Saturday, 13 April 2013

Experimenting With a Cracked Bow +Video

Now you'd think a cracked bow would be no good, but there are cracks and there are cracks!
This crack is square across the belly and about 1/4" deep (the limb is about 1" thick). The belly of a bow is in compression so does the crack actually matter?
Over night I'd been thinking about this, and fortunately I'd left the bow all clamped up.
This morning I flooded the crack with low viscosity superglue, unclamped it, put the tillering string on and tensioned it with a block of wood between belly and string. This closed up the crack and forced the glue into the crack.

You could make a bow with a bamboo back and a belly made of individual blocks stuck on as the belly but not stuck to each other, as the bow was drawn the blocks would all butt up tight against each other and it would work fine. In fact I think I've seen something like this on 'Scrapheap Challenge' or some program like that where they were building giant contraptions like balistas. I'm not saying its actually a good idea!

I've just tried the bow on the tiller and it looks remarkably good(ish). Now the question arises, should I just carry on with it or should I cut out the crack and let in a long curved patch? Which is stronger?
Anyhow, this crack gives me scope to experiment and learn a bit more.

The sun is out so I'll probably be pottering about in the garden. Off to a field shoot at Avalon Archers tomorrow.
The longbows are now done for the year so experimentation is just the thing, I'm also hankering to make a little native American short bow from Osage.
Update:-
I've had it back to over 70# at 28" !!!
Blimey, it's total madness. When I take the string off the crack opens up!
I shall cut out a long curved piece and let in a piece of already heat treated heartwood.
video



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