My horn bow build-a-long

[DC]

Glued the second  horn strip this morning. It was little more stressful than the first. The pressure strip added to my clumsiness and I got the grooves misaligned. The second time I did the first fit with a couple of clamps without the pressure strip to make sure the grooves hooked up. Then I clamped on the pressure strip on removing the first clamps as I went by. It started to gel as I was double checking all the clamps. Now it's wait for another month. Adam says I can fit the celik while it's drying. Can I do any other portion of the shaping?

[bownarra]

The trick is to wrap the horn onto the limb with thin, like a single strand of bowstring thin, cord. Use quick clamps initially to hold it in place, then wrap with the thin cord, remove quick clamps, fit proper clamps.
No its best to leave it for that long for the collagen bonds to form properly. I normally strip the sinew now. Go as fine as you dare and prepare 100 grammes.

[DC]

Thanks for the cord tip.

268 grams of elk leg sinew almost ready to go. Well, some of the 268 is bag.

[DC]

Now I wait another month

[Deerhunter21]

ugh the anticipation almost killed me the last time! well ill work on my hackberry bow if we have to wait.

[DC]

And this is one of the easy waits. Something like 6 months to a year for the sinew to dry.

[bownarra]

Are you going to wait 6 months on the first bow though??
You only need to leave it 2 months to be dry enough to tiller(if sinew is put on it thick layers). It probably isn't worth waiting that long on the first bow as it is likely to have 'issues'.
If you put your sinew on in 1mm thick layers 2 weeks drying time between layers is plenty. The very long drying times are only really for the sinew down the edges of the limbs. It can be 5mm thick there. Or for the very best performers once you have your methods totally down and you know nothing is going to go wrong during tillering.

[DC]

That's good news. Thanks

[DC]

The 'best' modern way is to get a router cutter made with 2mm equilateral triangles, make a sled for your horn and one for the core...... = perfection but not exactly traditional!

$275 to make one, too rich for my blood.

[DC]

OK back on my head. I can start shaping. I ground the excess horn off the edges so the bow will sit flat on a flat surface. I got a chip but it's where the horn will be tapering out to nothing. Horn can be brittle if you hit it the wrong way with a rasp. Then I figured where the centreline will be, double checked it and marked it all around with a compass. I couldn't see the pencil line so I covered the horn with masking tape and remarked it. I was pleased when the centreline was in the same spot . Then I laid out the width according to the measurements in "The Book". It looks very narrow.
Question for Bownarra In The Book he suggests making the kasan 2-3 mm wider for stability. Why just the kasan, wouldn't making the whole limb wider help the stability even more? It would mean making the limb thinner to maintain the DW I guess but isn't that doable?

[DC]

More

[Deerhunter21]

YES!! were back!

[bownarra]

I like the compass method
You could increase the width of the sal as well but it isn't really necessary as the extra stability is needed around the kasan eye. As it is the place with a bunch of reflex it is the 'problem area'. Remember the 100# plus bows aren't wider than around 30 - 33mm in the sal. Increasing width and decreasing thickness in the sal will also affect the return speed of the limbs. I presume you are making a lower weight bow? I just finished tillering a bow that is around 40#@28 and it is thin! The thinner these bows become in the sal the more finicky they can be.

[DC]

So instead off tapering as much in the sal I should keep the width further into the eye a bit and then have more taper in the kasan. I'll do that for now. I can always taper more. Yeah, I'm planning on about 45#@28. That's about all I can pull.

[bownarra]

Yes but keep the extra width for the full length of the kasan go back to standard width at the 'step' into the tip. I would aim for about 24 mm width at the end of the kasan and then reduce width to 11mm, thickness 17mm at the tip.
You can then reduce width of the kasan once the bow is tillered and stable.
One thing that is easy to get wrong is leaving the core too thick at the kasan eye. You want it to open almost fully here at full draw but if you leave the wood even a shade too thick it won't open much during the draw, this will increase set in the sals a lot and more importantly make stability more problematic than it needs to be.