First ash bow, need advice on limb thickness

[George Elkstalker]

I'm building an ash bow to the dimensions of the Meare Heath ancient bow.  It is 68" with a narrow, deep, non-bending handle.  Limbs are 1 3/4" wide half-way tapering to 3/4" at nocks.  Limb thickness is already at around 3/8"  all the way down.  With one coat of sinew backing it pulls very hard just to get it to 5" brace height.  
     Any ideas on just how thin it can be safely made?  I'd like about 50# at 28".  PLEASE HELP THIS NEWBIE

[Pat B]

You can go as thin as it takes to get it to 50#. I never measure thickness on a selfbow but remove wood until I get it to bend well and to get my desired weight. I'm not trying to be flip about this! You can also reduce the width to help loose weight.
  With the sinew backing your bow should be strong enough. I assume you used sinew as  protection for your bow. One layer will do fine for that. Generally for a sinew backed bow the shorter the better. The sinew and hide glue weigh more than the wood and at the length you've chosen it can be a detriment to preformance but as protection it will be fine.
   After you are sure everything is lining up OK at brace, you can reduce your limb tips to 3/8" and this also will help with less hand shock and greater arrow speed.
   Welcome to the fun world of wood bow making!!!    Pat

[George Elkstalker]

Thanks Pat, all help appreciated.  Did you mean reduce to 3/8 width or thickness or both?  Also, this thing had a nice natural reflex but after just pulling it to about brace height I was disappointed to see it try to follow the string.  Any ideas?  Once again, thanks!

[Pat B]

George. I was talking about 3/8" wide tips. I usually leave my tips thick(1/2" or so) so I can reduce the width and this will help reduce the physical weight without loosing the strength. I like the tips to be stiff  anyway.
   I don't use ash much because I am too hard on it and I always have excessive set with ash. Others make beautiful bows with ash, just not me.

[Roy Steele]

I agree theres no set thickess ehen it comes to wood bows all staves are different.And like PAT said your tips are way to wide.As always PATs right on.

[canid song]

what kind of ash are you working with?

i'd also like to ask how much exercise you've given the limbs in the course of tillering to brace.

the initial give can take a while to break in in the course of tillering, and if you move too fast, it can still be pretty stiff, and easy to brace too early.

if you just remove wood until the weight comes down to reasonable without enough exercise, you may end up having to brace higher.

i've been working with a lot of american white ash lately, and i have to say i love the stuff.

[George Elkstalker]

I haven't bent it very often or very far.  I just finished taking a little more off each limb.  With the long tillering string it still tillered great.  I put a shorter string on it more like the actual string size and put it on the tiller board and the tiller was way off. Is that good, bad, uncommon or what?  I got frustrated so I quit.  I hate not knowing what I'm doing.  By the way, I think it is white ash. It came from my property in western VA.

[Pat B]

A long string is good for only a short distance; 6" to 8". Beyond that point the string angle prevents accurate limb bend and weight estimation.IMO  After that, a low brace height of about 4" will tell you if your limbs bend evenly and together and how the string tracks from tip to tip.
  You can go back on the tree and get an accurate limb bend readings without stressing the bow like I believe a tiller stick does out, beyond a few inches. Also, after each wood removal I like to exercise the limb so the wood removal registers as soon as possible. When I first start the exercising I may only move the limb tips by 6" or so. You never want to pull beyond your target weight so as you tiller you can pull it a bit farther .

[George Elkstalker]

Thanks Pat.  I've been amazed at how little wood removal it takes to make a big difference  in the bend. Even when frustrated, this stuff is a lot of fun.  Can't wait to shoot this thing.