Saint Ambrose

Saint Ambrose
Photo: Journey Worker Productions, CC SA 3.0 (C)

Tuesday, 11 February 2014

Notes on hardwoods and organic wood sealers

Public Domain

I was recently visiting the family home, and talking to my father, who has been experimenting with wood sealers and repellents. We got to discussing Western Australian hardwoods, and he showed me a copy of a reference work, shown to the left.

This text from 1906, abridged 1917, is one of the industry's standard reference works for such timbers.

Up to now, I've been using Jarrah for projects. I like its strength, hardness, colour and its anti-fungal properties; I also like to get woods from my home state of WA. But, it would also be nice to find an alternative to some Casuarinas that I also wish to try out at some stage. 

Anyway, the book, pretty short, had the following points of detail (Cal, you are not kidding about the details; and, as a forestry technician in a previous life, I'm with you on this one--but readers should hear about your patented process for weather proofing wood sometime):

First, the author is concerned to establish scientific testing procedures for hardness and tensionability (real word) and so forth. Testing methods are given and sample sizes are in the 100s or 1000s. (The statistical side is otherwise a bit average, literally: only averages are given, no Standard Deviations and no Medians). 

What comes through, from the choices of examples and illustrations of use, is that the impetus for this science is to regiment, 'resource-ify' and organise timber harvesting for railroad sleepers. If one thinks about it, a house builder can work around timber to a certain extent; he or she can pick and choose stock. But, a railroad builder needs 1000's of homogeneous sleepers with no surprises and little variation from an established 'spec'. (So do the railway passengers.)

So, the railroads pushed the wood industry into getting seriously scientific. The Department of Railways supported the work. The other industries that needed wood reliability were communications (telegraph/telephone poles), shipbuilding, and - more sporadically but urgently - the mining industry which needed bracing during expansion booms.

Second, the work mentions that it is modelled on Johnson's Materials of Construction, which did the science on US timbers. It also rebuts Sydney researchers, who early on put down WA timbers as unsuitable for use (p.14). One wonders if this earlier literature might have saved, for a time any way, certain WA forests from plundering for trade. 

However, there is evidence that all types of the timbers were being in use already on the railways. Jarrah had been used as far away as Newcastle for some 20 years (p.47). There was at least an established trade in hardwoods from the eastern states of Australia to California in the 19th century ( 

Third, I discovered a wood I'd seen but didn't know the name of, Yate. It is one of the really hard scrub eucalypts. It is recorded in the text as having a hardness of 7500 PSI, compared to Jarrah at 4500. (I'm not sure how meaningfully accurate  these numbers are). 

However, it is difficult to dry and takes a much longer time to drop down to the standard 12% moisture. There are also brittleness issues. Still, I'd like to find some and try it, even if for a small bookshelf. Looking around, it doesn't seem to be sold anywhere. 

Has anyone heard of it or know where to find it?

In any case, it is good sometimes to stumble on to these old books. They can give you a bit of perspective.

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