Thinking about sinew

[bjrogg]

I always use back tendons. So much easier, but, still a ton of work. That stuff is looking really good BJR.

I always use the back sinew for my other projects to Drums. I remember talk with Matt W and he said he preferred the leg sinew. I think I can see why now. It is definitely easier to get the back sinew, but I like the evenness of this leg sinew and the length is pretty decent.

Bjrogg

[bjrogg]

cant wait to see the finished product! 

Me too Russell, but don’t wait up.lol

I’m going to have to gather some other stuff too and it’s going to be a problem finding the time to do this job, but I’m going to give it a try.

Bjrogg

[bradsmith2010]

you can do it a little at a time,,

[superdav95]

Thanks Dave I was hoping you would give some advice.

I did wash the tendons in soapy dawn dish water when I first harvested it. That really helps with removing some of the sheath that surrounds it and a lot of the fat.

It does still have a little

If I understand correctly next I should continue separating it and then wash with dawn?  I’m thinking I will have to comb it out then, get it straight and let it dry again. Or should I just wait until I’m ready to apply it to wash it again?

Hoping to avoid learning things the hard way.

Bjrogg

BJ.  I would let it dry well now after you gave it initial wash then pound it good to loosen up your fibers and separate by hand and use your combs or wire brush to get it to hair like strands.  Then I would weight it in matching bundles for each limb by weight and same length.  Wash it again after soaking it in warm water in your measured bundles in separate tubs.  In the mean time you would have sized your bow back surface really well to prep for sinew and let dry.  Sizing is many coats of very thin glue 5%.  I keep my bundles in the little separate tubs with water till ready to put down on my limbs.  I squeeze out little of excess water place on hard smooth clean surface like a counter top and comb it while wet to get fibers aligned and somewhat flat.  I work on one limb at a time so that my glue doesn’t gel too quick on me before I get my bundle on the bow.  Only but 30% glue layer on one limb at a time as you want to glue to be pre gel state when you apply your bundle to that limb.   I take the bundle in hand and dunk the bundle into the 30% glue kept hot in double boiler.  I found doing half at a time is less messy.  I use a large wide mouth mason jar for my glue and after dunking half of my bundle I use my finger to lightly press the bundle against the inner wall of the jar to squeeze out excess glue.  Repeat for remaining half of your bundle the lay it down. Move fairly quickly but not panicking. Have a little warm water nearby to wet your fingers to smooth out your bundle. I’ll sometimes use my standard plastic comb to keep the fibers aligned after laying bundle.  Repast for other side.  I place a smaller shorter bundle to overlap the longer bundles at the handle.  Save your longer sinew bundles for final layer if doing multiple layers.  I find doing 2-3 thinner layers allowing to dry hood in between layers goes the best.  About a week or two this time of year should do it for each layer.  My second layer is already pretty much dried after a few days.  It’s good to wait for a week or two between for good measure though.  I’ll find the thickness to dry time formulas rule of thumb and post it here too.  I’ve got it here somewhere. This is basically from Adam’s book on ottoman bows. 

[superdav95]

Here’s the small section from Adam’s book detailing dry times and thicknesses…
“As the sinew and glue dry, the
moisture travels through the layer
by diffusion. For a bow with one
layer of sinew about 1mm thick.
the time of drying is commonly 1
to 2 weeks, depending on ambi-
ent humidity. The time of mois
ture diffusion through the layer
increases with a square of thick-
ness. It means, if 1mm thickness
requires a minimum of 1 week,
then 2mm require 2 squared
equals 4 weeks. Then 3mm
requires 9 weeks. The bow's
sinew is actually 4 or even 5mm
in some places, for example the
limb sides and possibly the grip.
4mm will dry in 16 weeks and
5mm in 25 weeks - six months,”

[bjrogg]

Thanks Dave.

I really appreciate your response. I know I have a lot to learn here. I have never used hide glue so just figuring that out I’m sure will be a learning experience. Speaking of hide glue I still need to get some.

I did wash the sinew when I harvested it a couple years ago. It’s very dry now. I think my next step will be more separating and combing to get it hair like. Also weight and bundling.

In the meantime trying to get some hide glue. And set up some type of double heater.

