Richard Findley tackles natural edge work.
What is natural edge work?
Natural edge work, sometimes called live edge, refers to turning where the bark or the natural profile of the outer edge of the tree is visible on the finished item. The only natural edge work I’ve ever done is turning yew (Taxus baccata) mushrooms, leaving a ring of bark around the foot and edge of the cap, but I have never tried anything bigger. As I’m sure most readers will be aware, there are two ways of mounting any piece of timber on a lathe, either in a spindle type orientation, where the grain runs with the bed bars of the lathe, or cross grain, where the grain runs across the bed bars. In both cases, natural edge vessels can be turned. The editor challenged me to make something natural edged in both orientations. Challenge set, I went to work sourcing timber and working out how I was going to make these two items and keep the bark on.
The plan
My intention is to turn a cross-grain bowl with a natural edge, and a thin end grain goblet or small vase type vessel. I will keep the designs simple and focus on clean lines, fluid curves and keeping the bark on the edges of both. The timber will be green for this, so I will once again be grumbling about wet wood, long shavings everywhere and keeping my prime seasoned timber safe from high moisture and creepy crawlies!
The theory
Turning both of these items should be basically the same as turning any bowl or end grain vessel, goblet or fancy box – just with the added complication of trying to keep the bark in place. I have been armed with a number of tips to help me to achieve this, and I believe that sharp, well presented tools, good tool control and my own experience of turning should make it reasonably straightforward… but we shall see!
Timber and tips
All of my usual sources of timber are for furniture grade seasoned timber, so I once again call around to see my friend George Watkins. He makes a lot of green hollow forms and vessels of every sort, including natural edge work. As I had with the hollow forms articles earlier in the series, I not only get the timber from him, but also bring away a host of top tips to help me to achieve my aim successfully. Having explained to him exactly what I plan to make, he is able to sort out some hawthorn (Crataegus spp.) for me. He explains that it is not only a lovely tight-grained timber to turn, but is also well attached to its bark. It seems to me, from my discussion with George, that timber selection is – as always – key to success with natural edge work.
Planning and preparation
George kindly gave me several blocks of timber, from which I select a piece of each orientation for the job. With the timber, I am able to make a loose plan of action. I am no artist, but I can make sketches which make sense – at least they do to me! I also put my moisture metre on the timber (more out of interest than anything else) and it read 33% which means, according to George, that the free water has gone from the wood. This means that I shouldn’t get drenched as I turn, but it is green enough to make turning easy and make long streamers of shavings.
George tells me he prefers to hold this type of work on a faceplate as it is the most secure option. It is the way he is used to working and suits his style of turning best. But as I look at the large faceplates for my old Wadkin lathe, I decide this is probably going to cause me more problems than it solves. So, I decide to mount them between centres initially. Once I’m happy with how they run and look, I will cut a chucking spigot on the base and continue from there. I decide that the end grain vessel is likely to be the easiest, being a smaller diameter and basically spindle turning – so I start with this. I am hoping to use it as practice for the next part of the challenge, so I stand the best chance of keeping the bark on the more technically difficult and uneven shaped bowl. Armed with some promising looking timber, a selection of sharp tools and a bottle of CA (superglue), I am ready to make a start.
Top tips for keeping bark in place
• Careful timber selection, as some timbers will keep their bark better than others. Good choices are usually from trees with relatively thin bark which include hawthorn, yew, laburnum (Laburnum anagyroides) and box (Buxus sempervirens).
• Timber with thicker bark such as oak (Quercus robur) and ash (Fraxinus excelsior) can work but can be a little more difficult.
• Use timber felled in the autumn, when there seems to be less sap in the layer between the wood and the bark.
• Turn it green, although not necessarily dripping wet – this timber is 33% moisture content.
• Turn from the bark into the vessel, even when this is technically against the grain. Turning the other way risks pulling off the bark.
• Keep thin CA (superglue) close to hand in case any bark begins to come loose
• Some timbers look great even without the bark – just by keeping the natural form of the edge of the tree, so it might not be the end of the world if you can’t keep the bark on.
Turning an end grain vessel
The first step is to decide which end would be the top and try to find the position between centres that is most evenly balanced – both in weight and visually. I mount it between my Evolution drive centre and live ring centre, carefully adjust the toolrest to make sure the log spins freely. Initially I spin it at 950rpm, but soon move up to 1450rpm. I take a few passes across the end grain of the top of my vessel with my spindle gouge to clean it off and take my first look at the timber. It is creamy white and cuts beautifully straight from the gouge. The bark also appears to have withstood these first cuts well. I’m hopeful I won’t have to break out the superglue at all today!
At the other end of the log, which is around 110mm diameter and about 180mm long, I cut a chucking spigot with my beading and parting tool and Vernier callipers, allowing me to mount it straight into my chuck. With the tailstock still in place for some additional support, I begin to form the curve of the cup part of the vessel. My initial cuts are well away from the edge, and I work gradually towards it, often checking the state of the bark to see if it shows any sign of coming away. I’m encouraged to see that everything looks good. I use my 12mm spindle gouge to develop the curve of the cup. I don’t want to take it all the way to finished size in case it’s too thin to withstand the hollowing, but need most of the shape to guide the hollowing stage. So I switch to my roughing gouge to take the rest of the log down to round, and then further refine the cup with the spindle gouge until I am comfortable to move to the hollowing stage. I am aware that there will be more work to do on the outside a little later.
Hallowing
With the tailstock removed I can begin hollowing the cup. I use the smaller 10mm spindle gouge here in the hope that I will be applying less pressure to the wood and reduce the risk of damaging the bark. The hawthorn cuts beautifully, even though I’m technically cutting against the grain. I imagine this is partly due to the close grained nature of the timber and partly due to the moisture content. Either way it makes turning easy. I take it to the point where the small gouge can no longer handle the overhang. I switch to my Hope 6mm pro-carbide tool (which I bought after using one for the hollow forms article) to achieve the depth and fluid curve that I want – frequently checking the wall thickness with my callipers along the way, before sanding the inside from 120 to 400 grit.
Happy with the inside, I move back to the outside and finish off the outer curve, taking it to an even 3mm all around. I turn a bead detail below the cup and form a foot. I could have kept the foot at the full diameter and left a natural edge here too, but I feel like this would have been purely for the sake of another natural edge, rather than to make the vessel look its best. I feel that it has a better balance like this, but that’s just my opinion. I hollow the base as much as I can, aware that if I leave the base too thick it could crack as it dries, and, while it is still attached to the waste block – all be it by quite a small section – I sand the base. I use a saw to cut the vessel free and power sand the underside of the base to the same 400 grit as the rest of it. A last close look reveals the bark is perfectly attached, which gives me confidence to move straight on to the bowl.
Summary
I would say that turning this vase whilst leaving a natural edge has been a success. Key to this has been choosing the right wood with the correct moisture levels, and progressing slowly and methodically. It’s important to continually check the thickness of the bowl throughout the turning process. I would also recommend brushing up on one’s knowledge about how to dry greenwood. A well thought out process is important for ensuring that no cracks form whilst drying. In the second part of this series, I will attempt to turn a green bowl with a natural edge.