English Yew Self Bow- wobbly wood

[tomthumb]

So...

I've put a centre line down the back and belly and the stave has now picked up some new curves!

The *wobbles*, the ropey features in the stave are having quite a lot of influence over the shape of the bow, as you might be able to see from the sides. I could cut right through them, but the draw knife seems to be picking them up naturally...

[Del the cat]

Yup, go with the flow 
Beware if the drawknife starts taking you where you don't want to go or digging in, it's time to grab the rasp.
Lookin' good.
Del

[tomthumb]

The stave on the left is mine.. The stave on the right is my friends made from the sister piece of yew. As you can see, he's a fair bit further on than me.

This picture probably shows best just how wobbly the sap wood really is; it was worse hidden underneath the bark.

I've left mine fairly wide at the tips and have left some extra depth through the handle. I'm sure as sure some of you will notice the dangerous looking depth of my friends stave where the back undulates through the ropey part; Mine has similar features. I'll pass on your reservations 

Time maybe to start a bit'o'bending..

[Del the cat]

OUCH! 
... Yes ! Don't copy your friend, he has some horrendous thin spots, he hasn't got the belly following the curves of the back.
Run the stave between finger and thumb you should feel a V gentle taper with no sudden thick or thin spots.
Del

[AndiE]

Hi

It seem that your friend is good in building predetermined breaking points. 
You must follow the shape of the back, so if the back is concave or convex the belly must be the contrary and not flat.

Kind regards
Andi

[mikekeswick]

Now then, looking good so far on yours but your friends is toast - lots of weak spots....finger calipers and lots of use off!
Where are you? I live just near Darlington and could help you out with getting the first one shooting.

[Del the cat]

Mike,
"Finger Calipers"
I like that, I may have to borrow it
At least they don't get lost on the junk on the work bench
Del

[tomthumb]

Haha He knows only too well he's made a big mistake..

So I have been using my "finger callipers" to make sure I don't do the same. Again, the only complication with this is that the back isn't flat, so when doing this, on the belly, the resulting lines can be quite far apart on opposing sides. This is mostly through the ropey parts. Presumably this is going to make the bow a little snakey... Does that make sense? I'm not sure if it does :/

Thats very kind Mike. I live off towards Helmsely on the other side of the North York Moors. Not a million miles away!

[Del the cat]

It's all about compromise...
This post from my blog where I have exactly the same problem may help..
http://bowyersdiary.blogspot.co.uk/2013/11/dealing-with-dip.html
Del

[tomthumb]

Thanks Del. That is exactly the same issue.

So, here come the sighs... I've violated the grain on the back of the bow, where this sap takes tips and twists...

I know, I know, "dont take the bark off till late".. Unfortunately I'd had already done this. But! the belly is now largely following the back. I guess places where this is not the case will show themselves when it goes on the tiller.

[Del the cat]

Following a ring on the back is an aim rather than a commandment! You can see sometimes you jus thave to remove sapwood else you'll end up with no heart wood... like I said, all about compromise.
I have one bow that had a big dip where the sap suddenly went thick and I had to go down through 8 rings
It was either that or have no heartwood... the bow has only lasted 40 years so maybe the jury is still out
Del

[AndiE]

Hi

Has anyone ever had to build a yew bow with only 2-3 sapwood rings?
I think my actual stave will be a problem like that.

Kind regards
Andi

[tomthumb]

Hi Andi,

Most of the yew I have come across in the UK has too thicker sap wood as opposed to too thin.

In principle, it shouldn't be too much of an issue, however I can imagine it totally depends on the thickness of each sapwood ring and how you you make the bow.

I was just saying how Ive managed to violate the sap wood on mine... I wouldn't do that with yours!

The other option would be to back the bow with something. Its not something I have very much experience with, but I can imagine that helping if your sap looks a little thin/weak.

Lets see what the experts say!

[tomthumb]

EURGHHH!... I'm very tempted to not put the tillering pictures up... Its pretty ugly!

[Del the cat]

Hi

Has anyone ever had to build a yew bow with only 2-3 sapwood rings?
I think my actual stave will be a problem like that.

Kind regards
Andi

I did have one stave that have very thin sapwood about 1/8" thick it became a warbow which eventually broke after about a year of good use.
Del