Ozbow

Found an a dead Tassie Blackwood tree at a friends house, we chopped it down and got a stave out of the centre of the tree. The stave has a few small knots in it, but the general grain direction is good. Do you think its a good material to make a self bow from? Should it be reinforced with something? I'm relatively new to archery, so I thought I'd ask on here.
Thanks, Miles

Miles Taylor wrote:Found an a dead Tassie Blackwood tree at a friends house,....... The stave has a few small knots in it, but the general grain direction is good. Do you think its a good material to make a self bow from? Should it be reinforced with something?......

Dead wood can be problematic, the best way to find out is to actually make a bow.

Daryl.

Tassie Blackwood is as far as I know the same as Black Wattle, which can be used for self bows.

You may run into trouble with the knots and possibly some pin holes but as Daryl said, only way to find out is to try it.

Colin

Thanks very much Daryl and Colin! Any dimensions I should follow? Do any of you have a link to a thread about self bows?

Thanks, Miles

Design depends on the type of bow you want to make...

I can give you a good template for an English style longbow if you wanted to go that way. If not just hunt around on the threads or search for some flatbow builds or selfbow builds. Plenty on here

Colin

Yeah that would be great thanks Colin!

Have a read of my thread " Basic English longbow for beginners" and look for a post by Dennis with a template. I use the width tapers he specifies in the template and a straight thickness taper from a 4" full thickness handle section down to half the handle width for rough stave, ie, if the handle is 25mm thick and 30mm wide, the tips will be a 15mm dia. Circle.

Hope that gets you started.

Colim

Cheers! Thanks so much for the help Colin!

No worries. Look forward to seeing what you come up with mate.

Miles,

A couple of quick questions;

What are the dimensions of the stave, particularly the length?

What is your draw length?

What draw weight are you hoping to get?

Depending on how much other blackwood timber you have to play with, if you can cut lengths of about one metre and shape them to various cross sections you can do some bending tests.

Generally I have found that the timber will dictate the style of the bow.

Daryl.

Cheers Colin.

The stave is 58 inches x 2 inches x 1 inch. My draw length is 29 inches. I'm hopping to get around 40 lbs +...

I experimented with a couple off cuts and it is pretty flexible once very thin. If tapered correctly I'm sure it will work alright.

Thanks again for the help Daryl!

Miles,

You may have to use this stave as an experiment and make a youth bow.

The general rule of thumb for selfbows is double the draw length plus 20%. which works out to just under 70" n to n. for your draw length.

Allowing for string grooves in your stave you are looking at 56" n to n. which works out to a draw length of just over 23".

The above is not cast in concrete but is a reasonable guide line to work with.

Two alternatives could be; [1] cut a sister stave and splice at the handle, [2] recurve the tips and sinew the back of the bow.

If you are going to persevere with the 58" stave making the limbs wider and thinner is probably the better option.

Having the bow bending through the handle will help a little.

Daryl.

Yeah, I have access to more Blackwood, so I think I will have a practise on this stave and see how it goes!

I might continue with the 58 inch stave, since I have it. So should I make more of a Flatbow? And should the handle thin out, so it can bend?

Thanks for all the help Daryl

Miles

Miles Taylor wrote:....I might continue with the 58 inch stave, since I have it. So should I make more of a Flatbow? And should the handle thin out, so it can bend?....

Miles, the dimensions in the diagram are a suggestion only as I can not physically handle the stave.

You may wish to play around with the 16" to 8" ratio in the limb. Thinning the handle back to belly will help. You will probably notice at about 24" in to the draw the limb to string angle will be about 90 degrees at which point stacking can start to occur.

To get a better understanding of the blackwood did it die from natural causes, poison, lightning strike, ring barked or unknown?

Daryl.

Thinning the handle back to belly will help. You will probably notice at about 24" in to the draw the limb to string angle will be about 90 degrees at which point stacking can stacking can occur.

Is this when its very hard to pull back?

To get a better understanding of the blackwood did it die from natural causes, poison, lightning strike, ring barked or unknown?

I think it died of natural causes. There were a few termites in the outer rings, not where the stave was from.

Thanks again.

Miles

Miles Taylor wrote:.....You will probably notice at about 24" in to the draw the limb to string angle will be about 90 degrees at which point stacking can stacking can occur......Is this when its very hard to pull back?...

