Originally Posted by mikeny
Do you think it would be possible to router out the cracks and epoxy wood in them
Consider that the MAIN stresses in an unstayed mast are either compression or tension stresses induced from bending. A loose analogy is that there are parallel fibres running from the top of the mast to the bottom of the mast and that each fibre is continuous.
The cracks, due to drying of the wood, run parallel to the fibres and do not hinder the ability of each fibre to carry a tension load.
The opposite side of the mast, ie the compression side, it does not really matter if there are cracks there as the load and resultant stresses act vertically down. Note there is a slight consideration if under compression loading that the fibres, if you will allow the weak analogy, could separate, and reduce stability.
But routing the crack out will in fact cut through the fibres and reduce the tension strength.
If you are interested in aesthetics, ie the look, you could fill the cracks as they are now, without reducing the strength of the mast
(Of course this is simplified as there will be some shear flow stresses due to bending acting vertically , some horizontal shear stresses due to the horizontal sail loading and some perpendicular to the mast shear stresses created from the weight of the mast when the boat is healed, perhaps some stress concentrations due to the fastening of the mast to the hull issues, but tension and compression will produce the highest loading in the mast)