Aussie wood for bows

[shrimp]

Hi everyone
I am new to making bows and I was wondering what aussie timbers would make good self bows and how i should treat each timber, i.e. whether i should use the earlywood or latewood for backing, what concentration of earlywood and latewood I'm looking for and which design would help me get the most out of the stave. I live in the western suburbs of Brisbane if that helps at all.
Thanks in advance for any help.

[perry]

shrimp. this question gets asked a lot on this Forum, use the search and you'll find a very comprehensive list.

Start with readily available Floor Board Timbers from Hardware Stores like Spotted Gum and Grey Iron Bark. In fact a great many of the Eucalypt and Wattles are excellent. There's Crows Ash, Moreton Bay Ash, Mulga, Brigalow, Lancewood, Gidgee etc. The 2 Soapwoods Pink Ash Alphitonia Petriei and Red Ash Alphitonia excelsa are very common in Sth East Queensland and excellent Bow Woods.

In my experience there is little need to worry about Sap Wood Heartwood Ratio's with Aussie Timbers. Aesthetics is the only reason you would thin the Sap Wood. The Sap Wood on the likes of Mulga and Brigalow has very very fine growth Rings. Not that it matters - I have seen Sap Wood thinned with these Species with zero regard for chasing a single growth ring and the Bows are very safe.

There is a lot of introduced Bow Timber growing in Australia, Osage Orange and Black Locust grow from one end of the New England to the other

Any of the Woods above and dozens more make excellent Selfbows. Lots of Folks make Bamboo Backed Bows with these Timbers also

regards Jacko

[hunterguy1991]

What Perry said

[cmoore]

I was waiting for the two maestros of aussie bow woods to chime in

[greybeard]

Hi Shrimp,

If using Aussie hardwoods I would suggest you start with a basic flat bow design. As you develop your bowyer skills you can try more adventurerous designs.

Remember this old rule for selfbows; for n to n length double your draw length plus 20%. For starters it may not hurt to go a little longer as you can shorten the bow at a later stage.

Enjoy the bow making journey.

Daryl.

[perry]

I was waiting for the two maestros of aussie bow woods to chime in

they should be along any moment now------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------any time now --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------forgive me I'm a Child

Did a quick Search - here's a few random threads that may be of interest

http://www.ozbow.net/phpBB3/viewtopic.p ... ds#p154564
http://www.ozbow.net/phpBB3/viewtopic.p ... ds#p135123
http://www.ozbow.net/phpBB3/viewtopic.p ... +bow+woods

regards Jacko

[yeoman]

I feel I should have this typed out somewhere saved to just copy and paste.

I recommend that for a first bow someone should either use a split stave or a bamboo backed milled timber stave.

For selfbows, those made from one piece of wood, I have successfully used Ironbark, Spotted Gum, Tasmanian Blackwood, Silver Wattle and a myriad of others that I couldn't identify. Others have reported good success with Brigalow, Queensland Red Ash and a host of others.

For a bamboo backed stave, you can't go past a cheap board of Spotted Gum or Ironbark decking or flooring. With a bamboo backing almost any board of these timbers will do. The more swirly the grain, the more beautiful the end result.

[hunterguy1991]

Yeoman,

Id go even further and say make one using a linen backing on a decking board first to get a feel for tillering them... Its much cheaper, easier to apply and doesn't need fancy glue to put on...

Can paint designs on or leave it plain... even camo it if you wanted to!

Once you have your head around tiller and what to look for then start playing with boo backs and reflex etc...

I made 4 linen backed Spotty English longbows in the past 3 days, averaging about 3 hours start to shooting. Great fun little bows they are too!~

Colin

[yeoman]

What's the grain like in those boards?

I've had it convincingly argued to me that a thin linen backing is not as effective as people would believe, and that most of the protective effect is from the glue itself, not the linen.

Good work on those bows. You're making good time!

Still a little way to go. Bow before last that I made took about 90 minutes of actual work. Between bandsaw and final tiller shape required the removal of 0.6 ounces of wood, which didn't take long at all.

[hunterguy1991]

I tend to pick fairly straight grained boards when I can but I'm not overly picky about them... tend to go more for a darker colour in the Spotted gum because its usually a bit denser and make a heavier bow... Used the exact same dimensions for the 4 bows I made, 2 were of light coloured Spotted gum and 2 were quite dark... the light ones came in around 30-32lbs @ 28, the dark ones were 10lb heavier...

As far as linen for protection goes I beg the differ...

