RATIO OF STRENGTH TO MASS IN WOOD SPECIES

[bigbob]

Appreciate your answer dennis, while Black wattle's properties may be negated by the superier influence of glass, then the same would remain constant for any timber used. The use then would be from an aesthetic viewpoint and a desire to utilise native timbers. I appreciate that the values you are compiling are of utmost use to those machoscistic types[ ] who, when not practising self flagellation are endeavouring to construct a self bow. I am making a feeble attemp at humour, of course.Your efforts in all things bowyer related are much appreciated. Bob

[Dennis La Varenne]

bigbob,

Nothing wrong with using it for aesthetic reasons in a glass bow at all. However, for purely mechanical benefits in a glass bow, I would go for light weight for high limb speed coupled with a high shear-stress resistant factor. The ability to take glue well is also a factor as in a wood which is not oily for instance.

[Stickbow Hunter]

I have made one of my glass composite bows with what I believe was Black Wattle. I was given the lams and I decided not to use them and actually threw them out and they sat out in the weather for quite awhile. A mate saw them and said he would like a bow made from them. Without him knowing I made a bow with them and gave it to him for his birthday. The Wattle actually made a nice looking bow and it shot quite nicely.

I agree with Dennis about using a limb core with a lighter mass though.

Jeff

[bigbob]

Thank you Dennis and Jeff. Guess its destined for a doorstop then.

[Dennis La Varenne]

No, I wouldn't waste it.

You can still make a glass bow from it or you could have a go at making a selfbow. Just because it is moderately heavy.it compares with old standards as Rock Maple, Yew, White Ash and Elm, all of which have been used in laminated glass bows at some time. You seem to be presuming that just because it has a bit of weight, it will not shoot well and that is not necessarily true at all. The difference in speed won't be tens of feet per second.

It is just that on average, the lighter woods are quicker because of lower limb mass. Jeff uses both Bamboo and Red Elm which are quite light and shear resistant.

You could always have a go at making a selfbow if there are no sap pockets through it. It does make a good one by the accounts of others on Ozbow in the past.

[greybeard]

Bob,

I have used black wattle??? [common name] in a laminated longbow and I was surprised at how good it was when used as core material and the colour of the wattle comes up nice when used under clear glass. Used as a thin verneer under clear glass with bamboo should work well. It is also good for handles/risers.

The only downside is the damage caused by grub infestation making it difficult to cut undamaged laminations.

If you have a suitable billet a selfbow would be worth a try.

Daryl.

Perhaps another thread should be started where members can post their experiences of the various timbers that they have used. Over time this could become a useful resource. The addition of photos, i.e. leaf, flower and bark to aid in identifying certain species would be a bonus.

[yeoman]

Is this Black Wattle creature also known as Blackwood?

Dave

[bigbob]

Love your idea of relating practical experience with our native timbers Daryl, this could be a really useful thread. Re the black wattle /blackwood question it seems there are more than one or two trees that in certain ares have obtained the common name, black wattle. As to specific identification that would require direct comparisons between , bark, flower etc.I will be seasoning the log I have and doing some experimenting with it at a later date.

[Dennis La Varenne]

Dave,

Blackwood is one of the aka's for Black Wattle (Acacia mearnsii) which is why I like to provide/use the botanical name. Botanical names mean only one thing.

Blackwood is also the common name for Acacia melanoxylon which is another species again. So there are two Blackwoods depending upon where you live and whom you ask.

[Dennis La Varenne]

To everyone,

I have altered my table to include Blackwood (Acacia melanoxylon) in addition to Black Wattle (Acacia mearnsii) so that it is clear to everybody that the two are different species even though the names are often used interchangability.

Bootle comments on Blackwood that it grows over most of the eastern States, but commercial grades and quantities (those used for testing one presumes) come from the damper areas of Tasmania.

It can be seen from the tables that Blackwood is far inferior to Black Wattle in mechanical properties.

I have also altered the title of the PDF slightly and excluded the numbering which is a pest to change when adding or deleting listings.