Primitive Archer
Main Discussion Area => Bows => Topic started by: mikaluger (Mick Kay) on September 23, 2014, 09:10:29 am
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Just a little advice gentlemen. Spliced billet ELB I am working on.
I have this little knot right on the edge of an otherwise pristine backed stave, it is about a third of the way up the limb from the handle. I have not rounded the belly or the back yet, just cut tapers oversize and removed the bark. When i round the belly, I think most of it will be removed. It does not quite come out centre of the belly. The edge will still be exposed tho. Not sure how to continue here.
Thanks.
Mick.
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Hmmm, You have pretty good continuous sapwood on the back, so that should be ok.
A lot of the knot may well fall of the edge/belly, and knots on the edge aren't too bad...
It looks to big to remove and allow extra width on the other edge, but if you leave it in you need to make sure it is solid and neither loose nor surrounded by weak manky stuff that can compress and cause a pinch. (Grind a fine point on an old needle file and give it a damn good probing :o )
It looks sound on the belly, but as you work it down you may uncover manky stuff which can always be picked out and then filled with yew dust-epoxy mix. Or if there are fine gaps, it can be flooded with low viscosity superglue
Sometimes it easier to pick out a loose knot early and plug it rather than wait and try to fill half a knot.
The key question is ... is it solid and sound?
You will probably end up with a stiff spot there, but that's better than a pinch (IMO)
You may also find that you have to treat it more than once as you slowly work it down... better to do work twice and be safe, than cut corners and have a break/pinch etc
Dunno if that helps
Del
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Thanks Del, that helps.
The knot is sound, i will work it down slowly. Once it is rounded most of it that is left will be on the edge.i will fill any gaps that are left.
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If it really does look troublesome you can put a curved patch along the corner of the bow to give a run of clean wood along the edge of belly or back.
Plenty of examples on my blog, this sort of thing:-
http://bowyersdiary.blogspot.co.uk/2012/10/a-tale-of-two-yew-longbows.html (http://bowyersdiary.blogspot.co.uk/2012/10/a-tale-of-two-yew-longbows.html)
Del
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I'd leave plenty of wood on the opposite edge too. Can't put it back on!!!
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Hi Guy's,
I was dubious of this knot, and once I got it to low brace, the knot cracked. The black line shows where the crack is. :(
I had a look at Del's blog and decided to do a similar repair as I have no other choice really, it had to go! I have a nice piece of leftover sapwood and heart wood off the same billet that matches really well with where the patch will go. I hope it works, this is such a beautiful stave to waste.........
I will finish the patch peice and glue it up tomorrow, it's late here now. I'm a bit miffed really, Oh well..... onwards and upwards as my old man used to say!!!!!!
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Yeah. that looks a nice size scallop to have taken out :) ...
At the risk of stating the obvious, get you ring alignment the same on the patch as the bows. I ofetn end up making two patches before I get it right. Don't scrimp on spending time getting a good fit, get the patch down to somewhere near final thickness too, that will allow it to have some flex as it's strapped up gluing, and will ensure a better fit tah if yo uleave it V bulky and stiff.
Actually a belly crack like that may have been ok as its in compression, but any slight flexing of the bow the wrong way could have been fatal, and it was always going to be there irritating you... I think you have chosen wisely Grasshopper ;D
Del
BTW What adhesive are you going to use?
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Techni Glue Del, two part mix made here in Aus. Most bowmakers use it here, I used it on the splice joins also.
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And away we go.......
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Looks like you have it taken care of there. I have been lucky with knots laying exposed on the edge of yew, so far. I always saturate them with a thin CA glue, and tend to leave them a little smelled to keep it all tad stiff through the knot area. I am looking forward to seeing how this one turns out. Sorry those billets are giving you a hard time.
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No worries Carson, all good son! It's just one of those things.
In hindsight i could of turned the billet around and had the knot closer to the tip, letting me cut it out with the tapers. But I love a challenge!!!!!! ::)
Still stoked with the billets, it will be fine mate! This is Australia and I have Yew!!!!! ;D Rare as rocking horse poo in these parts........ ;)
Thanks again.
Mick.
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OK,
Here is the result of the patch, in the words of one of my mates, its "frankenbow"............. :biggrin:
Tillering tomorrow.
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Hey, that's looking a damn sight more solid, blends in pretty well too.
Double check on your epoxy how long to reach full cure, sometimes it's longer than is obvious.
Del
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Thanks Del, will do. 24 hrs usually is fine. Iw ill leave for another day tho, no rush......
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Wow great job Mick. Can't wait to see it bend :)
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Find a nice warm spot to cure it. If epoxy cures at say 100F it will soften at anything above that. But if it cures at say 150F it won't soften until it gets above that. It's getting into spring down there, maybe leave it in your car for a day.