I would do like Kirk suggests, but add a little heat to the limb to enhance the wicking effect. I would also use some thin epoxy rather than CA, but thats a personal preference because I don't like CA glue for anything other than chemically welding certain plastics and rubbers.
I agree with the heat when using thin epoxy, but not with thin CA. The CA is very hot stuff. Now I have used a heat gun after I’ve let the CA wick into the crack to accelerate the tying time, but not before.
It depends a lot on how big of crack you are filling. Bigger cracks or splits due to checking in riser blocks, you’ll have better luck with warm thin epoxy. I’ve heated it in the microwave for a few seconds before pouring it into larger cracks with good success……
I’ll bet that the huntsman epoxy would work well on filling cracks. It’s pretty thin stuff. EA-40 is too thick by itself without heating it up. Kirk
But…. With micro cracks in glass the CA works excellent….