Yes, you start losing the leverage effect. A short straight limbed bow will have a shorter draw length than a recurve bow with a similar limb length.

Miles Taylor wrote:......I think it died of natural causes.........

If you have access to some live trees it would be better to harvest these, cut some billets, seal and store to dry.

Daryl.

Great, thanks for all the help Daryl! Ill give it a shot and see what happens! I'll try to work around the knots.

Thanks, Miles

Miles have you started this yet?
A photo of the stave and a photo of the ends would help us to help you.....

Unfortunately, no haven't started it yet, been really busy with school.

But here is the stave and end.

Thanks

I had to split the photo of the stave because it was too big.

Miles,

It is difficult to make a qualified appraisal of the Blackwood billet from the images posted. I have circled areas that look to be suspect.

In the first image is that a knot, second image irregular grain pattern surfacing and the third image timber decay?

Ideally you need the grain orientation running as close as possible to edge to edge as shown in the fourth image. If you have access to Blackwood trees is it possible [if the trunk is long enough] to fell one that is about six inches in diameter and split it into billets for drying.

In the meantime if you wish to persevere with the stave you have it may teach you a few lessons, alternatively obtaining a milled board is another option.

Daryl.

Thank you very much Daryl,

That has helped a lot. Since I won't be at my friends house for a while (the one with all the blackwoods) I think I will have a crack with this one and try my best to work around the knots, and the discrepancies.

Excuse my ignorance, but what is a milled board, does it act as a backing or do you mean I should buy a stave?

Thanks, Miles

G'day Miles,

A milled board is a piece of timber that has been cut or dressed using saws or planes to get it all squared up... decking timber or furniture grade timber are milled boards.

Split staves are staves that have been cut as a tree and then halved or quartered (depending on how big the tree is) where the sap wood provides a single ring of growth to be used as the back of the bow.

I have played around with Tassie blackwood a little ( its a bit lighter in colour up here and a bit more orange) but I think if you can get a good stave from a tree with few knots and borer holes you would be able to get a nice bow from it.

The stave I had was seasoned for about 10 months and made a very heavy bow for a small size... ( about 25mm thick in the handle gave around 80lbs @ 22 inches)

Unfortunately this bow broke on the tiller as it failed on a very tiny borer track (quite spectacular when they blow up!! )

Look for good clean staves and I reckon you'll get a bow from one, don't be discouraged with any failures either, that's how we learn.

Colin

Thanks heaps Colin!

Great help! Did you need to season it in any special conditions?

Thanks, Miles

Somewhere dry and out of the way is a good spot to season timber.

Cheers Colin!

Miles Taylor wrote:.......Did you need to season it in any special conditions?......

hunterguy1991 wrote:Somewhere dry and out of the way is a good spot to season timber.

Miles, when you have the split staves it is advisable to seal the ends using a PVA type wood working glue. Slowing down the drying rate will help to minimise end checking. Cutting the staves over length will also help.

I usually apply at least two coats to the ends and a lighter coat on the split surfaces.

You may enjoy reading the following regarding bow making and associated equipment before the advent of the modern materials that are available today.

The Flat bow by W. Ben Hunt & John J. Metz, 1936.

http://www.archerylibrary.com/books/flatbow/

Daryl.

p.s. Eddie when I type the word bow with a capital B the smilie appears; Bow

Thanks Daryl.
I will fix this Bow as well as the new Bow I will have on the week end.

Eddie

Excellent, thanks very much Daryl.

A very interesting read.

Thanks, Miles

hunterguy1991 wrote:....Split staves are staves that have been cut as a tree and then halved or quartered (depending on how big the tree is) where the sap wood provides a single ring of growth to be used as the back of the bow....

Miles,

The following video, if you have not seen it may be beneficial in your bow making quest.

http://www.youtube.com/watch?v=4xdiiwO4UUc 1990 Bow Building with Al Herrin

When using Australian hardwoods a slightly different technique may be required when preparing the back of the bow but the overall principals of bow making apply.

Daryl.

Thanks Daryl, loved the video.

Great advice on how to work around the knots!
Also good how important it is for the grain to be straight!

Thanks, Miles