About sinew. Pic heavy

[superdav95]

Hey guys.  Here a composite bow I’m working on currently while waiting on others to dry and materials for others nearing completion.  It’s a bamboo horn sinew composite bow.  It’ll be a somewhat Scythian  style profile hopefully when done.  It’s about 58”ntn.  I stuck with slightly thicker bamboo core then the 1/3rd thickness on this one.  It’s more like 40%.  30% horn 30% sinew.  I did no pre tillering on this core as an experiment.  Also testing out more crowned core prior to sinew.  I did the 20tpi longitudinal grooves as I usually do but kept them shallow and clean.  I did lots of size coats with very thin glue. Basically water with a little glue. Probably at least 10-12 coats or more.  Just kept going till it was shiny when dry.  I’d say 5% glue.  I use a half and half mix of high strength hide glue and sturgeon bladder glue for sinew.  For the horn I use mostly sturgeon glue.  Longer gel time for horn glue up is nice. 

So far I’ve got 2 layers of sinew totaling 75-80grams.  I use horse leg wrap after a couple hours after laying sinew and gelled up good and firm.  I let this sit for 3-4 hours then wrap in opposite direction and then leave sit over night.  It’s got just the right amount of stretch and breath ability when using horse leg wrap.  I use a straight stick and couple clamps to keep my tips aligned.  I’ve had them dry and pull a bit wonky before.  I’ll keep in creasing the reflex a little more on this one but it’s close to where I want it now.  Couple of weeks for drying I imagine and will be ready for next stage.  I’ll likley wrap with some thin rawhide.  I suspect a peg board for this one will be needed. 

Thanks for looking.   Here’s some pics showing some of process in reverse order unfortunately.  Hopefully it’s helps someone out there. 

[superdav95]

The next day after removing wraps off of second layer. 

[superdav95]

The horse leg wrap put on after an hour or 2 of gel up after second layer. 

[superdav95]

Just after second layer

[superdav95]

Wraps on after first layer

[superdav95]

Just after first layer sinew

[superdav95]

The grooves.  Note the shiny appearance and shallow grooves.  This is the rind side of the bamboo. 

[superdav95]

Here’s the glue I used for sizing.  Apply with soft brush. Very thin about 5%. For laying sinew about 30%

[superdav95]

Here I decided to file down the node bumps for a smooth surface.  Normally I leave them and just round them a bit prior to grooving the back. 

[PEARL DRUMS]

Very nice and very descriptive. Might have to ask Pat if he can save this thread in the archives once you complete it.

[superdav95]

Thanks pearl drums.  I should’ve included more but I guess folks can ask for more details.  Here’s a few pics of my scraper I use and blades I use. 

[superdav95]

Figured I’d add this pic of close up of limb after wrap removed.   Very little wrap marks if any at all.  I find this stuff works really well. 

[bjrogg]

Looks really good Dave. Thanks for posting this.

Really good timing for me. I’ve been working on processing sinew when I get time.

Bjrogg

[PaSteve]

That sinew looks very clean. It's obvious you're very detail oriented. The board to keep the limbs aligned is a great idea. One of the great things about this site is I'm constantly learning. Thanks for posting this, Dave.

[Will B]

Great post Dave. That sinew looks really nice!  Look forward to following your progress.