Natural Edge Work

Natural Edge Work:
Richard Findley tackles 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 and 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, who 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 which, he explains, 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. Armed 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 and press ‘start’, initially at 950rpm but soon moving 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, but 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.

Hollowing
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 and 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, often 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.

Turning a natural edge bowl
The log that I have selected for the bowl needs cutting round on the bandsaw. Fortunately, George has cut a flat on the base, large enough for it to sit on the table of the saw without rocking as I cut it. To guide my
saw I cut out a 200mm disc of 6mm MDF, which I loosely fix to the log with a nail through the centre of the disc. As with many of the techniques I’m using in these articles, this is something I’ve seen done many times in books and magazines but have never tried, and I’m impressed at its simplicity and how well it works.
As before, I mount this block between centres. It’s hard to see from the picture but I mounted it at quite an angle to give me a more even top profile. Had I used a faceplate, the rim would have been quite skewed and I think, far more challenging to turn. This can be quite stunning to see in a finished bowl, but as it’s my first I decide to err on the side of caution.
With the block held tightly between centres I use my 16mm diameter bowl gouge to bring it to round. I take a look at the bark once it is running true and spot a small area where the bark is coming away from the wood. Time for some CA! I’m aware that sometimes adding CA can solve one problem but add another in the form of staining the wood and bark, so I give the area a liberal coat of sanding sealer first. Once dry I run some thin superglue into the offending area and apply a little pressure until it holds. It seems to do the trick and suggests to me that spotting a problem with the bark early is going to be the best way to head off problems.
Happy with my work so far, I cut a holding spigot on the base and mount it in the chuck. From here I can begin to shape the bowl. Initially I work with the grain, from base to rim to get the rough shape I want, but remembering George’s advice to work from bark into the bowl I change direction and take a light push cut from the bark towards the base with my 12mm diameter bowl gouge. Out of curiosity I stop the lathe and take a look at the finish. In kiln dried timber this would probably be torn and coarse but in this wet hawthorn the surface is as smooth as silk, especially compared to the aggressive roughing cut I had previously made. I continue shaping the outside of the bowl until I’m happy with the curve and refine it with a light shear cut using the  wing of the bowl gouge.

Hollowing the bowl
The outside didn’t pose any real problems but I feel like hollowing into the bowl is going to be the real test. I begin cutting well in from the rim, as I had with the outside of the vessel earlier, and gradually work back towards the edge. I stop and check the bark and the cleanliness of the cut a few times along the way, particularly the area I have already glued but all seems fine. As I continue my confidence grows, but I still stop the lathe and check the quality of the bark a number of times. Sure enough, I spot another area that seems to be lifting a little from the wood, so I repeat the process of liberally spraying with sanding sealer and, once dry, run plenty of thin CA into the offending area and hold it tight to the wood for a short while until the glue does it’s job. Once I’m happy it’s dry, I carry on turning, continuing to check the bark and the wall thickness as I go. I settle on a wall thickness of 6mm, which I feel looks right and gives the bark the best chance of staying put.
I have read a lot about problems associated with CA glue staining the wood and bark where it has been repaired. Admittedly, I only have this experience to draw upon, but it seems to me that constant monitoring
of the bark to head off problems before they happen is the key to avoiding this problem. The use of sanding sealer is often quoted as a solution to the staining issue, which is my main reason for using it, but I suspect much of my success with this relates to the fact I then cut the surface again after the glue had dried, removing any staining in the process. I asked George if the bark is likely to come away as they dry, but in his experience, if the bark can stay on during the stresses of turning, it is unlikely to come off later.

Turning the bowl
While this is not a bowl turning article per se, there are a couple of points I feel are worth mentioning about turning a bowl of this depth and thickness. You will notice that I don’t hollow the bowl in the traditional manner, by removing the centre and gradually working out to a finishing cut all the way along the inside of the bowl. A green wood bowl will have moved considerably by the time I get to this stage and it would be virtually impossible to finish to an even wall thickness without serious vibration and movement issues. Instead I choose to work down the outer edge, focusing on a small area at a time, getting it cut cleanly and to thickness, before moving on to the next section. I only remove the central core as I find it gets in my way. I find this method works so much better, offering support to the bowl for longer and giving me a better chance of achieving an even wall thickness throughout.
The second point that is worth a mention is turning the very bottom of a relatively deep but narrow bowl. My usual grind angle for a bowl gouge is around 60º, which I find incredibly versatile for bowl turning in most situations, but here I find that I can’t maintain bevel contact along the very bottom of the bowl due to the rim restricting my presentation angle. To get around this I briefly visit the grinder and touch the nose of the gouge to the wheel at a much steeper angle than usual, allowing easy access to the bottom of the bowl. 

Finishing the bowl
Happy with the inside of the bowl and the wall thickness, I just need to sand and finish the base of the bowl. Sanding is reasonably straightforward, although I find the wet wood does clog the abrasive, which means I use more than I usually would, but with a combination of power and hand sanding, both with the lathe running and stationary, I get the bowl sanded to my satisfaction, from 120 to 400 grit.
When I remove the bowl from the chuck it is clear that, as I expected, there would be plenty more wood to remove to achieve the curve I want. Usually I remount my bowls between a disc of MDF fixed to a faceplate and my live centre. This, however, relies on the flat rim of the bowl sitting against the MDF which I obviously can’t do here, so instead I neatly fold a load of paper towel into a square to pad out the inside of the bowl against the face of the chuck. Not entirely convinced it will be enough padding, I also cut a piece of bubble wrap which I fold up and place inside the paper towel for even more padding. I then bring up the tailstock and engage the live centre as usual. This allows me good access to the base of the bowl to turn a small foot and perfect the lower curve of the bowl and I find that, when I remove the bowl from the chuck, there is are no marks on it, making it a success!
As I had done with the end grain vessel, I power sanded the base of the foot to the same standard as the rest of the bowl. Both items were then coated with a liberal coat of thinned down hard wax oil to protect them while they spend a few weeks fully drying out. The oil also immediately darkened the bark, making a stark contrast between the creamy wood and dark outer layer.

Conclusion
I am very pleased with how these have both turned out. Natural edge work has always been something of a mystery, but it actually isn’t as difficult as it perhaps appears.
As with every turning project, timber selection is key, but so are sharp tools (as ever) along with good presentation and good tool control. This has been an interesting and fun challenge which has given me two very nice pieces of work. They will be finished in a few weeks with multiple coats of hard wax oil. The finished vessel is 110mm diameter and 100mm tall, the bowl is 180mm diameter and 120mm tall.