Brazilian teak warbow - 5 inch brace 115 at 24 (640x480).jpg (188.69 KiB) Viewed 6655 times

This was a warbow I was experimenting with made using Brazilian Teak (hit and miss, wouldn't recommend it) but in the photo is 115lbs @ 24" with a 5 inch brace height BUT it has a linen backing!! It lifted several large splinters underneath the linen (timber was not good enough) but it did not explode. Linen is tough stuff!!

Oh I forgot to mention, those bows I made were with nothing but a Shinto Saw rasp... no saws, sanders etc... just good old fashioned elbow grease. You should see the pile of dust I made! haha

Colin

[perry]

Quality Linen is excellent Backing. With a Strong Backing the grain only needs to be straightish. I have had Timber fail but never had a Plant Fibre Backing Fail.

The best Spotted Gum I have used I bought from Endeavour Timber. They had it Cut in a Plantation in the Northern New England. Have not bought any for Years - might have to chase them up again

regards Jacko

[yeoman]

I will continue to disagree than linen cloth backing protects a bow's back, and the evidence for it is in this very thread.

A linen backing will prevent a bow from shattering it's true, but it will not necessarily prevent splinters from lifting off the back. We've all had that happen. Here's why:

Very, very good wood will break in tension when subjected to 1% strain. That is, when it is stretched to 101% of its original length, the fibers break.

Linen will not start to stack until strained a few more percent than that. This s even more so when using a cloth where the fibers do not lay flat on the wood surface, but zig zag as warp and weft weave around each other. Tim Baker had pretty good success applying raw flax fiber as per sinew, and these would have been dead flat on the back of the bow.

So this means that when a bow's back is experiencing such strain as would rupture the wood in tension, the linen is not yet pulling it's weight as a backing. Add to this that linen cloth is fairly thin stuff usually, which means its thickness as a proportion of the limb thickness is fairly small. The outer 10% of a limb's thickness does 50% of the tension/compression. The smaller the percentage of the limb's thickness the backing is, the stiffer it has to be. Stiffness in this context means resistance to stretching. Sinew is not stiff in this respect, but sinew backings regularly run to a good few mm thick where it matters.

I'd posit that for a plant fiber backing, jute webbing such as that used for young trees or upholstery is much better for a few reasons:

- It's thicker, so makes up a greater percentage of limb thickness.
- Being thicker also allows for more glue to be used.
- The longitudinal fibers are not as distorted as much as the weft is most usually a thinner thread.
- It's terrifically cheap and easy to find.

If I were to use linen, I think I'd try to find a way to pre-tension it to get the best out of it, whether by holding the bow in reflex before gluing the fabric on, or making some sort of jig to apply tension to a strip of linen longer then the bow that you then glue and law on the stave.

I did some experiments a few years ago with wood samples (not bows, but this was more controlled and expedient).

From one board with violated grain I cut three samples. One I left bare, one I backed with a thick layer of PVA and one with a layer of West System (the only epoxy I had at the time). The bare sample broke early as expected, the PVA backed sample lasted a little longer, and the epoxy backed sample lasted longer still. I can't remember how the figures turned out exactly, but I could try to dig them out or worst case do the test again.

Goes to show though that a good glue painted on thick has some protective quality. I heard about a bow that either Jeff Chally or Dennis La Varenne made that was backed with a thick layer of PVA that probably would have otherwise broken.

So there you have it. My opinion with my reasoning for holding such.

Linen backings make for a terrific medium to paint and decorate though.

Cheers,

Dave

[shrimp]

Thanks for the help everyone, I did a run around my back yard to see what kind of trees i had to work with and there's some sort of gum tree in my back yard with a straight 2ish meter branch about 20cm wide and from what i could see from the bark it had a slightly wavy grain but it seemed to be mostly straight, would this be okay as a self bow or would it be better to back it with bamboo or just not go near it?

[greybeard]

Shrimp,

The only way to find out is to cut the limb, split it length wise into suitable sizes and put it aside to dry.

In the meantime find some milled boards, develop your bowyer skills, and in particular learn the art of tillering.

Better to mess up a board than a nice split stave.

Daryl.

[yeoman]

In what state are you, Shrimp?

[shrimp]

Queensland

[hunterguy1991]

Where in the sunshine state mate?

I'm close to Woodford and would be happy to help you out if I can.

Colin

[yeoman]

I was going to say: there're plenty of bowyer in Qld who'd be happy to help. With bowyers there's bow wood. Qld is ripe for it.

There are a couple of thousand species of eucalypt. The quality for bowmaking purposes range from 'superb' to 'might as well use pasta'. Unless you can identify the species in your yard, I'd just hunt for a timber seller and get some milled boards.