0.050 glass vs 0.040 glass...

[green valley gobbler]

I apologize if this has been discussed before but a friend and I are getting into bow building, laminated recurves.  We are following the Binghams blueprints and are building a 68 inch bow, shooting for around 35-40lbs.  According to their thickness charts we should be shooting for a limb thickness of .251.  The glass I ordered is 0.050. Our tapered lam(0.002/inch) measures 0.090 on butt end so therefore our parallel will be 0.061.  My question is should we be using glass that measures closer to 0.040 for a bow of 35lbs?  Is the heavier 0.050 for use in heavier bows?  Is there an advantage to using the thinner 0.040, my research I've done shows many guys using the 0.040 glass.  Thanks in advance.  Also any advice on our limb set up I listed above would be greatly appreciated.

[TradBowyer]

i like to use thinner glass because its lighter than 050 which translates to faster speeds. Just remember if you go thinner glass, you need to make it up by adding to your wood stack. I use 040 for everything. Theres a ratio of glass to wood core that experienced guys use. basically anything under 60# gets 040...over #60 gets 050. If this is your first bow and using Binghams prints, go with their kit and get your first one under your belt. Binghams design is pretty much fool proof for getting a nice shooter. Once you get a couple down and more comfortable, you can start changing things up. just my suggestion

[KenH]

.050 vs .040 is mostly a matter of "taste".  I find the .040 or even .030 bends more easily into extreme curves.  

The important thing is to maintain the TOTAL stack thickness, as that is what will determine your draw weight.

[fujimo]

i cant say from experience,
 but what i have read on forums, when going with  a thinner glass, and even compensating with thicker lams in the stack- to create the same overall stack height- will still result in somewhat lighter weight bows.

[Crooked Stic]

Going for that weight you could probably use .030 and have less mass weight in your limb.