Fiberglass to wood ratio

[Tunames]

Is there a guideline for glass to wood ratio? When would you use .40 glass instead of .50? What about wood to wood ratios. For a given stack size is it ok to use three or four equal sized lams? Just thinking out loud....

[kennym]

I asked this awhile back,most use 20-25% glass in the layup. I don't think thickness on the lams matters much as long as you get your total thickness. Of course more lams will be more stable just for the laminated effect.

[Tunames]

Thanks Kenny

[Todd Eric Tichenor]

I use .50 for durability. I build take downs, one
piece recurves and longbows. Never had a bow failure
with .40, but if you ding it, it will splinter out
easier than .50. I shoot all my bows through a
chronograph and don't have any fps diff due to using
.40 or .50 glass. Speed is more a factor of bow design. Thicker glass is tough to tear up.
Todd

[KVTA TANK]

Hay Todd if you want a set of 65# limbs how many lams would you use with .50 glass..  :confused:

[defiant]

Too many factors to consider like riser lenght,type of wood used for lams,tapers,parallel,overall lenght of bow,and bow form to hit the mark exact.I keep a log of all bows made and use it for a referance and go from there.Your best bet is to call John at old masters or bingham for info on the type of bow you plan to make and go from there.

[Asafan]

In my bows glass makes only 10-15 % of thickness of a stack, but it does not influence speed. Above to directly layer lams and hardly set there is more than requirement, but weight of a shoulder is less.

[manfromthepast]

It makes a big difference whether you are talking recurve or longbow and which style of longbow as well as length.  The recurves I have looked over as well as made have a glass (both layers together) to total limb thickness (including glass) ratio closer to 25%to 30% at the fades.  Longbows, especially deeper cored "Hill" style bows will have a lower ratio of glass to total limb thickness in the 20% range.  I have never made reflex/deflex longbows or flatbows but it would make sense that their ratio would be somewhere in between the recurve and "Hill" style longbow.

[Bob Sarrels]

In pretty much all the bows I build I use 50 on the back and 40 on the belly.  If I am looking for a 50lb 62" longbow I am right at 355 at the butt. That will change appx. 1 lb up or down for every pos or neg .003 in.  It is far less on a recurve.