Asiatic Composite Build-Along

[thimosabbv]

"I glued it on and there was a slight gap that was irregularly shaped, so I shoved a wedge of osage in there to fill the space."



Tom here I thought I was the only one doing stuff like that. LOL.  I figured everybody else got everything machine-perfect prior to glue.
"

[tom sawyer]

I should've, in fact this was the second piece I cut and it was still a little short.

I have seen xrays of artifact bows and they used little wedges of bone to fill in small gaps at the handle.  So we're just being authentic.

[tom sawyer]

I unclamped and cut off the overhangs, things looked OK until I noticed that about an inch on one end of the handle piece didn't glue properly.  I must not have gotten the boo core scored (with a hacksaw blade) very well at that end.  So I stuffed some 2-ton epoxy in there and reclamped.  I'm concerned about reverse-stringing this for sinewing, this piece may well pop off at that point.  I guess if it comes unglued I'll just reprep and reglue.  It should be fine when I actually use the bow since it will be pinched in between the horn strips.

[tom sawyer]

The epoxy didn't work worth a darn, the one side of the handle lam is still loose.  I tried to pop the whole thing off by bending in reverse, but the rest of the glue joint is holding well.  So I reverse-strung the bow a bit and proceeded with my sinewing job last night.

I had presorted my sinew into a couple of lengths, putting each bundle between the pages of a magazine (not PA, that would have ruined it).  I had also combed the last couple of inches of both ends of these bundles, with a dog flea comb (a larger tined one).  This got rid of a lot of tangles in the ends (where they are most prevalent).  Both these tasks really help you get a decent looking sinew job.

I made Knox gelatin hide glue, I used 3 packets in a cup of water but had to add another half cup to make it the consistency I wanted.  Too thick and it gets real sloppy.  Kept it on a cheap hot plate on low.  I didn't have to add any water, since the sinew was prewetted with water and a little of this carried over into the glue each time.  I sized the heck out of the back of the bow, I think this is important in getting a good bond.  I used to think it would be better to leave it kinda dry but everything i read says to coat everything in several coats of thin glue so it sinks in as much as possible, and I definitely see the logic in that.

I first prewet each bundle in water, squeegeeing it out repeatedly until it felt limp and you could see the strands separate and be parallel under the water.  If I felt lumps I would keep squeegeeing and dipping, that would get the tangles mostly undone.  Then I dipped the bundle in glue and squeegeed, did this a few times to get it soaked in good.  At this stage you could really see the strands nicely parallel when it was under the glue.  Like well-combed hair, only thicker stuff of course.

I did a final squeegee and this gave me a flat, reasonably uniform strip of sinew to lay on the bow.  I started down both edges and then laid a strip in the middle.  I smoothed things with my fingers, I wished I'd had a piece of antler like Hamm uses in TBB because at times the sinew would want tmo stick to my fingers a bit.  Smoothing is definitely something you can do too much of, because when you pet it one way you run into the next bundle and it might pull up the ends of those fibers and then you have a bit of a mess to contend with.  So I smoothed as best I could and went on.

I did one thick layer of around 3/16" wet, this will shrink down considerably of course.  I ran the sinew up onto the siyahs, and went over the handle with a thick layer as well.  I did not go over the sides, decided that might just add weight but no performance or safety.  And I didn't wrap any ends yet, I'll let this dry down some and then wrap the limb/handle areas as well as the limb/siyah areas (where the horn ends) to keep everything from pulling apart.  Might use sinew, but am considering thread and glue as an alternative.  That would look nice, be plenty strong and use less sinew.

Anyway, there are a couple of pics of the sinew job in all its wet/sticky/messy glory, at the link I have above.  Not much to see really.  The sinew isn't as brown as that one pic makes it look, that is just a lighting thing.  And disregard the mess on the workbench, I need to doze the whole shop again soon.

[OldBow]

Really neat! Maybe ready for Bow of the Month -Backed Bows for November?

[tom sawyer]

Hard telling, but that is probably a reasonable estimate.  My experience with sinew, is that it takes a few weeks to get reasonably dry and then it still changes for months afterwards.  You can shoot it in the interim, but I learned my lesson and don't try and chase a perfect tiller on sinewed bows because they look different every day regardless.  The good thing about them, is that they perfrom well regardless of what they look like on a given day.

I will need to wrap several areas with string or sinew, to keep things from delaminatiing.  I'm probably going to cover this bow in silk if it survives.  I only give it a 50/50 chance of becoming a bow.

Another thing I read on the ATARN site, is that it is possible to get sinew TOO dry.  It is supposedly more likely to fai if this happens.  I always tried to get mine bone dry through rapid drying, could explain some of my failures in the past.  I always just attributed it to bad prep of glueing surfaces.

[Rich Saffold]

Looking good Lennie! Its great fun watching you and Thimo dive into these, because I know I don't have the time yet to try one, but soon enough will.

[thimosabbv]

Looking good Tom.  I know exactly what you mean about trying to "unglue" stuff. I had to saw a handle off yesterday and that wasn't even epoxy.

By the way your workshop is starting to look like mine. 

[tom sawyer]

Rich its really not much of a stretch from doing a backed bow.  Just a belly lam that happens to be horn, and a sinew job.  The siyahs really aren't a big deal.  The "fun" part is yet to come, getting the bow lined up properly.  I'll make tepliks for that.

This one is practice before I do one the old fashioned way, with hide glue and following a more aggressive and authentic pattern.

Thimo our workshops have that "lived in" look eh?  My dog hung out with me last night, she chewed up six chunks of 2x4 and ate a big piece of leather while I was busy sinewing.  We both had a good time.

The sinew is drying slowly, the edges are clear but the center is still white.  No sign of cracks though, I'm not going to speed anything up with the drying box until the sinew is clear.  Then maybe I'll cook it awhile.

