Monday, 15 February 2016

More Splicing Igor!

While I was on a roll I did two more, the quality of my sawing and preparation was improving. Getting the back of the billet relatively flat and true helps to get a good clean cut, but even so it's tricky to cut out the bottom of the V groove cleanly as the blade wanders in to the first cut. One good trick is to gently drag the billet out from the blade as it is running, pressing the wood lightly against the blade, this will act more like a blunt rasp than a saw and will remove small amounts in a controlled way. It's easy to mess up a splice especially if you drop a billet on the floor and snap off a thin bit from the tip... (whoops) fortunately it is pretty easy to saw an inch or so off the tip, re mark it and do it again. That's just one more reason for leaving billets etc a bit over length.

My best two half logs were destined for a warbow stave but I got a nasty shock when I looked at the best bit... There was a nasty chainsaw nick across the sapwood right in the middle... drat. The other half had a big knot on one edge, but was good for one billet.

I studied the nicked half for some considerable time whilst moaning about chainsaws under my breath. Eventually I decided to try for two billets by cutting down through the nick, but making sure I had one good one. As it happened, that's pretty much what happened, one is good, the other (the left one ) is marginal for maybe a light bow. Mind it's always deceptive trying to judge how much clean timber there is once the sapwood is reduced and the billet narrowed to bow width, still, worst case is it'll make firewood.
Talking of which, the area behind the bandsaw is now littered with thin offcuts where I've gradually reduced the wood. That will make some nice kindling for my big Sis' wood burner.

With the warbow billets I marked out the Z splice as 6" long and 40mm wide. I went for extra length as my "Warbow Explodes" post (where the sapwood failed at the splice) is the most viewed post on the blog. I usually go for 4" and 30mm wide for more normal draw weights.

You can see the remains of the masking tape on the splice, I wrap the tape round to help the glue say in place and fill any small voids, also stops it running out and making a mess. For perfect fitting splices you can steam or boil them and clamp them up, once cooled they will be a perfect fit. I just try for a good fit by repeated fiddling and fettling, with rasps, files, bits of old saw blade and lots of holding them up to the light and patience. It's easy to think you have a good fit, but then you look at the back and find there are gaps on that side. On the plus side, with a taper fit, sometimes just a tiny bit of wood removal at a tight spot will allow the joint to push in much further.... did I mention patience?
 I then clamp 'em once they are glued, fine gaps up to the thickness of say a business card are ok, and bigger ones are ok if they can be squeezed closed with light pressure.

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