Tillering before applying sinew

[stuckinthemud]

How far do you get a bow bending before you apply sinew? 

[bradsmith2010]

I usually just put the sinew on when it is reflexed,, and dont bend it or tiller it,, before applying,,
I have tillered it out some and applied sinew,, i dont see a need to tiller it out before applying sinew,, but not sure really what the difference would be,,
the bow should be thin enough that the sinew can put the bow into more reflex,,

[Pat B]

I usually tiller about half way before adding the sinew. I don't know if it matters, it's just the way I do it.

[bassman211]

I have tillered bows completely,  and then sinewed them, but most of the time you still have to do a little more tillering after the sinew.

[Kidder]

Not to highjack the thread, but on a related note, how much draw weight should one expect to add to fully finished bow by sinew backing it? I ask because I’ve got a stave that is currently on track for a very light weight bow but I always intended to sinew back it.

[gutpile]

I draw 26.5 and I till to 20 before sinew.about 6 lbs shy of desired weight I like to get the bow bending well.. so when I add sinew it will pull fair amount of reflex. I also hang a 25 weight suspended in between two chairs .. this also helps hold a good amount of reflex ..  as for how much weight it can add depends on how much sinew you lay down too.. I run a full course then add a over lay on that covering the ends and then fill in any gaps for a partial third layer.. never scaled it but could be as much as 10 lbs of weight.. but after tillering it on out end up about 6 -7 lbs.  this is a guess since I never have scaled it.. gut

[Pat B]

Kidder, I think you can add about 10# but I'm not fond of adding sinew just to increase draw weight. I'd suggest starting a new bow and from what you've learned from this one make another one to achieve the draw weight you dsire. If you want to build a sinew backed bow then design your build to go that direction from the start.

[Bryce]

I usually tiller about half way before adding the sinew. I don't know if it matters, it's just the way I do it.

Same. But if I’m going for mad reflex like in a horn bow. 18”-20” pre tiller

[bownarra]

I go with a limber floor/vice tiller It is advisable not to 'tiller' very far you only need it to be thin enough to bend backwards evenly.
As for adding reflex to a sinew backed wood bow.
Get the blank bending evenly.
Size the back well eg. heat and apply thin 5% glue until you have the back glossy. Scrape the back as smooth as you can get it first to get the best bond.
Apply first layer of sinew.
Let the glue gel.
Now add the reflex by reverse bracing.
This addition of reflex just after the glue gels will 'compress' the sinew 'into' the now concave (along its length) limb.
If you do it this way you add plenty of reflex and eliminate the possibility of the sinew pulling off the concave sections as it dries/shrinks.
Every layer add some reflex.