Laminated longbow question

[Nathan Bowen]

How narrow can you make The tips and outer third of a deep cored hill style longbow? I would build this bow with glass back and belly. Also What about making the wood core thick enough that you could use the thinist glass available even when making a 60#@28" bow? Would there be any advantage to this? Would the bow limb be lighter in physical weight?
Thanks
Nathan

[Pat B]

Nathan, I have only built one(not successful) glass bow so take this advise with a grain of salt!
  Limb and tip weight(physical weight) will effect the recovery speed of your limbs and will effect the amount of hand shock or lack of it. With wood bows I prefer to keep limb tips thicker but narrow them as much as safely possible. That way I can reduce the physical weight without reducing the strength. Also your outer limbs are generally non-bending so are not stressed the way the working portions of the limbs are. Reducing the glass thickness there will help reduce the physical weight and the rigidity of that portion of the limb should make it a safe option...but you best wait to see what the glass bow guys have to say.

[Dick in Seattle]

I'm another with one fully successful bow behind me, plus a couple of recovery projects.   Couple of  things that might be of interest to you...

I've seen a couple of longbows built with 3/8" tips... that's narrow.  I'm currently finishing up a bow that has a tip dimension of .669... only problem is, that isn't only the tip dimension... that's the width of the whole bow... tip to tip including the riser!  This was a case of one edge of a layup not laminating, so I sliced off what I could save and made a bow.  Came out 17# and shoots incredibly well.  I shot an 80 target 3D day with it Sat. and did as well as I ever have.  Someone suggested that the narrowness got rid of a lot of mass and allowed the bow to recover exceptionally well for its draw weight.   I chrono'ed it at 111 fps... with 15.3 grain per pound arrows, finger released from a 25" draw.  I plan to do more experimenting with exceptionally narrow bows.  Oh, yeah... the stack on this bow is .333, or a relationship of core to width of almost exactly 3/1.

Re glass thickness.  No personal experience, but advice I received early on is that glass thinned than .040 tends to be easily scratched or marred, which can lead to breaking.   I'm using .040 exclusively and trying to build to light weights of 25 to 30 pounds.