Gotta few other things I have to do this weekend. I will magically transform into a Jolly St. Nick several times in the next ten days. Everyone knows how busy Santa gets this time of year

Thanks again for the support I’m thinking Santa will put you on the nice list.

Bjrogg

[superdav95]

Thanks Dave.

I really appreciate your response. I know I have a lot to learn here. I have never used hide glue so just figuring that out I’m sure will be a learning experience. Speaking of hide glue I still need to get some.

I did wash the sinew when I harvested it a couple years ago. It’s very dry now. I think my next step will be more separating and combing to get it hair like. Also weight and bundling.

In the meantime trying to get some hide glue. And set up some type of double heater.

Gotta few other things I have to do this weekend. I will magically transform into a Jolly St. Nick several times in the next ten days. Everyone knows how busy Santa gets this time of year

Thanks again for the support I’m thinking Santa will put you on the nice list.

Bjrogg

No problem at all. Glad to help. As for hide glue you could make your own but it is very time consuming I found. It’s novelty wore off pretty quick.  I just buy mine from 3 rivers archery.  It’s the granular stuff and it holds very well.  The mix instruction say 1:1 by volume that come with the glue.  If buying from another place just stick with 1:1 ratio by volume for mix or basically all I do is put enough granular glue in my mason jar and put just enough water to cover the granular.  Works every time.  The other measure that works good too is by weight. I general use 2:3 ratio of dried glue to water by weight. This is what I stick with for horn glue ups.  For sinew I go a little lighter 1:3 by volume.  Some may say this is too light but I like it for sinew.     Not all my glue in in small granular.  My sturgeon glue is in bigger squares so I use the weight ratio instead.  Still works good.  Basically looking for a consistency of a med to light syrup thickness when hot.  As you let it sit in double boiler it will get thicker as it looses moisture. Just tiny bit of water to get your consistency back to where you want.  For my sizing ratio do this by volume again to get your 5% for at least first few coats.  Doing the math it would be 1:20.  This may seem ridiculously thin but you want it basically like water to start with for sizing.  Then go to 1:10 ratio for rest of sizing coats.  Heat up with radiant heat your limbs to really soak in the thin glue for those first few coats.      As you get used to the glue and mixing you’ll get a good eye for the Color and consistency you want for subsequent bows.  It’s not as mystical as it may appear.  Good luck with it.  Here’s my simple basic double boiler set up.  The last pic is my latest haul for back and leg sinew. 

[bjrogg]

Thank Dave very helpful information for someone like myself.

Santa definitely has you on his good list

Bjrogg

[Piddler]

Thanks from me as well Dave. Lots of good info. Gonna try one myself before long.
Piddler

[Selfbowman]

Interesting thread. Maybe y’all can convince me to try one. My problem is patients. I’m sure it will turn out way cool.

[superdav95]

I say go for it.  It’s got some work involved but the results are great when done right.  It’s like natures fibreglass.  There’s just something about the process that connects with me in some weird way. Can’t quite pin it down but I dig it!   

[bjrogg]

Was a busy weekend with birthday party and a magical transformation into JollySt Nick.

I didn’t have much time to process sinew but I experimented a little and hard coming up with something that looks as nice as yours Dave. I can see you have the process down to a T.



I say go for it to Arvin. You’ll probably still finish it before I finish up that bow from that stage you sent me.

Bjrogg

I was just looking at my bows and when I looked up I saw this in the mirror

[superdav95]

Hahaha.  That guy is everywhere!

[bjrogg]

I’ve been working on sinew when I get a chance. I think I made pretty good progress.

It seems like everyone said they used back sinew and and previously that’s what I have used whenever I used sinew

I’m kinda liking this leg tendons sinew now the further I get breaking it down.

The pieces are nearly the same length. Back sinew might have a few longer strands up the center but then shorter on the sides.

I haven’t actually uses these yet but I think I’m done breaking it down until I use it now?

I basically have it separated into a couple strands till about a half inch from one end. There I left it to hold bundles together. If I need it I can pull it off like a sticky note

I don’t know if my plan is a good one but I can adapt it if I need to

Bjrogg

[superdav95]

Looks like good stuff!