I built a take-down longbow from binghams. It has a bubinga riser and the limbs are maple with black fiberglass. It turned out nice and has been shot probably 500-750 times with no problems. It turned out about 35-40 lbs. I noticed that the limb glass is splitting where it attaches to the riser, about 4 inches long, between the limb mounting holes exactley the same on both limbs. What could be causing this?
You might be tightening the limb bolts too tight.
Sometimes if the wedges and lams can get a bit of moisture,it will swell em and split stuff too. Did you finish the inside of the limb bolt holes?
What Pat said also!
I used a spray finish, so maybe the holes did not get enough finish in them.