks to the outside of the paper filter inside dust extractors. Mix the dust with the resin to the desired consistency before adding the hardener
And the hardener to the mixture and cover the surface of the bowl. Make sure the filler is pressed firmly into the cracks between the stirrers and that any other gaps are filled slightly proud of the surface. The filler sets quite quickly but I recommend leaving it overnight
The resin will set hard but cuts fairly easily with an HSS gouge. Again, skim the exterior to give a smooth and level surface
After skimming it became obvious that there were some low spots in the surface which retained a coating of the filler. I decided not to try to take more off the surface for fear of going through the stirrers at their highest points, and so...
...yet another layer of stirrers was added. Note: these are laid across those below, giving strength to the construction. As they were being laid on a 'true' surface, this layer of sticks should also be true, allowing them to be the final layer
When the stirrers are glued down the ends may overlap the top of the bowl, so these can be cut off with scissors. The top edge will be cleaned up later
Fill the surface again, but this time add a couple of spoonfuls of old toner from a laser printer. This will be enough to make the filler black rather than the brownish-red colour obtained by using wood dust only
After a final skim with the bowl gouge sand the surface lightly from 120 grit down to 400 grit, then seal and polish. Use a mixture of beeswax and Carnauba wax, but there is no reason why you shouldn't use your own choice of wax, or oil finish, as desired
Use a second piece of sycamore as a former for the foot of the bowl. I always think that if the diameter of the foot is about one-third the diameter of the bowl it will look right, so I turned a sycamore former of the correct diameter first. Bend the coffee stirrers around this and glue to it, making sure that each layer overlaps the joints in the layer below. Four layers are sufficient. Fill any gaps as before and clean up the foot before parting through the sycamore to release it from the former
Using a 3mm (1/8in) parting tool cut a groove in the bottom of the bowl to take the foot as a close fit. Then, glue in place with Cyanoacrylate, using a piece of scrap plywood and pressure from the tailstock to keep it level while the glue sets. After polishing the foot, the outside of the bowl is complete
To work on the inside of the bowl hold it in a vacuum chuck. However, one of the difficulties of using a vacuum chuck is centring the workpiece, and in this case it will take around five minutes of trial and error, and making small adjustments
I had hoped to simply pull the sycamore former out of the bowl, leaving the stirrer assembly intact, but it was not to be. Somewhere along the line the Cyanoacrylate must have dribbled down and glued the stirrers to the former. Annoyingly, there seemed no way to remove it in one piece, so it had to be turned away. It was carefully cut back with a bowl gouge to reveal the stirrers on the inside
As it happened, once I'd turned the former away to about half its diameter, it came loose and was removed without further turning, revealing the untidy arrangement of coffee stirrers that I'd started with. It occurred to me at this point that if I'd simply glued the stirrers to the former to begin with, I could have done a much neater job and would have been no worse off because I'd had to destroy the former anyway. A wonderful thing, hindsight
To have any hope of tidying up the inner surface it would have to be levelled and smoothed with filler. Make a coarse filler, as before, but simply use the coarse dust from the bandsaw, worked in with your fingers
Use the cone centre in the tailstock to hold the piece securely on the chuck while turning the pump off and leaving everything to set. Leave overnight, then the next morning turn the pump on and remove the tailstock once the vacuum has gripped the bowl again
It took two further layers of stirrers to get a good finish on the bowl interior