Monday 23 February 2015

Loads of Work

Both bows are progressing nicely.
The 50# longbow is behaving it's self now and I'm now doing the horn nocks.
My first test after the heat treating and minor sideways correction showed it pulling 40# at 24" . Some arithmetic shows this works out at about 49# at 28".
There was a funny noise coming from the bow, which is why I only took it to 24", but I think it was just the temporary nocks snagging the string, I cleaned 'em up and simply drew it to 28"...
Sweet as a nut!
I'm moving the top nock down about 1/4", it may help the draw weight a whisker and will just balance the limbs a tiny bit better... to be honest it's more about fiddling than logic. It takes out a tiny bit of the knotty area on that limb, which will look rather fine when it's polished up. The top limb has all the character in it, the lower limb is cleaner.



The RD Flight bow is looking good, I still had to do a slight sideways/twist correction one one limb. I have plenty of tip width to play with to tidy up the limbs to match the string line but it's pretty good now.
the pics show it braced, the string line and how I jigged it up for the slight sideways correction. I pushed the limb tip across about 3/4" and after correction it had settled down to about 1/4 - 1/2" shift.
You can see how the side pieces of hardboard contain the heat and direct it along the belly.

Hopefully I'll press on this afternoon and get the horn nocks done on the longbow and get it cleaned up ready for some testing.

Just got the top nock done. I couldn't resist buffing it up to see the feature knot.... mmmm nice.

For pities sake! Some bows are more trouble than they are worth... I put it on the tiller, just working up to 28" and I hear a CRACK! I let it down quick.
At first I thought the sound was one of the handle blocks popping, but close inspection revealed there's a fracture on the belly by a knot. Damn,
The bow is still sound, it didn't collapse, that's the beauty of Bamboo backing, it holds it all together.

I've rasped out the offending knot/crack over about a 3" length and down to about 1/3 the depth of the belly. I'm going to cut a suitable patch, heat treat it and glue it it... one hell of a lot of work. It will be a great bow when it's finished but one that I almost wish I hadn't started!
I've got the patch made and heat treated. I'll glue in on in a minute when it's cooled. I have a theory that maybe the heat treating and lateral correction stressed one of the small knots, because that's the area where both heat treating and lateral bend were done. I'll make sure the bow is clamped up nicely in line when I strap up the patch.
I'm sure it will all turn out fine... it's just odd how some bows almost make themselves and other you have to drag 'em kicking and screaming into a finished bow.

2 comments:

  1. Do you have a system or method of matching the patch to the hollow you rasp out on the belly? How do you get a nice glue line with two curved surfaces?
    Thanks
    Don

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  2. Hi, I get an off-cut with the grain running the same as the wood in the bow limb. I cut it curved on the bandsaw and get the curve about right on the belt sander. The curve only runs in one direction, like a flat steel rule that is being flexed, with just the simple curve in one direction it's not too hard to get a reasonable match. I make sure the patch isn't too thick or too much oversize, that way it can flex a bit to conform to the shape that's been rasped out. If I have a slight gap at all I'd rather have it in the middle, that way, as the patch is pulled down with rubber strapping the thin ends (which are more flexible) will be a good tight fit. If you do a search on the bog for "belly patch" there are several posts with longer explanations. I first tried the technique after seeing it on a load of Victorian target longbows in a museum. It was a real eye opener, those bowyers certainly knew their stuff. I sometimes need two attempts at getting a well fitting patch, but it's surprisingly quick once you've done it a few times. A few weeks back I did a Hickory back patch on a bow for a friend while he watched.
    http://bowyersdiary.blogspot.co.uk/2015/01/back-patch-for-friend.html

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