Tuesday 27 April 2010
Michael O'Donnell talks about the design of turned vessels and how body curves and shape can be incorporated
Do you ever sit looking at a bowl blank wondering what shape to make the piece? And does the wood ever talk to you and tell you exactly what it wants to be, and then all you have to do is get on and turn it? If it does, that's quite amazing.
I have never had any experiences like that myself, not only that, the more I look at a piece of wood the more confused I get. In fact, I have had some pieces of wood for over 20 years and I still don't know what I am going to make from them. I tend to work the other way round: I consider what I want to make, have an idea of the size and the properties of the wood that would match, and then find the wood to suit.
But then, as I have limited myself to using only local wood, I can't ignore the range of woods I have available to me when I am planning what to make. Often it is having limitations like this which helps to focus the mind when looking for inspiration.
Whichever way you work, the piece needs to be designed before the first cut is made. This doesn't mean starting from a blank piece of paper, as we all have a lifetime of experience to draw on. Inspiration might come from anywhere: a piece you have seen in glass, metal or ceramic, or it could come from architecture, or something of nature in the landscape. It is easy enough to by-pass these things every day as we go about our business, the trick is to keep an eye open, train your eyes to recognise shapes, and take on-board anything that you find interesting and that you can potentially incorporate into your turnings. Take a photograph, or at least store the information in your brain for future reference purposes.
The real task is bringing that inspiration to life in your piece of wood, a little understanding of the shapes and what makes them work in a particular way is all part of the process. For example, have a look at Figs. 1a and 1b, which are similar forms - what do you think? To my eye curve 'a' is an aesthetically pleasing and flowing curve, with a constant gradually changing radius all the way round - very elliptical - and it could even be a natural form. If you handle this shape then you would feel the continuous flow of the surface under your fingers. On the other hand, shape 'b' is very regimented, made up of four distinct curves - a semicircle at either side joined by two straight lines - more built than evolved. You might think that this surface also flows around the shape, yes, it would feel nice if it curved over each of the individual sections, but there are very sudden changes in the curves at the points of intersection, from the constant small radius of the end curves to the infinite radius of the straight line; these sudden changes are jars to the surface flow. The difference between the shapes is that 'a' has constantly changing radii, while 'b' has four fixed radii with intersections. It's not to say that one of these is either good or bad, they are just different, and it is a matter of recognising the differences and how they can be used and be incorporated into your designs. And recognise the differences both visual and by touch, it is shapes that flow, without intersections, that I often look for, and a perfect example is a circle or sphere - it has a fixed radius - and there are no intersections, so it has a smooth flow all the way round. It's easy to draw and easy to recognise and you can hardly go wrong with a spherical shape.
Playing with shapes
If you have a specific idea, e.g. a large salad bowl, or a hollow vessel, then you have a starting point from which to work. If you haven't and don't have any particular inspiration, or if the wood isn't speaking to you and you think you can't draw, then you are in need of another approach. A simple, and productive way, to start exploring simple shapes for turning is to take a soft pencil and a sheet of paper, then very quickly, and in one swift movement, draw a large number '6' filling almost half an A4 page. The shape you have drawn is very likely to be a continuously changing curve, exactly what we are looking for and there is a bowl or vessel in there somewhere - probably even more than one. To find it, study the shape, turning the paper round in you hand. If you see something interesting, mark a point on the curve, which will be the centre of the form. If not, just put a random point on the curve and see what happens. Draw a line at a tangent to it, and add a dotted line at 90 degrees to represent the centre line. Put another mark in the line to represent the edge of the rim and draw a line through that parallel to the bottom line. What you have is a profile of half of the bowl. To bring it out more vividly, add on a couple of lines to represent the rim, a little shading to the edge, and there is the form.
While we have just been drawing half of the bowl, to get a picture of the full bowl fold the paper along the dotted line and cut out the shape. You can repeat the process with longer or more squat sixes or try a letter 'S' to get a variety of shapes. What you will end up with are flowing shapes, which are pleasing to the eye and can be turned into bowls. In doing this you will be training your eye to recognise nice flowing curves, so that when it comes to the turning you know what you are looking for.
After a while it will become second nature and you will no longer need this random inspiration.
With these shapes the curve flows continuously from one rim, around the bottom to the opposite rim, resulting in a round bottom. To make the shape stable, either add a foot or make the bottom flat. Whichever you chose, the curve should not change; it should still flow visually from the rim, through the foot - or through the surface it is sitting on - to the opposite rim. Yes, one curve from rim to rim, a curve that the eye can follow around the bowl, very much like what you expect of the inner shape - a curve from rim to rim. Again, you can play with sketches to see the affect of adding a base to your turnings.
Going from paper to wood is a big step as there are no 'instant' methods of producing flowing curves on the lathe. Even recognising the difference between a good shape and a poor one, particularly when the difference is small, the wood is on the lathe where your form is evolving and it's not even the right way up, can be difficult. And a dominant grain in the wood doesn't help matters either. It takes a little practise with the eye analysing forms and shapes, though there is help at hand. It might seem surprising, but the fingertips can be very sensitive to changes to the flow of a shape, sliding the fingers over the form backwards and forwards - even closing the eyes - seems to increase the sensitivity. The chances of getting the shape spot on with the gouge can be quite remote, so the surface often needs refining from here. The ideal tools for the refining stages are those such as scrapers, large scrapers, and large skewed scrapers, which are the easiest to control around large convex curves on your turnings
Once you have found a discontinuity, refine the shape with very light cuts. It might be only a few shavings, but the difference in the flow of the form can be dramatic. You might think that these differences are unimportant, but they are the points that your potential customers and clients may pick up on easily and it may mean the loss of a sale.
When looking for inspiration, keep your eyes open to the world around you and be open to influence from different sources. When you see an interesting shape, take a closer look to see how it is made up and take this on-board. Take photographs and make sketches, so that when the wood is revolving on the lathe, you know exactly what shape you are looking for. And don't forget to use your fingers to feel the shape and refine the shape until it flows all the way round.