I'll show you my crack - osage orange selfbow

[Mick Smith]

I bought myself a semi-finished osage orange selfbow stave at the Black Griffin 3D shoot recently. The material had already been removed from the back of the bow to a single growth ring, when I bought it. All I had to do was remove timber from the belly of the bow and then tiller it and finish it off.

I must say, it was a very enjoyable experience. I removed heaps of timber from the belly of one limb and bearly any from the other in the tillering process. I ended up with one thick limb and one skinny limb, but the tiller was reasonable in the end. There is a very slight hinge on one limb, the lower limb, but I've left it as it is, as the draw weight was already getting too low for my liking already. I was hoping for something around 50 to 55# and already it was only 43# @ 28 inches. I brought up the draw weight considerably by simply cutting about 1/2 an inch of the end of each limb and cutting new string grooves. This increased the draw weight to 48# which I was happy with.

I noticed when I was sanding the back of the bow slightly before applying a clear laquer, that there was a very slight crack on the back of the bow. The crack only became visible when it filled with sawdust. The crack is so slight that you can bearly feel it with your fingernail. I suspect that it's only very shallow, but I didn't try to sand it out as I didn't want to sand through the growth ring and besides, where the crack was, it was already in a depression in the surface, where there was little enough timber anyway.

Once the bow was tillered, but as yet unfinished, I decided to try it out in the backyard. It shot quite well. It had a little handshock but it wasn't too bad. It spat the arrows out like you might expect a 48# bow would.

The crack didn't get any bigger after shooting the bow about 10 or 12 times. But still, it continues to gnaw at me. Is the bow suddenly going to let go and break at this crack? Is there something I could do, to minimise the likelyhood of a failure occurring at this crack?

Oh, and by the way, the crack is exactly where the slight hinge is, on the lower limb, which probably will increase the amount of stress on this particular point.

Do I just keep on shooting the bow and hope for the best? Or do I try to bind this section of the limb with something to strengthen it? Or do I hang the bow on the rack and start building another? What do you reckon?

Mick

[DylanK]

Dont know what to do with the bow, but sure is a good title

Dylan

[TEX]

Wrap it with raw hide and hang a few feathers of it and no one will know.
It will look great. Should hold for a while.

By the way nice crack

[danceswithdingoes]

back it with sinew, silk or carbon

[Coach]

Either way .. I would say it is doomed for failure , but good on you for having a go Mick

[Trad Bound]

Nasty looking crack get some cream from the chemist.

Seriously contact Dennis La I'm sure he will have some words of wisdom.
Good luck
TonyJ

[Mick Smith]

Thanks for the advice fellas.

It would be such a pity to lose this bow, as I've sort of become very attached to it. It has heaps of character.

I only wish the whole bow was composed of the same timber as the top limb. The top limb is bright yellow osage and it was a delight to work with. It's extremely springy and strong. The top limb is only half as thick as the bottom one. In comparison, the bottom limb is almost like as if it's a different timber. It's much darker, probably more heartwood as opposed to the bright yellow sapwood. A bit like comparing spring steel to wet spaghetti.

You might wonder why the different in the limbs? Well, the bow is composed of two billets, which are spliced together in the middle. The limbs don't match up too well though.

What I would like now, is a complete bow made from the bright yellow wood. I think it would be a pleasure to build and I suspect it would perform very well indeed.

I'd like to back my current bow with snake skins. They look great, I reckon. Perhaps this might assist with the longetivity of the bow.

Mick

[longbow steve]

Hi Mick, Cracks can be ok running with the grain although the hinge in the same area may cause concern. I have board bow that has cracks length ways that I bound with serving and they didnt move, maybe they wouldn't have moved anyway.
The sapwood on osage is white so your billets are from different trees or at least different parts of the same tree. Osage darkens to a rich brown orange as it ages and is bright yellow when fresh.
Shoot your new bow and enjoy and learn from what it is sharing with you. Steve

[kimall]

Cracks with the grain will often fix up fine with running some supere glue into the crack by flexing the bow slightly in a way that opens the crack ever so slightly and squeeze a bit of super glue onto the crack and it will suck it right in there.When dry sand it back and you will be good to go often for a long time.Many many self bows shoot for many years held together with this method.I had a custom bow come from the states some years ago and found on arrival it had a small crack in the shelf on the riser when I rang the bow maker he just said "Thats fine just run some super glue right on in there" I told him I was not happy with that and sent it back but it is a very common practice.
Cheers KIM

[Mick Smith]

Once again thanks for the good advice guys.

Thanks Steve for teaching me a little more about osage.

Come to think of it, I've heard about the 'old superglue trick' before. Thanks Kim, I'll give it a go. It won't take much effort to do and it might just happen to fix it.

I am encouraged too by the fact that the crack didn't get any bigger after a dozen or so shots.

Mick

[longbow steve]

Hi Mick,

Hi Steve, Tell that geezer on Ozbow that his bow is in no danger of breaking from that crack. Only dangerous if it was near the edge of the limb. It doesn't need any wrapping. Hinge is more important. Get a pair of calipers to check the taper of the limbs to see if there is a low spot, or it was just a kink already in the stave.
H

This is an email from Hamish Casimir, he doesnt post on Ozbow but is vastly experienced with Osage, Yew and everything selfbow.
Steve
Geezer

[Mick Smith]

Thanks for that Hamish and Steve.

There is a low spot on the back of the bow, right where that crack is. It's a natural depression in the contours of the growth ring on the back of the bow.

This was my first attempt at tillering a bow and in retrospect I should have left more wood on the belly or made the limb slightly wider at this point to compensate for it, but I didn't.

