Turned, Steamed and Bent: vessel form
Words: Neil Turner
Photos: Suellen Turner
I was introduced to the concept of steambending during my Diploma of Arts (Fine Furniture) at the School of Wood in Dwellingup in West Australia. The notion of manipulating wood into different forms seemed appealing. Essentially, the process is about melting the glue (lignin) that holds the wood fibres together so we can re-align them.
Often when carving turned hollow forms I wondered if I could transform them using steam rather than carving them. The opportunity to explore this idea came when I attended the International Turning Exchange (ITE) in Philadelphia in 2014.
There are a couple of considerations to be mindful of when attempting to steambend round objects. For a start, you’re trying to manipulate a compound curve which is extremely rigid, however potential areas of short grain may lead to breakages. For this reason an even wall thickness is paramount so the wood will steam evenly.
To make the bending process easier it’s better to use timber that is not completely dry, with say 15–20% moisture content. This is higher than I would normally use. You can use drier timber but you may need to steam it for longer to achieve the result you’re after. The shape shown here allowed me to deconstruct the top of the form while still maintaining its overall integrity. There are other shapes that would lend themselves to similar manipulation.
Having arrived at a suitable form the next consideration was how many cuts to make. I decided to use all 24 indexing points to create as many small fingers as possible. The wider the finger of wood the more difficult it will be to bend because of the compound curve.
My inspiration for this piece was a vision of floating seaweed or kelp and combining these techniques enabled me to achieve a freeform result. The steps are described below.
1. Select a suitable piece of timber, preferably a medium density straight-grained wood. It’s important that it’s free of cracks, voids and bark inclusions. For this piece I used a piece of jacaranda.
2. Turn a spigot that’s suitable for a set of shark jaws for extra holding strength on the end that will be the base. Turn the outside shape. No need to refine at this stage, we can do that when it’s in the chuck.
3. Refine the outside shape. Drill a pilot hole to your required depth, and then hollow with your favourite hollowing tool, making sure you get an even wall thickness of 5mm throughout the whole piece. This hollowing tool I use is homemade: 3/4" mild steel shaft, the cutter is a piece of 3/16" high speed steel with an electrical tie as a depth gauge.
4. Once the hollowing is complete and while the piece is still a solid piece, it’s time to sand the inside. I use a drum sander for the sides, a flapper sander for the curve and a velcro sanding pad for the base, using an extension for all.
5. Mark the 24 indexing lines. Using a platform to rest the pencil on, I achieve accurate lines for the saw cuts.
6. Using a fine tenon saw, cut just to the bend, any further will expose the short grain to the bending process.
7. Turn a thin shaft that will fit inside the form and is long enough to be used as a drive. Using tape, place some form of friction material on the end, in this case I used some rubber matting.
8. Locate the form on the shaft using the tailstock, finish turning the form and remove the spigot. Cut off the remaining nib and finish the base. Cut 16 pieces of veneer 1mm x 20mm long and 16 pieces that are 5 x 5 x 20mm long pieces of wood, these are used to separate the fingers.
9. I didn’t use any high tech gear to make this unit. What you see are a wall paper steamer, a 20 litre steel container with a lid sporting a 8mm hole to let out the pressure, three pine legs and a fitting placed in the base to attach the steamer hose too. Just turn the unit on and get the bucket steaming.
10. Place your turned hollow vessel upside down over the hole in the bottom where the steam will be injected into the container. Leave it for 10–15 minutes depending on the type of timber used.
11. Using veneers first to initially spread the ‘fingers’, one forward, one back and so on. Reheat the form and then replace the veneers with the 5mm pieces as shown. I will repeat this process as many times as needed just pushing the small pieces of wood further down to splay the fingers more. You have to work quickly and you need to wear protective gloves as the wood is extremely hot.
When you have reached the desired distortion allow the wood to cool and then remove the wedges. The fingers will have now reached their resting position. Take care not to leave the piece in a draughty area to dry because the moisture you have added to the wood needs be removed slowly to avoid splitting.For me the fun now begins. The canvas has been made and now it’s time to go to work and shape the fingers.
12. Here I’m using a spiral cutter carve the fingers, using my thumb as a support.
13. The finer carving is completed with a 2.5mm CCF cutter.
14. The base of the segments was smoothed with a flapper sander and then refined with a rat-tail rasp wrapped in velcro sanding grit.
15. The final shaping and sanding was carried out with a 25mm sanding disc, which is a transformed silicon rubber carbide polisher with velcro attached to the bottom. I normally sand to 400 grit. The radiating pattern on the base was handcarved with a small V-tool. You can use either oil or lacquer to seal and polish the wood. Once again, my inspiration for this piece was a vision of floating seaweed or kelp.
Neil Turner is a wood artist who lives in Stratham, WA. Contact him via www.neilturnerartisan.com.au