lamination questions

[The Gopher]

Am I correct in stating that the reason thin laminations are used in fiberglass bows is that it is much easier to make curvy shapes with thin laminations than with one thick one, or do several thin laminations make a bow more stable than one? the reason i am asking is i am starting to get things together for a straight limbed hill style bow. couldn't i use one thick lamination on the back, where there are no curves? the belly lamination would still be a "normal" thickness since it has to make the curve on the fades. I was planning on making my own lams. my though process tells me it would be fine, but i don't know much about this stuff. what do you think?

[Stephen Graf]

Using multiple laminations makes for a stronger, more durable bow.  Generally it will also make it smoother to draw and faster to shoot.  In the case of a bow with reflex/deflex, you are right that thinner lams allows for an easier layup.  But for your straight bow, the advantage is that defects in the wood are limited to each lam and thus multiple lams "cancel out" any defect that would eventually cause the bow to fail.  It also assures that the tiller will be better because the limbs are made more homogenious my using multiple lams.  Using just 2 lams in the core is a great improvement.  If you make your own lams, just remember that a few thousands of variation between top and bottom limbs will affect the tiller...  Good Luck!  My best advice is, after planning as best you can, just do it.  Once you start things will become clear.  And, if it doesn't work out perfectly, which it wont, you have a natural excuse to make another!

[Apex Predator]

I generally use four lams between the glass on my straight bows.  I keep the core lams much thicker than the outer lams.  That way I can use heavy dense woods that are pretty on the outside without too much weight.  On a typical 50# longbow 66" long I will use two .110 action boo core lams and two .55 outer lams.  Yes, the thinner lam is easier to layup on the fades than a thicker one.  I have just the one belly lam over the fades, plus the glass.  Works well for me.