Wednesday, May 21, 2014

Gathering up a feast of Cape Lilac wood.

During my Green Woodworking adventures, I have been exploring woods suitable for use which are readily available here in Perth, Western Australia. While there is a long tradition of green wood crafts in Europe and North America going back over centuries, this is not the case here in Australia.

Consequently there are very little green wood crafts being done here - except for a few crazies like me. I am eager to share the wonders of green woodworking with other West Australians, but we need some friendly timbers to work with. That knocks out most of the gnarly eucalypts which predominate our forests and bushlands! However, parks, gardens and back yards offer a whole world of exotic tree species to chose from, so I am on the hunt for timber which is readily available, which splits easily, and is not too hard and unfriendly.

A prolific backyard exotic tree in the older parts of Perth is the Cape Lilac. This tree is also known in other parts of the world variously as White Cedar, Chinaberry, Persian Lilac, and more.   Known in the botanical world as Melia azedarach, the Cape Lilac happens to be a member of the Mahogany family. Mmmm... there might be some potential here...
One of the two piles of Cape Lilac trunk sections to choose from.
Looking in Gum Tree one day recently, (Gum Tree is an on-line equivalent to Craig's List in North America), I noticed someone offering the wood from some Cape Lilacs which were to be removed from their back yard in suburban Perth. These very kind people allowed me to take whatever I wanted from the pile left after the tree loppers had dropped the tree and cut it up into chunks.

Sadly, I would only be able to take one ute load of wood (only due to a lack of storage space!) so there was plenty to chose from. Some pieces I was able to lift (with difficulty) into the back of the vehicle. Others I would have to break down to make them smaller and more manageable. Time to get out the wedges!
I marked the line I had chosen to split the log, right through the pith.

Too big for the froe, a cluster of wedges driven along the line would get the split started.
More wedges to extend the split down the trunk.
Half a log = half the weight. Nice timber, two halves here of different logs.

Breaking down one half of the log again. Quarters, 5' 6" long.
There were a couple of other log sections which I also broke down into smaller pieces. Each of the log sections chosen and the way they were broken down were based on a list in my head. The planning for what I would be making starts with the log and how it is to be split down.
Breaking down a shorter section to create a couple of bowl blanks.

A couple more bits, and that'll be a load. That's a lot of weight too!
The next step was to take the load of logs home, where I would break them down further, to reduce the degrade. From the moment the tree was cut down, water has been leaving the saturated wood fibres. Breaking the log down into smaller sections would help to reduce the forces which cause splitting due to the cells shrinking as they dry.
Thanks to the tree for the gift of this wonderful wood.
I then took the load home for part 2 of the process...
Start a split and follow it along, one wedge after another.
Working on a pair of wide topped low saw horses, I pulled the logs and log sections off the back of the ute one by one and proceeded to break them down further. I had a "cutting list" in mind, based around a number of projects I am working towards.

Split completed - but some run-out on the bottom end.
Such an interesting wood, the Cape Lilac (referred to as White Cedar on Australia's Eastern Seaboard) also occurs naturally in some rainforest areas of New South Wales and Queensland. In Western Australia it has been grown for many decades as a garden tree.

The Bible of technical info about trees for Australian woodworkers is "Wood in Australia", by Keith Bootle. Originally published in 1983, it has been reprinted numerous times since. A book worth having on your book shelf. According to Bootle, the texture of the timber from this "medium sized deciduous hardwood" has a "course and uneven texture due to the ring porous nature of the wood. Grain straight". Certainly my previous experience and experience with this latest pile of logs confirm the straight grain suggestion! He goes on to describe it as: "Easy to dry. Collapse slight. Shrinkage about 2.5% radial and 4.5% tangential. Easy to work." In other words, pretty stable. He gives the Green Density as 640kg/m3 and Air Dry Density as 450kg/m3.  So it's dry density is similar to many of the Firs, Pines and Spruces found in the Northern Hemisphere.  It's pretty light and soft - in contrast to the many Australian hardwoods I am so used to working with! Bootle states that "the heartwood is probably not sufficiently durable for external use" and gives it's use as being for "internal joinery". He gives it's availability is recorded as "rarely cut".

Of course, Bootle is writing essentially for the Australian commercial timber trades - so there is nothing recorded specifically for crazy green woodworkers! However his info is always very interesting...

Cleaving off billets. I love the way this stuff splits so nicely!

Oooh, yum!

Nice split before the froe, even on a tangential line.

A whole bunch of spoon blanks, in small billets. 
There is an art to breaking down or splitting of logs like this. I have noticed that in the USA the term most commonly used is "Riving", whereas in the UK it is most commonly referred to as "Cleaving". Green woodworking has riven / cleft timber at it's heart. This is a fundamental skill.

Historically, logs were initially all broken down in this way, until transport systems were able to cart whole logs to more centralised saw mills. Before that, a log split in half could more easily be cut into boards by pit sawing. Here in Western Australia, billets cleft from jarrah logs were once shaped by broad axe and adze into railway sleepers, on the forest floor where the trees were felled.

There's something wonderful - almost primal - about the process of converting a log into billets of riven/cleft wood. It is also a process which requires a lot of skill. I did have a couple of challenges when cleaving the longer lengths of logs, with some run-out. What can take place is the split can jump across the fibres onto another line. A skilled person can "steer" the split with the froe, but I confess I am still in the process of acquiring that skill!

A bit of run-out on the far end.

Nice billets.

A bunch of cleft sticks which will hopefully end up making Sussex Trugs.
 I am lucky that winter is upon us. The weather is mild, it is raining every couple of days, so the moisture content of the air is high. This is good as it slows down the rate of drying of the timber, for the moisture content of the timber is seeking to come to equilibrium with the moisture content of the air around it. The rate of drying can be further slowed down, and therefore the end checking reduced, by the application of something on the ends of the logs and pieces of timber, to clog up the pores in the ends and seal them. In this case I used the stodgy glue in the bottom of a big pot of my favourite glue, Titebond III. You can also use thick paint or even the commercially available emulsion... but I had this gluggy glue in the pot which was too thick to pour out, and it made sense to use it up. I know from previous experience that Titebond III works really well for this task! 

A few bowl blanks, spoon blanks and some other shorts (leg material) with the ends sealed.
Despite the fact that I can't wait to start using this wonderful pile of  timber, it is just going to have to wait for a while until I have the time and opportunity to go to the next stage  - to start making stuff from it!!

In addition to using it for bowls and spoons, and experimenting with it for stools and Sussex Trugs, I am planning to use some of it to run the next Green Woodworking Course.
Watch this space...

Thanks to the very nice folks who advertised in GumTree and gave me the opportunity to collect this nice feast of Cape Lilac. Hopefully some of you readers in Perth may be able to come have a taste of the joys of Green Woodworking with me sometime soon!

No comments:

Post a Comment