I had the same problem. Having already had the mast up, I knew that shortening the mast by about 3/8¡± would not leave the standing rigging too long, nor would it reduce head clearance in the cockpit unacceptably, so I cut that corroded portion off with a metal cutting blade on a Fein multitool and made sure to square it all up nicely. I do note that the cut-off piece broke in two as it was coming off, i.e. I do not think I would have been better off leaving it and trying to patch with epoxy. That¡¯s a pretty stressed area, I think.
I¡¯ll try to post some pics later, but I sanded the mast back to bright shiny aluminum and wiped/cleaned it very well and gave it two coats of Aluthane from epoxyproducts.com, then top coated with four coats of spray-can Rustoleum clear satin enamel. Time will tell, but it looks really nice and new.
