Burley & Daughter demonstrate the art of timber ebonisation, running through the three stages of the process; the preparation of the timber and the extraction of the tannins, the application of the ebonisation solution and finally, the finishing with WaxOil.
The final experiment in The London Plane Project was to create a small batch job on a CNC machine to explore the materials value in repetition and uniformity. I drew a picture of a London Plane leaf and imported it into software for the CNC machine to mass produce. I would finish these leaves by hand being careful not to alter the faces of the leaves and their uniformity maintained.
Regarding Software. I started by using Autodesk Fusion but this heavy and complicated software is more appropriate for complex, multi layered models and also the more geometric. The simple yet organic image of the leaf was more suited to another application – Vectrix, were I imported my vector directly into the application without the need to extrude or further manipulate.
Observations on it working. Some of the stock twisted over the weekend and the cutter passed through deeper at one end of the stock to the other but with planning and sanding this discrepancy was easily removed. And despite my worries, the sharpness and speed of the cutter passed over knots without exploding the stock. This was a simple job and problems only really occurred during the setting up of the machine itself and once tested the cutting out of a leaf form was never going to be a challenge from a milling point of view.
Ultimately, repetitive uniformity is what was needed and this is what has been achieved - the different figures and grain pattern has been accentuated when captured within the standardised form. A fitting finish to the London Plane Project – showcasing the variety of tones and textures from one timber.
My next experiment with London Plane was to use various parts of the living tree to stain seasoned timber. I tried different leaves off different trees but the waxy leaves didn't really break down, even after a couple of hours of patiently adding water and mordant and not letting it dry out. The bark created only a brown colourisation. I eventually elected to use the Button balls or seed containers that you find on the London Plane tree - a sort of soft conker.
I chopped the material up very fine and then added it to the boiling water and then reduced it down as much possible. I spent two hours adding water. I used Alum as a mordant as it was readily available and because its powdered I guess, I found it easy to judge the appropriate quantities needed during the process. I added the Alum while the simmering vegetation was still on the stove and so easily settled on the right consistency and colour. When I was happy I removed from the heat and let it cool down. Once room temperature I used a Muller to grind it down to a fine pulp.
When applying to the timber, I selected the palest stock I could fine and finished it to 240 grit and then prepared it with vinegar water solution. Once dry I cut back the raised timber fibres with a very fine abrasive and then applied the stain generously.
The result is not at the brilliant end of the colour scale but is certainly worth the small amount of effort producing a chalky green – not unlike French Grey.
Timber selection is always important when it comes to steam bending and selecting the right Lacewood is no exception. Is the grain straight enough but still have character? Is the timber free from knots and defects? I could not find any advice regarding the steam treatment of London Plane, quarter-sawn or otherwise or how it ranks in the advisable or not chart (Oak and Ash being at the top of the chart).
In the spring of 2019 I made a steam chamber from redundant aluminium ducting, put to good re:use after changing my extraction configuration last year. Inside I placed two aluminium poles and the timber stock sits on these with very little contact – allowing good steam circulation. Although the chamber gets very hot to touch it circulates the steam well and I am able to manage how much steam is contained and how much is released for pressure control.
I have experimented with some very tight curves but even on very thin stock, the lacewood snapped when pushed towards 300 degrees. So many splits and snaps! However, the dressing table now being made to show at the London design Fair has gently curved leg rails and mirror stand, and this curve proved no challenge and with a simple dowel jig (rather than a comprehensive forma), the rails came out as intended.
I love this technique so much that I intend to build a 2m long steam chamber and although I wont become Joseph Walsh overnight, I think I have enough of a handle on it to work on some more ambitious projects (in Ash!)