sinew backing, methods

dave_t_aber

New member
hello,
im on my fourth sinew backed bow the moment, its a lemonwood flatbow, with some static recurve tips of about 3 inches long, made out of elm, to improve the string angle. The bow is about 5ft 6inches, nearly 6 with the recurve tips, and 2 inches wide at the widest point.

I am trying a different method this time, instead of putting the sinew onto the flat back of the bow, I have meticulously scraped grooves about 3mm deep, 3mm wide, about the size of this 'V', into the back of the bow, into which I have placed a foundation layer of sinew, which fills these grooves. I am doing this, to allow the sinew to grip the bow wood better, as there is more surface area exposed for the glue to adhere to.

I am also using the warm hide glue method, but this time the glue has not gone above the temperature of blood, more like 30c maximum, whereas before I have accidently let the glue get to temperatures of 50c or so, im thinking keeping the temp low will keep the glue quality high, as the proteins in the glue will essentially remain intact.

I am using the grooving method mainly to practice, as I recently made a horn composite bow, with a massive recurve, and the sinew parted company with the bow when it was tested. On this bow I didnt use any grooving method.

I want to, in the near future, make a plains indian style horn bow, with no siyahs, and I am going to use a grooving method on this too.

Anyone got any good ideas for making sinew backing even more reliable/efficient.

Also, if you need sinew, google Highland Horn, they are a good source of good sinew, and do a good service.

Dave
 

^HUN^

New member
Grooving on both back and belly for sinew and horn gluing was a regular practice with Turkish composite bowyers.
Remember to size the limb with ever thickening coats of glue before the final job.
 
D

Deleted member 7654

Guest
Kudos for having the patience...
I'm hopefully going to graduate to the horn/sinew thing eventually, but I'm doing a fibreglass/maple lamination version first as I have the material lying about...all good experience.
Have you made up a special grooving scraper or special tool?
I cut a nice bit of curved grain Ash from a forked branch of a fallen tree for the siyahs :) .
BTW. I think the main problem on my smashed sinew bow was insufficient thickness.
I found a nice site t'other day with photos of cross sections from a Chinese bow...dunno if you have seen it? If not I can post a link...it shows some defects in the construction, a crack in the bamboo core, and probable overdrying as the core has shrunk at the handle. The cross-sections where the siyahs splice in are very edifying.
Del
 

dave_t_aber

New member
yes, I have a very expensive patented grooving tool, only to be used with a licence. nah, I just used a coarse cut wood saw, run it sideways down the bow, slowly.

yes, even a maple/fibreglass bow is good practice for working out how best to construct your horn bow.

Atarn.net, or some similar name, its a very very good site specialising in horn bows, seen some amazing bows there. google atarn if you cant find it.

Cheers
Dave
 
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