[tom sawyer]

Time for an update.  There are a few new pics on the photobucket site, I think they are the first three.  There's an unbraced side profile, and a couple of the bow being pulled with a long string.

The sinew is reasonably dry now.  I added another layer to the handle/fades and inner limb area, it seemed like the first layer was heavier at midlimb and I sure don't want to stress the handle area any more than necessary.  I got my handle spacer piece fixed as well, I ended up cutting the loose part off (1"), repreping the surfaces and then reglued it with a shim to take up the space from the kerf.  It seems to be good and solid now.  I cut some nocks into the siyahs, I am either going to reinforce those with horn or make my string with a little leather strip at the nocks.  Maybe both.  Also thinking about reinforcing the siyahs themselves, lashing something like bone plates on either side like the ancient bows had.  The walnut just kind of scares me, then again the whole bow scares me!

First I attempted to make tepeliks and tried to tie those to the bow's limbs.  It worked OK but I couldn't really get the limbs cinched down all the way with my rope loops.  I have to research how that is done, a little more thoroughly.  I bagged that for the moment, and used a long string to see if the thing was going to stay together when bent.  So far so good.  It is going to be one heavy beast though, I worry about it staying together becuase of that.  I did just a little scraping on the horn, with not much effect.  I think the bottom line is, my core was a little too thick at a good 1/4", and I'm going to have to live with the higher poundage.  I might try narrowing the limbs a bit, but the width gives them stability and I'm scared that narrowing will make them want to lean and that will be the end of the bow.

I'm also less than happy about the angle on the siyahs, I didn't make them real radical but I was hoping they would show about perpendicular at brace.  They seem to be bending a little past that though, hard to tell with a long string I guess.  I tried to string it using a nylon cord for a string, but the string stretched too much.  I'll have to try making a linen string tonight.  But I'm maybe going hunting after work, and there's Monday night football too.

[DCM]

That's a perty dog gone aggressive projek Lennie.  Looks like you got it by the short hairs too.  Darn thing bends good.  Need to stock up on greens afore the killin' frost comes, so you can draw the darn thing.  The grain pattern in that walnut has got me spooked boy.  Seems like you'd want the grain running along the lenght.  But then what do I know.

[tom sawyer]

The grain runs parallel in the joint area.  I thought that was most important.  The rest of it is stiff so my thought was that it would hold up.  The angle isn't that aggressive either.  But like I said, I'm contemplating bolstering the siyahs with thin side plates of some sort, lashed on with sinew.  Might have to get a rack of spare ribs just to get some sideplates.  Wonder if sauce will mess up sinew?  That'd be better for strength, high protein.

I think they normally heatbend the siyahs, or glue them together from pieces that have the grain running lengthwise, instead of just cutting them out.  Hey its a first attempt, I never figured it'd get this far.  I keep waiting for it to blow, gotta find the ol' football helmet.

Now I gotta get started on a Fu Manchu to get in the spirit of things.

[Roger]

Dang Lennie...that looks great so far! Looks like a fun one to do. I've got some real nice Mulberry...might just have to give one of those a go soon.
  Great job bud!  hope the horn holds for ya.

Sparky

[tom sawyer]

Thanks Sparky.  They used mulberry a lot for siyahs.  I'm sure it would make a good core as well, being fairly light.

Heres the update for this evening.  Its mostly good news.

I managed to make a string that didn't break when I tried to string this bow.  It is 14 strands of dacron, simply doubled over on each end and tied with an overhand knot to form the loops.  I strung the bow using a stringer, that seemed to work pretty well.  I needed the leverage, this thing is a bit of a beast.

I have posted a few more pics in the link above, one is the bow braced, one is the bow's side profile just after unstringing, and one is the bow partially drawn on a tiller stick.  I don't have a tiller tree rigged up and nobody else was home to photograph as I pulled the bow.

As you can see I have one limb that is somewhat stronger than the other.  I am seeking suggestions on how to even these up.  I've scraped a bit on the horn on the stiff limb.  I may also add another thin layer of sinew on the weaker limb.  Although this remedy will increase the poundage a bit I suppose, not really what I am wanting.    You can see in the just-unstrung pic, that the weaker limb is showing a bit more set than the strong limb.  It seems fairly even, which is a good sign.  I was worried that more of it was showing up on the outer end of the horn, where I butted a piece of wood to it to bolster the inner part of the siyah.

I measured the poundage on this bow with my bow scale.  I managed to pull it all the way to 28" (back of handle) and measured close to 80lb.  This was with the scale hanging from a nail, and me pulling down on the handle with all my might/weight.  I shot a few arrows out of it but I can't pull it to full draw.  Shot very strong and no hand shock but that is expected when pulling a bow only 20" or so.  Hey Thimo, road trip on over here and pull this sucker to full draw will ya?

I did see a few small cracks in one area of horn on the stronger limb.  It is in the smaller of the two pieces spliced along that limb.  It doesn't look very bad but I will keep and eye on it.  The cracks run parallel to the limb, not across, so it doesn't look like compression fracture.  Might just be the horn drying or something, that is the piece of horn from the outer third of the length and some of it was solid.

The weaker of the two limbs, needs to be wrapped out by the end of the horn.  I got the piece of belly wood just outside the horn, just a little thin on that side.  I want to shore it up, although I need to decide about adding sinew to the back before I do my wrap.

If you have read all of this boring narrative, congratulations you are officially bored stiff.

[Roger]

Lennie,
 I've heard about guys scraping the horn to reduce weight. I guess you could always reduce limb width if ya have it to give. Have you sanded your sinew in prep for the leather covering. If your going to do that maybe you could give that a try as well. Maybe a little more sanding on the stronger limb. I am watching your progress with intrest.

Sparky