Quick advice needed - enlarging a long blind hole

One way to stiffen the mast is to laminate uni carbon over it. This allows to increase stiffness incrementally until it is acceptable.

 

Alright guys, thank you all for the advice, this topic has veered quite a lot from the initial, and we kind of started going in circles, so I won't bore you too much. With your help and with help from some other forums I was able to work out the equations I was after to calculate wood+carbon mast stiffness, and I am throwing together an Excel spreadsheet to make it accessible for everyone. Not sure what is the best place to post it on this forum so everyone can find it, is there some sort of "goodies" corner that I haven't seen?

I plan to post another spar topic, completely different idea, more to share than ask this time, so we can consider this one closed Thank you all again!

 

Before finally interring this thread, could I suggest that you use the photograph of the mast bending to determine the force that the mast was being subjected to? You have a static bending jig that will give a fairly accurate idea of how much force it takes to achieve the bend. Such knowledge may be useful on several ways.