I had an I-20 for awhile and did not experience this problem myself but heard about a few folks that did. The cause was the owners did not keep the through bolt tight on the mast rotator. This allowed the rotator to have some slop and thus causing some wear. You can either fix this by adding some epoxy to the holes on each side of the mast and then cleaning this up with a drill bit or maybe epoxy a compression sleeve similar to the one used on the diamond wire tang on top of the mast. I would at first just try to fill the void with epoxy instead of using a compression sleeve. The use of a compression sleeve would probably mean you should change the size of the bolt or increase the hole size. You might be able to get a smaller size equal strength bolt made of some exotics. (Titantium or high resistance stainless steel 17.4 PH. 17.4 PH stainless is stronger but subject to corrosion if surface is not polished, passivated and properly maintained. You can not keep 17.4 SS submerged in salt water otherwise it is OK)



Good luck with the reseal of the rotator bolt.