Friday 7 December 2012

Snow & Bamboo

Whaaaa, too cold in the garage to do much, but Over the last week I've started working on my Bamboo slat to back the spliced Oregon Yew heartwood.
The bamboo slat is a bare 6' long, I will go for a slightly wider flatter wider cross section than usual, but I may try to keep the depth/width ratio still withing the 5/8 rule so that it could be classed as a longbow. I'm not quite sure which archery society came up with the 5/8 rule but it's commonly accepted and isn't an issue with anything vaguely like a longbow.
I may glue it up with a hint of reflex, but I won't build in a narrowed grip or arrow shelf like ... well maybe I'll narrow the grip if it needs it.
I was a bit uncertain about sawing the Bamboo so I asked the guys on Primitive Archer (PA) what bandsaw blade was best,  it turned out the 6tpi (teeth per inch) blade I had on already was fine.
I started sanding down the concave side of the Bamboo slat to get it flat, even with the belt sander it was taking ages and was still pretty thick even when I'd flattened it out (6-7mm). One of the PA guys suggested 1/8" near the middle and 1/16" at the tips (approx 3.2 mmm and 1.6mm respectively).
With a lot to take off I tried my plane, first following more advice and making sure it was sharp. The belt sander was V useful for cleaning up the bevel on the plane blade prior to final sharpening with an oil stone.
First pic shows the 'boo taped to the stave after running through the bandsaw, you can clearly see the nodes and how it's concave.  I clamped the Bamboo to a piece of 3"x2" and planed it down without too much trouble. back onto the belt sander to flatten it off.
I'm roughing down the high spots  on the Yew heartwood with a rasp and then running it over the belt sander to even it off. I'm not going for dead flat, I'm allowing some longitudinal undulations to reflect the shape of the stave but getting it flat across the width of the bow. I'll glue it up soon.

Right pic shows the planed down concave side. On the outer face of the 'boo I have just taken the very peak off the nodes, leaving them still substantially proud, they look good standing out too and I think if they are taken down flush they can fracture.
Next morning I looked at the Bamboo again, hmmm it still looked a bit thick, and I could imagine that once it was on the bow and I started to narrow the limbs it would start to look thicker and thicker (due to the natural curve of the 'boo. this illustrates why I don't like to rush, we all do stuff and think, wow that's great, but by the next morning maybe we realise it can be improved. If I'd rushed to glue that up last night, I'd have been cursing myself this morning. Mind that's not to say it's right yet... still plenty of chances for me to screw up.
Oh, yes, and I've signed Brian's bow :)

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