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240's sheep horn bow build with Tom Lucas
NorthHeart:
I want to pause a minute and really make a point. The splice was the first step that made me really slow down and pay attention more than ever, especially after my close call. Your splices must be good, or don't continue further until they are. When viewed from either side of the limb they must be even, not perfect but very close. Some small gap or "daylight" is ok, but only just a little bit, as the hide glue will fill this area when its clamped. Also, on my second bow i found it much easier to do the rough work by marking the horn and then laying it on a belt sander with a medium grit belt and applying pressure slowly and cautiously, checking my work frequently. Once you realize the spot where you need to remove material to close the gap, apply pressure only to that area. Or, clamp it in a vice and use a file or rasp for the fine fitment work.
If you elect to use a sanding belt, remember to rough up the surface with a ferrier's rasp or similar so it is not too smooth...this way the hide glue will stick. Tom calls this "giving it tooth".
NorthHeart:
Once your splice job mates up nicely the next step is to splice the handle together with hide glue. Tom uses a double boiler so that the glue doesn't burn. He also only used distilled or bottled water, never tap. Here is one part where i was too slow to capture a proper picture. He simply dips the one horn in at one splice surface(yes it drips messily down the other side, no worries), then he dips his bare hand in the glue and quickly coats the other side...and fastens them together with 3 small C-clamps. We use light pressure so that the hide glue just barely squeezes out. Do not use more pressure than just enough to hold them snugly together or you risk squeezing out too much glue. Within the time it takes to do this(30 sec to a minute) the glue is already starting to gel and harden up, Tom says this is ok. After you glue it up use a stick or your hand to spread more glue along all 4 side edge seams. Let it dry for a day.
Note-the first pic is without glue, use your small clamps to see ahead of time how its gonna fit together BEFORE you glue it up.
NorthHeart:
Now its starting to look like a bow! Note the natural deflex shape, ohh so pretty. Tom assures me that by the time the sinew is added it will attempt to pull it back into reflex, but that comes later. Be careful, don't flex that center section just yet, we still need to add a horn plate on the belly side only in order to reinforce it, then we will wrap the entire handle area with sinew. In order to make your belly handle piece, you need a flat piece of scrap horn. Tom uses curved scrap from the side of the horn we cut at the beginning, heats it by holding it it 2-3" over the electric stove while constantly flipping it, and then clamps it between two 2x6's in a vice until its flattened completely out. I did not witness this part, he already had a few done this way. Cut your handle piece roughly to the dimensions of the bow (approx 1.5"x 4.25") to be safe.
Then the work begins. You have to work down the now glued-up handle section of your horn bow in a concave manner naturally following the contour of the belly. This one is hard for me to explain, so hopefully my pics can. Then you make the horn plate convex to mate up to it. Hold it up to a window or something light behind it to check the gap, remember only a little light or space can remain(like a millimeter or less). Then thin down the ends of the plate so that it will flex a bit when you clamp them down with your small clamps, allowing them to mate up nicely to the belly surface of the bow.
Note-the second pic still needs signifigantly more material removed. The 3rd and 4th pics are a different bow.
NorthHeart:
Making the horn plate for the belly side of the handle. In the 3rd pic this is the rough version which must be thinned substantially more, especially at the ends so it can flex a bit when clamped. It will end up 1/8" thick or so, and obviously a bit thicker at the middle. Overlap the ends of the splice a little bit as pictured.
NorthHeart:
So now you've got the belly side of the limb splice worked down and ready to accept the horn plate. For this step, Tom puts the handle plate on the same way as he spliced the limbs together. Dip it in the hide glue and then rub the spliced horn belly with glue...again all messy like. Then use your 3 clamps and repeat what you did before, applying light pressure to just barely squeeze the glue out. Let it set for a day. Its freezing outside, so we set ours indoors by the stove, not too close just so its warm. 3 bows side by side, ready for the next step.
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