Saturday 1 March 2014

Repaired Yew Bow & Testing The Spliced Bow

It's been a busy couple of days, the more work I did on the repair bow, the more I wanted to give the sorry thing a new lease of life. I'd already removed a good bit from the last third of the top limb and some from the end of the lower
I was given carte blanche to go ahead and experiment in an attempt to revitalise it.
I heat treated and straightened the inner half of each limb. While I was at it I noticed the bow was actually about 0.5 mm thinner at the end of the grip than it was for the next few inches up the limb! That is just madness, so I rasped off the high spot and blended it all in. I also noticed a knot with a semicircular pinch alongside it. I though I'd pick at the knot and fill it if it was weak.



During heat treatment it became obvious the knot was loose and it popped out.
I'll let you see the results from the before and after pics and judge the results for yourself.
The tiller is much better, still not quite as circular as I'd like but it's a wise man who knows when to quit.
If you compare it with the picture from a few posts back http://bowyersdiary.blogspot.co.uk/2014/02/the-wisdom-of-waiting.html it's the same draw length and you'll see the draw weight is actually a whisker higher and the tiller is much better. I've noticed that it was being shot with the arrow pass actually on the grip, I realised why when I measured and found the grip was dead centre rather than 1" above and 3" below the centre line. So the nocking point and arrow pass made sense.
The difference is very obvious when trying to string it... I can't ! I've had to cut grooves for a stringer into the horn nocks, while I was at it I removed more dead weight from the nocks, they were riduculously oversized.


This morning I took the spliced Yew bow to the club and shot 18 3D targets and also shot it for distance. I had planned on taking a flight arrow but forgot.
It shot my standard arrow about 160 yards and the 30" ones a few paces more. I think it would have made the 180 yards for clout with flight arrows. 
Shooting at the 3Ds in the woods the bow performed really well and I shot pretty much as I would with my regular field bow 'Twister' . One of the other guys shot it too and was impressed. I took some of the shots with the longer arrows which felt odd as my anchor was near my right shoulder... I still got a couple of hits like that.







2 comments:

  1. Nice repair work, Del. So even though you took some material off, it has about the same draw weight- would this be due to the heat treatment?

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  2. I think it's all 3 things working together.
    Heat treatment hardening the belly a tad.
    Taking out the set restores the 'early draw' weight.
    Re-tillering to prevent it just going back to how it was before.
    Conventional received wisdom tells us. "Once a bow has taken set you can't recover it because the cells of the belly are crushed".
    I believe the heat effectively plasticizes the wood, allows it to be bent but also hardens the resins in the wood so when it cools the crushed cells are re shaped and stronger.
    Without the re-tillering the cells would prob' crush again as there are subject to undue strain due to the poor tiller.
    The results are very much in line with what I found on the "Hickory Challenge", that bow is still going strong, and hasn't returned to it's previous sorry state.

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