I'm a paramotor pilot and from time to time need to repair the edge of a composite propeller. I already make repairements with poliester filling kits. But want to make it with the right material and
methodes. Don't imagine it like the propeller of an airplane. it's not dangerous to fly with it, because a paramotor flies with the wing. Motor and propeller helps it in vertical direction. I can fly and land 
safely even with a shutdown motor. Only thing what I have to care is the balance of the propeller not to damage my engine because of heavy thrilling and a comfortable flight naturally. What I am talking about is not big damages. But a few cms damage at the final edge which sometimes happens by touching the cage. A broken edge shortly. 

We would recommend you consult a specialist in composite propeller construction and repair because if the repair failed and it goes wrong, you could have a catastrophic accident.  If in any doubt, I would strongly suggest getting a professional to do the work or replace the propeller with a new one for peace of mind. 

That said, it may well be possible for it to be repaired depending on the level of damage to the blade itself.  Much like many composite repairs, you would get a better result using proper fibres and a strong resin rather than just a filler material as this would help restore some of the strength to the edge rather than just doing a cosmetic repair.  The exact nature of the repair would depend on the specific damage to the edge.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant