Although "over-strengthening" the mast step isn't a bad idea, JohnCT's method allows some desirable "slop".Yeah, a fix where I don't have to cut holes or remove anything is preferable. There's definitely some play in my mast step, so I think I could patch it from the inside. L&V, when you say cloth tape, do you mean fiberglass cloth? I haven't heard of that, bit then again, I'm still new to a lot of this. Can you link to a product you like?
Where I sail a lot of the Laser sailors put a plastic disc in the bottom of the mast step to protect it from wear and help the mast rotate. Apparently a pringles lid works well.To allow the mast to rotate against the mast's black (plastic) cap, the mast step's original bottom should remain the same—or smoother. It seems extreme for a Sunfishbut a Teflon "button" has been long available for catamarans for that very purpose.
As a followup. Sanded it down, marked out the holes for the PVC grommet and glued and screwed it down with the 3M 5200. Rock solid and waterproof. With some help from another forum member, got the strips for the mast and a base plastic for mast and this is now better than new and looks professional.New to this forum, and had mast step issue with my sunfish. This forum and topic has been very helpful.
Mine had cracked at upper 1" of the step, and lost some fiberglass and gelcoat. This lead to a leak in the upper portion of step.
I tried to find balloons of the right diameter, but my local party store's balloons were too small in diameter.
Found a length of 2" pvc pipe that was just larger in diam. than a sunfish mast.
Ground out the upper area with wire brush on drill. Laid in a couple of 2" strips of wetted fiberglass mat around the diameter, using colloidal silica as thickening agent. Stuffed the area behind the strips with fiberglass mat and epoxy. Made sure the diam. stayed bigger than the pvc pipe. Let it harden. Scuffed it up and laid down another strip that also came up over the deck a half inch (notched cuts for relief). Placed the pvc pipe in the step, all the way in, after I had taped wax paper around it. Stuffed more thickened epoxy into the area between pvc and step, where gaps. This left a small raised area of fiberglass and epoxy above the deck height that I now need to sand down. Created a pvc grommet that I will 3m5200 and screw to the deck. The area is strong, smooth, looks good and I could pull a vacuum in the hull, so no leaks.