Hold my hand when I sinew my first bow

[jameswoodmot]

Brilliant!

No worries, I’ll go back to 46 grams and I’ve got some processed ready to go for the next one. I have no reference for how much sinew will give how much extra draw or draw weight so I’ll start there and take my notes and then work from that for the next one. Mostly I just want more draw length for now.

I’ve got my bundles re sorted. I weighed them out this time which was much better and quicker, 2 grams per long bundle and 1 gram per short bundle.

My plan is to put a centre strip down with 1.5gram  bundles on the tips, the run a strip of short strands along both edges and then fill in the gaps with long bundles. Keeping it slightly heavier along the crown and around the middle. I’m going to do one heavy layer. The strands in the  bundles vary a fair bit in length which should make for a good overlap

[Robert Pougnier]

That's looking great!

I like your system for reverse bracing it. Looks like you glued some wood at the tips on the belly side to tack on some length with extra nocks  to have access to the whole bow when it's reverse braced? Good thinking. I will try that next time.

[jameswoodmot]

Robert, yeah that’s exactly what I did, I just super glued them on. I got a little crack under the nock the first time I braced it so I’m going to give them a bit of a sinew wrap under them, didn’t want the string in the way. Also got the double string wjth a pencil in it so I can just twist it up as it reflexes.

Well, I did it! Looks a right mess at the moment 😂

So I did one limb then the other, not sure if that was the best way, next time I think I will do a row at a time maybe. It felt like a lot of sinew to get on in one go, and I got a little confused about where to put some of the bundles as I didn’t keep them the same width as I spread them out. Over all I think the placement is fine. I had two short bundles left over which I couldn’t work out where to put so I broke them into smaller bits and I was able to use them to fill in a couple of little gaps

The glue was much stickier than I expected, I think it’s a thicker mix than I’ve seen people use before and I struggled to get it as hot as I wanted in the slow cooker, strange as it was getting too hot last night. I under up heating each bundle infront of the halogen heater after soaking in the glue.

It was more difficult that I thought rearranging the bundles once they were on the bow, the glue tacked up faster than I thought it would. Whether that is because of the temperature of it or just how it is I don’t know. I think a combination of both but I had the heater there to warm it up when I thought it needed it. I’ve got a layer of plastic wrap over it and then wrapped with with strips of T-shirt, the T-shirt didn’t behave very well so I’m going to the shop to get some bandages.

Once the bundles were down I’d say I had 30 seconds to a minute to move them around before they were pretty well where they were staying. I actually removed the first bundle after putting it down as it cooled way too quickly, I don’t think the bow or the glue were warm enough which is when I get the heater out.

[jameswoodmot]

It’s only been half an hour and I’ve already checked on it three times! I want to pull it!

Two weeks to cure?

[superdav95]

Looks great.  Now that you’ve done it each time you will find efficiency for the next one.  You’ll be happy you took the time to get organized too.  It makes for better consistency.  The heater is good but another idea that you may try is just a heat lamp or a couple of them aimed at you work.  I found this works good for me on bigger projects.  If you move swiftly though you don’t really need one.  The little bow I sinew last night I had two strip per side so it went quite quickly and just used water on my hand to smooth out and blend.  It’s hard to tell from the pics how thick your glue is but I do mine around 25-30%. 

[jameswoodmot]

Yes the actual putting the sinew on the bow doesn’t take long at all does it? Glad I took your advice
and got it all sorted and laid out and ready to go. The stainless brush worked well to clean the short stands out when it was wet.

I mixed the glue up to 25%, I think maybe the people I’ve seen do it on videos have just used thinner glue.

Tomorrow  when I take the wraps off can I fill in any gaps with more sinew? When I swapped the bandages there were a couple of small channels where bundles hadn’t met.
I guess warm the area, put down some glue and then put in more sinew than I think it needs so it can shrink down?

[superdav95]

Glad to help out.  I would hold off in filling in any gaps just yet.  I would wait at least a week and then see what it looks like before going to that.  You may find that it won’t matter and shrinkage is still occurring right now.  They may became insignificant as it dries further.  If it’s a twisted strand or strands causing a gap however it may get larger actually but deal with that also in about a week or more.  My method of dealing with little gaps is waiting a few days at least and then using hot thin glue use a porcelain mug and rub it down hard to compress the fibers and I think you find you won’t need to add any later.  I just use a little brush to coat the top layer sinew and then go at it with the smooth side of a mug or anything smooth that you can get a good grip on.  I’ll post a video on this too on my channel and put a link here.  It will not harm your sinew.  It will only need to be done once at like the 3-4 day dry point.  Do not try to do this when your sinew is not dry enough or at least looks mostly dried through the entire layer.  You will see no white remaining in your layer.  I say this because dry times vary wildly depending on where you live.  I’m in Alberta and it’s pretty dry here.  I plan to burnish mine at like day 3.   If after all this burnishing and compressing you still find you have unsightly voids you can decide after a week or so to fill those in.  Always add a little more to voids then you think as it does shrink obviously.  Take that into consideration.   I’ve also wrapped my patches depending on size.   This helps to match it up better with the rest. 

