Tillering before sinew back? What about violations?

[poplar600]

In the process of taking down my 56 inch yew stave to a rectangle of 2 inches wide and 1 inch deep, then gonna leave it for a week to ensure no twist develops. Will prepare tendons into sinew during that time.

When the bow is all ready for tillering, I imagine there will be quite a few ring/knot violations and I'm going to get the back perfectly flat for the sinew, though I understand you need to tiller and then add sinew? Wont it be risky tillering a bow with a violated back? Understood the sinew was to protect the back and add performance?

Sorry for the noob questions, I only have experience in self bows.

[poplar600]

I understand there is no need to chase a ring and leave wood around knots when making a sinew backed bow?

[wizardgoat]

I sinew after the bow is bending enough to be braced. So you can see if you need any heat corrections, and your limbs will be thin enough to hopefully pull the bow into some reflex.
If your knots are solid leave them or put some thin super glue in. If they are punky dig them out and fill. Your posting a lot of questions on this particular stave.
Please post pics and you'll get better advice

[poplar600]

Sorry I just have no idea when it comes to sinew backed bows. Learning as I go along. Reading the chapter on Native Indian bows in TBB1, and I've settled on design and dimensions. I have a plan in my mind, I'm just unsure on the correct time to back with sinew.

I tried posting a bunch of pics, but I can't make them smaller for some reason?

Right now I'm getting rid of all the sap with a draw knife.

[JoJoDapyro]

Just my 2 cents. Slow down and take advice when it comes. You need to resize your photos smaller. If you are posting on your phone, look for a photo resizing app, if on your computer, there are several programs that will also do it.

[poplar600]

Low rpi, but seasoned 5 years. Feels really crisp under the draw knife. Shame about the thick sap and low rpi.

Getting rid of all the sap and making a California inspired flatbow. Again will be my first sinew backed bow, but have experience with working with longer yew self bows.

Just getting a straight rectangle out of it with little to no sapwood on the back.

[wizardgoat]

Removing all the sapwood isn't totally necessary, it's more of a preference. Just make sure you will have heartwood on the belly.  Slightly round your back, most original west coast bows have a slight lenticular or lemon cross section. Wide bows get very flat, and easy to hinge out if you do t have much experience. I'd recommend going no wider than 1.5".
If your wood is seasoned 5 years you can go a head and rough out the whole bow and get it bending.  Post pics of your progress. Learn how to use the search engine, there's been many many many builds on here similar to yours.

[bradsmith2010]

i would work the back just like a self bow,, then put the sinew over that,,,, there is no need to tiller before applying the sinew,,, you can if you like,, but you are taking a risk of breaking the bow,,

[poplar600]

I'm getting rid of the sap for aesthetic reasons, though I don't mind a little.

I have my wide rectangle all marked up and I'm taking it down with draw knife and various rasps. I'm not going for a full blown California flatbow, just using the style.

The wood is so well seasoned it's paining me to just hog through it all. Wish I could add another 20 inches of length 

Anyway I'll take the bow from the stave and sinew it up, then leave it for a few months.

[wizardgoat]

looks like a sawn stave, be careful with your draw knife

[PEARL DRUMS]

I was given a super old set of yew billets with no sapwood on them and micro rings that were all blended together. Here is how I went about it. I Z spliced them, profiled the bow on my saw, worked the limbs thickness down enough to get a half azz floor tiller accomplished without blowing it up, then heat shaped it, added sinew, then finished tillering. Its now a killer 60" bow.

If you don't at least floor tiller it close prior to adding sinew each limb will take on a different amount of reflex based on that limbs flexibility when the sinew was added. I would suggest at least getting them bending on the floor evenly prior to adding sinew.

[poplar600]

It's sawn, but the grain as been roughly followed. Once I start getting to near finished dimensions, It'll be all rasps and then files.

[poplar600]

It's sawn, but the grain as been roughly followed. Once I start getting to near finished dimensions, It'll be all rasps and then files.

I'll get it bending in the vice then and get some even bend.

[bradsmith2010]

i agree with Pearl on getting it to floor tiller,,

[poplar600]

My process of floor tillering is putting the bow in the vice and pulling on the limbs, and going by look and feel.

I'll post photo's as it comes a long. I'd like a rough blank by the end of this week.