The Tree of Heaven Project - Ailanthus Altissima

THE TREE

Ailanthus altissima /eɪˈlænθəs ælˈtɪsɪmə/, commonly known as tree of heaven, ailanthus or varnish tree is a deciduous tree in the family Simaroubaceae

Unlike other members of the genus Ailanthus, the Altissima is found in temperate climates rather than the tropics, and native to central and north east China as well as Taiwan.  From the 1700s onwards it has been cultivated in North America and Europe.

Its appearance most resembles the European Ash, with its pale, yellow white timber and its fans of pinnately compound leaves.

 PEST

The Ailanthus is not a popular tree, not amongst horticulturists and not among the random people responding to my social media posts and blogging.  It is extremely invasive when it is planted in non-native places it upsets the local ecosystems in numerous ways.  Not only does it propagate much faster than the native species it has crowded next too but also secretes chemicals into the soil to kill off its rivals and any animal species it might consider a threat, potentially leading to extinctions and/or negatively effecting bio-diversity.

In the urban environment, where our tree had been growing for 50 years plus, the tree can cast itself across various gardens and parks, causing the same problems as in rural areas plus it can hit the built environment.  Numerous cases have been recorded of the Ailanthus tree spreading its roots under the foundations of buildings, causing damag to the houses and also sewer systems and pulling up pavements.

Its quite a git.

The Royal Horticultural Society advises “If you already have these species in your garden or on your land, you are not likely to be prosecuted simply for having them. However, you are advised to control them and, for those 36 plants listed by EU, you are required to take all possible steps to remove them, even if you didn’t plant them. It is also your responsibility to ensure that they are not allowed to spread.”

EU Regulation lists the Ailanthus as an Invasive Alien Species. This legislation still applies in the UK. It lists Ailanthus altissima as one of 36 plants that you should not plant or cause to grow in the wild but in addition are banned from sale and gardeners possessing them should undertake measures to control them.  

The Tree of Heaven Project - Milling Day

I was back in Kensington today to help mill the Ailanthus tree that was felled last week. And by help I mean marking up pieces of tree with chalk and watching experts convert it into usable timber. I learnt alot today and I am optimistic that the yield has been maximised.

The mill and the Milling

The milling was hard going, the sapwood is very gummy, especially just beneath the bark and the chainsaws clogged and became blunt after two 2 metre passes. The mill operators were slowed down considerably and needed to return the following week to finish the job.

Shakes or cracks in the timber are the most common challenge when it comes to converting threes into usable timber.  Heart shakes occur along the centre of the tree, where it’s the oldest and most fragile.  The middle boards, and especially the very centre board is susceptible to this and when we placed our central board onto the sticked pile there was a very loud crack as the board parted down the middle.  Although this a challenge to the yield, the central board obviously very wide compared with the outer ones so two lengths of usable timber can be taken either side of the crack.

The other boards fared well with the exception of a few felling shakes at their extremities, and but only 10 to 15cm from the ends. Felling shakes caused by the trauma of the felling process

 

The Timber

As a European furniture maker, I know very little about the Tree of Heaven and in the next few weeks I endeavour to educate myself.  I had read that the timber resembled European Ash and was noxious when milling.  As we started to mill through the body of the trunks, the characteristics of this Ailanthus tree started to reveal itself. Although, the timber was not smelly at all when cut, the timber did indeed resemble the pale, grey-yellow of Ash.  The very heart is a golden brown and the sapwood paler than the main body but similar enough that some will be robust enough for use.

 

Yield

There are numerous blanks ideal for turning, especially those cut from the confluence of the limbs or trunk and limbs, where the timber is more colourful and varied in its figure. Elsewhere, there are potential greenwood working opportunities and at the bottom of the priorities, some rounds and odd shaped but small pieces for outdoor furniture. 

The Tree of Heaven Project - Felling the Ailanthus

Today saw the start of an exciting new project for 2021. This ailing Ailanthus, or Tree of Heaven, was chopped from a very narrow space in Kensington by the skilled chaps at The tree company.


Tree surgeons and crane operators are highy skilled legends.

After a good deal of consultation with me and the client, the tree surgeon clambered up and around the tree, shackling parts of the crown and cutting them free. These upper branches are unusable for timber so they were removed in two large pieces with brash and all attached. It was very dramatic to see what was essentailly a small tree pulling away and floating through the air. I stood and watched and nodded and gave the thumbs up and tried to keep warm in the cold January weather.

Then the surgeon worked his way downwards, applying precise cuts at positions we agreed to help maximise the yield while the crane company worked their magic. The communication between the crane driver and their man on the ground was amazing. The driver sat in the cab on the street, unable to see the tree, the surgeon or his colleague but managed to pull out all the material, including the trunk from its base from the small garden and onto the road without touching a thing. The client has a carport just below the canopy of the tree and not one piece of the felled tree touched it, let alone crashed through it, as predicted by many.

The chipper is a beast that snatches the brash and smaller branches and devours them. The background, bone crunching sound is a constant reminder of what usually happens to felled trees but also of the the triump of the day . Whatever we salvage of this tree is better than the greedy demands of the chipper.

The yield at first view seems larger than predicted, the tree is in good condition above the root. There is a little rot or disease at the base of the tree but it has been caught at the right time and only extends into the timber about 15cm.  The trunk of the tree was felled in two pieces at 220cm long, which as an initial observation is adequate yield for the proposed projects.  Desktops, for example can be made from the trunks, while the two major limbs will offer material for leg posts and narrow rails if they can be put in the kiln.  Further to that, I retained countless small rounds for turning blanks and making greenwood items for the garden.

Ebonisation process in three stages - London Plane Lacewood

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 London Plane Project - 3. Working with Lacewood & London Plane timber

Lacewood can be difficult to work and often traditional hand tools are most helpful in converting and shaping the wood into furniture and objects. The medullary rays leap in all directions and working the timber with machines can pull the fibres up and out - leaving deep unrecoverable tears. During the making of the pieces for the project I used a wire brushes, rasps and files, a cabinet scraper, a travisher, a spoke shave, bevel and gouge chisels and hand planes and hand saws.  However, where the character of the timber was less tricky I have used hand routers, router tables and the CNC machine for my final experiment.

 

Edges, Facets and curves

When shaping the dressing table in (mostly) wild lacewood, the hand tools came to the fore. I wanted to bring out many of the visual characteristics of London Plane in one furniture pieces. As well as hand cutting and chiselling the dovetailed drawers I used various hand planes to finish the edges of the top and hand carved and gouged certain areas to add a textural dimension.

 

Using the spoke shave

My favourite tool is the spokeshave, a squat two handed plane that removes material in a localised area. They come in both a convex and a concave profile. I use a convex profile to scoop facetted depressions into boards and legs.

In this video I am using the spoke shave to shape a curved facet on the inside leg of the dressing table.  I mark out accurately the area to work and with a very sharp blade, position correctly and held tightly.  I start removing material from the centre of the facet and work outwards from the centre towards the extremes, eventually working the whole length to create an even and smooth finish.  As I cut through the medullary rays at roughly 45 degrees, facets expose another weight of lacewood figure that looks halfway between the wild lacewood on the front face and the regular London plane on the outside face.