Why would you test a green piece??? I was wondering why Ironwood was so soft
Printable View
Timber hardness varies greatly from tree to tree. Some timbers are more variable than others. I have had the dubious pleasure of "working" both Lignum vitae and Bulloak. I would rather plane the latter any day.
The short answer is that I don't know. What I haven't mentioned is that the vast majority of species in Bootle"s book were tested both green and dry in most tests including hardness. There was only a hardness value for green timber with Cooktown Ironwood and in fact there was no other dry data except.....there was a figure for the dry density! Possible the data was lost. Who knows?
I agree with rustynail regarding the variability of timber and it is a brave person who categorically states the properties of any timber other than to say there is a tendency for this species to be hard of soft. Quoting exact figures and expecting them to always be the same is fanciful. An example of variability is that IanW has always had bad experience with Spotted Gum. I however really like it, although I conceed it is not without some problems. When Ian saw my Spotted Gum first hand he commented that it was hardly like his at all.
The Bull Oak and Hairy Oak I have found to be surprising easy to plane, but frequent sharpening is required. However there has been no "pick up" for example.
Regards
Paul
Good point, Paul.
I'll repeat my posting #8, adding density figures:
"...However, even with E globulus there are essentially three different "types" of blue gum on the market:
- Old growth - Hardness 12 kN - rich dark brown timber, Density 0.9,
- Regrowth - Hardness 10.5 kN - slightly lighter colour, Density 0.82
- Plantation - Hardness around 6.5-7 kN - much lighter colour, often similar to mountain ash, Density around 0.7...."
[Figures are from Bootle and Foerstry Tasmania except for plantation stuff which is a "comparative best guess" - I have been unable to find any actual test results for plantation E globulus.]
The obvious point is that the properties of one species can vary radically depending on where and how it is grown. Few recognise plantation Tasmanian blue gum as the same timber as its old growth relatives.
At least two significant marketers are quoting Bootles with full attribution, but omit to mention that plantation timber is radically different from old growth.
Alternatively one major marketer is blending significant amounts of plantation sourced E globulus into their Tas Oak product mix, and, essentially, nobody has noticed.
Cheers
Graeme
Hi Wafarer
Really interested in the chart, where is a copy that i can download or expand so that it can be read.
New to the forum !!
Many thanks
Hi Varra
I assume that you are refering to the above table laboriously extracted by Bushmiller from Keith Bootles Book, Wood in Australia. It is THE standard reference and if you are interested in Australian timbers you should have a copy; its not expensive.
Also, I doubt that Bushmiller would object to your copying his table.
Also a good reliable online international source is Wood Database.
The Wood Database
Also reliable, but harder to navigate are the websites of the various state forestry commissions.
Cheers
Graeme
Yes, I think Varra is referring to the table linked by FenceFurniture and the subject of the original post. However, Bootle's book is more relevant for Oz. There is a mountain of information in it and is highly recommended.
Regards
Paul