[jameswoodmot]

Humidity is about 65% here, much dryer in my house mind. I’ve got it in one of the cooler rooms.
Had a look this morning, missed a bit on the tip past the nock and a couple of bits on the edge that was away from me. Things to know next time!
The gap seems pretty big to me but I’ll see how it looks in a few days, I gave it a little squeeze and it’s quite squidgy under the top dry layer.


I was thinking about my process and why I got a bit mixed up on the second limb. I put two layers on the first limb, I should have done one across the whole bow and then put the second layer on over the middle section. I think I was concentrating on trying to get the first limb looking even and getting that one done when the glue was still tacky and I ended up feeling a bit rushed.
Then when I came to do the second limb it took a lot more thinking about where the bundles needed to go and the layout wasn’t as clear. Totally obvious where I went wrong in hindsight!still I don’t think it’s a problem, I might have shifted my distribution of sinew slightly towards the second limb, I’ll find its balance point and worst case I guess I’ll be able to sand it down a bit.

Should have some horse legs by the end of the week to strip the tendons from

[superdav95]

Looks great!  Give it a week or so and you’ll have a better idea what you need to do. 

[jameswoodmot]

I’ve just filled in a few bits on the edge. Not sure it’s necessary at all but i don’t think it’s really going to increase the drying time and it was annoying me. Several bits along the “back” side, the other side to which I was standing.

Got about 6” of reflex now.

I gave it a quick burnish at about day 3 (I was away day 4 to but having watched your video Dave I wasn’t aggressive enough. I was worried about getting it too wet and rucking up the top strands of sinew. It’s better but nothing like yours. I’ll leave it as is and remember for next time.

It looks like I think it should and I’m feeling confident about bending it.

I’m thinking wait for it to stop loosing weight then give it a few more days?

[superdav95]

I personally think you are fine now but that’s just me.  It’s a good rule of thumb though like you say to measure weight loss and then a few more days.  I keep my place here in Alberta around the 45-50% humidity.  The air outside is far more dry though.  I have a humidifier attached to the furnace which monitors this. So your level of humidity may change this a bit.  I started bending mine about week two.  I did mine right around when you did yours too.  I measured weight like you are doing and then watch it stabilize and even go back up which is a good sign you are there.  6” reflex is good.   It will mostly creep back to that after you tiller out the bow to what you want.  I’ve even seen this reflex increase a bit as it gets tillered.  This is because there is less resistance pulling back against the sinew and thus more reflex.  I did some pre bending on mine before laying on my snake skins.  I’ll start bending it again in a couple more days.  I just glued on my handle today so will give it a couple.   I posted a little about ratios on my little bow too but just to mention it here too I measure and premeasured my sinew and glue.  I mixed up a tiny bit more then I need in glue but not a lot.  I used most of it.  My weight of the bow prior to sinew was about 65grams less then after the sinew dried.  Some of this weight is glue.  So in essence 50grams sinew and about 15grams or so in glue.  After sinew dried my weight was 412grams.  Prior to sinew it was just over 347grams.  So about a 1/3 was glue give or take.  I then added my snake skins which added about 8-9grams bringing it to about 420.86grams.  It’s always good idea to monitor weight loss when it comes sinew.  Lots of factors that can change things so results and dry times can vary.   

[jameswoodmot]

Thanks again!

My fear of moisture is actually more about the wood than the sinew. It’s 85-95% humidity here and 50 degrees outside. Don’t know what the humidity is inside. It’s so hard to get white woods down to reasonably moisture content in the winter here. The only thing I can do is weight for them to stop loosing weight and hope that’s enough. Got a moisture meter on the way.


I didn’t think to weigh the bow before sinewing, I had the weight written down on the bow as I was drying it before bracing but forgot to reweigh it after.
The belly had gone from flat, the concave, to now pulling slightly convex in places now which is interesting to watch. The back isn’t going to become flat but but to me that’s more of an indication of the shrinkage than the reflex.

I’ve got one thick patch mid limb where I had too many overlaps, I think it’s going to be ok but I may file it down slightly, though as there are overlaps I don’t want to weaken that point

[superdav95]

Thanks again!

My fear of moisture is actually more about the wood than the sinew. It’s 85-95% humidity here and 50 degrees outside. Don’t know what the humidity is inside. It’s so hard to get white woods down to reasonably moisture content in the winter here. The only thing I can do is weight for them to stop loosing weight and hope that’s enough. Got a moisture meter on the way.


I didn’t think to weigh the bow before sinewing, I had the weight written down on the bow as I was drying it before bracing but forgot to reweigh it after.
The belly had gone from flat, the concave, to now pulling slightly convex in places now which is interesting to watch. The back isn’t going to become flat but but to me that’s more of an indication of the shrinkage than the reflex.

I’ve got one thick patch mid limb where I had too many overlaps, I think it’s going to be ok but I may file it down slightly, though as there are overlaps I don’t want to weaken that point

Ya that’s high humidity wow.  But don’t fret.  That’s the best environment for laying sinew for best adhesion.  It may take a little longer to dry but will be very solid.  As far as the clump in the middle I would just smooth it out and not file down completely just yet till you get bending it. You may find out later that you can safely file it off.   Keeping track of weights are important your first few bows to see patterns.  Once you get a feel for it you get the ratios right and other things.   The concaving of the belly would indicate drying and being pulled by the sinew.