In my view, the hinge is slight, so I haven't tried to fix it, mainly because I don't want to go chasing one limb and then the other to get it right. The draw weight of the bow is already lower than what I wanted.

I'll take some photos of it strung and at full draw, so you will be better able to judge the tiller and more importantly the hinge.

I don't mind being called a geezer.

Mick

[Mick Smith]

Here I was thinking the bow was pretty well tillered, but after looking at the below photos, it has become obvious that there is still some work to be done.

The bow doesn't look too bad when strung or even at a partial draw, but at full draw it's obvious that I'm going to have to take some more wood off the left hand limb (bottom limb) from about halfway along to just short of the tip. It's badly out of tiller at full draw.

You can see the hinge quite clearly. It's on the left hand limb about 6 inches from the riser. If I take some more timber off the remainer of that limb, I should be able to fix it okay.

When I first drew the bow to full length, I didn't spend enough time to study it close enough, as I was concerned about the bow taking a set or even breaking. Taking a photo of it, is a good way of studying it for a much longer period.

Mick

[TEX]

Hey Mick baby
you could use a grid on the wall system.
Just an idea
Tex

ps be careful with your crack mate.

[longbow steve]

Looks great regardless Mick, I see what you mean about the colours in the billets.
Hopefully Glenn, Dennis, Daryl can help you out with advise for the adjustment in tiller and yes photos do help in the process. Steve

[greybeard]

Hi Mick,

For a first attempt at a selfbow you have done very well.

I agree with others that the crack is of little consequence and the hinge would most likely be the cause of limb failure.

Ideally bush billets need to be spliced from twins i.e. side by side.

As you pointed out you should have left more wood on the ‘dip’. It is a little difficult to gauge by the photos as to how much taper ‘back to belly’ was used.
If the wood in the hinge has retained its integrity you could bite the bullet and make a kids/youth bow or de-crown the stave and back it with hickory or bamboo and re work the belly.
Backing the bow with a flexible medium such as animal hide will not eliminate the ‘hinge’ problem.

In either instance you have the opportunity to save the bow.

Daryl.

[Mick Smith]

Thanks Daryl.

What about taking some timber off the belly of the left limb, about halfway along the limb to lessen the hinge effect? I think this would have the effect of taking some pressure off that hinged area.

I could address the loss of draw weight be simply cutting the bow a little shorter yet again, only an inch or so. I could also adjust the taper, so the tips wouldn't be as thick.

Do you reckon this might work?

Mick

[Stickbow Hunter]

Mick,

I would do as has been suggested, use super glue on that crack. Make sure the glue is very runny and it will seep into the very ends of the crack. It should then no longer be a problem.

The left limb is a real concern and needs fixing IMO. The mid limb section is very stiff and needs wood taking off or I feel the bow will fail at the hinge. Take it slow and it should come good. You will have to then take some wood off the other limb to match them up again though.

Looking at the photos the limb tip looks very wide; try narrowing the tips down to 12mm or so and if you want more weight shorten the bow a little. A rough guide is you will gain around 10% in weight if you take an inch off each end.

All the best with it.

Jeff

[Mick Smith]

Thanks Jeff. What you have suggested is exactly what I intend to do.

Mick

[longbow steve]

Hey Mick, Narrow the tips first before tillering the belly as it will have an effect on the tiller of the outer limb. Steve

[Mick Smith]

Thanks Steve, that makes sense. I would have probably done it last if you hadn't let me know.

Mick

[greybeard]

Hi Mick,

You may have to make a compromise on the desired draw weight. Once you have reworked the limbs and brought the bow into tiller the poundage drop could be significant.

Prior to reducing the length of the bow to increase the draw weight you will have to try to evaluate the integrity of the hinge section in relation to the bows length when shortened and the draw length.

Either way .. I would say it is doomed for failure , but good on you for having a go Mick

Don't let negative thoughts prevent you from achieving your goals.

You can have a working bow even though it may vary from your original concept.

Daryl.

[Trad Bound]

Gee this Mick Smith bloke was quite for a couple of weeks, mate he's made up for lost time in the past twenty four hours.
Good on you Mick keep em thinking.

[Mick Smith]

Hi Tony

I've been laid up at home with the flu all this week. I'm starting to go stir crazy.

Not the swine flu, at least I don't think it is. I'm pretty well over it now though.

Mick

[ichiban]

i would say that you run some super glue into the crack and with vertical threads of linnen or silk (thick stuff from habadashery shops work well) patch the aria of the hinge and crack and feather the patch to zero 2 or so inches after the problem spot. oh and set the patch in titebond 3 or something like that. its worked well for me in the past

[Glenn]

Mick, your eyes can play tricks on you when you have a bow up on the tiller tree, when you have had a look at the tiller always turn the bow the other way around and pull it down again to have a look at the tiller before correcting tiller as it is very easy to to do the wrong thing when only viewing the bow from the one side. That crack is no problem if it is filled with super glue and I dount it would be a problem even of you didn't glue it, but the hinge can become a problem. Osage responds well to heat, place a block under the hinge and a couple of clamps either side of the hinge about 18" apart, heat the hinge area with a heatgun and bend the hinge the other way and then leave it there to cool and set, you may have to have a couple of attempts but the heat treatment does work well with osage...Glenn...

[ichiban]

hey thats a clever idea for fixing a hinge didnt think of heat treating it

[Glenn]

Ichi, I've done that plenty of times, it works real good, you can straighten out a stave using heat as well...Glenn...

[ichiban]

i was just reading over an earler post about some of the bow being sap wood possibly, which if it is then you have pulled of a merical as osage sapwood sucks all round.

[Stickbow Hunter]

which if it is then you have pulled of a merical as osage sapwood sucks all round.

I have seen it used in bows quite successfully mate.

Jeff