I agree, it is very dangerous to glue a prop back together. Seriously, someone could be injured or even killed. Imagine the amount force on that prop blade WHEN it lets lose. Please reconsider reusing those props. Props are really one of the least of the expenses of RC. Why not cut a corner somewhere else. For example instead of buying 10% fuel, buy a gallon of 5% and a new prop, the price will be about the same and everyone will fly safer!!!