Yah, I had the same problem also when I converted from the old TheMightyHobie18 Rudder Castings to the new system in 1988 (I believe). The two nylon adjustment screws act as a point load and punch holes onto the "old" EPO rudder blades exposing the core ....

As recommended above I used WEST Epoxy w/ fillers and on the last coats I used some small pieces of fiberglass cloth w/ WEST Resin .... then sanded it fair.

Now how did I prevent a re-occurance???? I'll explain a trick someone else taught me ....

First, take those nylon screws out and throw them as far from the boat as you can!!!!

Next, I did have a reasonable idea of where/how much rudder rake I needed, which is what those screw were SUPPOSE to control. So upon a suggestion from a knowledgable friend I wrapped the rudder blade in "Plastic Food Wrap" ... placed/squirted a large glob of silicon onto the bottom of the rudder casting where the nylon screw HAD been ... and then pressed the rudder blade into it's proper down position ... allow to harden over-night. You have a semi-instant flexible bumper ... If you don't like the rudder tune, remove the silicon and try again ... stretchable "Shrink Wrap" will also work ... {you may wish to repair the blades ... reinstall them ... measure the rudder rake w/ the set screws ... mark the casting for the leading edge of the blade ... remove and dispose of the nylon screws and then do the silicon trick if you do not have a "good" feel for the rudder rake setting ... just an idea}

My TheMightyHobie18 has been raced/sailed 12 of the last 20 years (it was apart for 8yrs as I sailed my P19 but that is for other reasons...) I have redone the silicon twice in 12yrs of sailing effectively. I'm thinking of redoing it in the spring as I'm thinking of coating my origonal "old" EPO rudder blades w/ WEST Epoxy and then painting them for UV protection (a nice white I think) So it seems to be a good solution for this problem to me .....

Give it a try .... it's not permenate ... requires no holes ... is easy to do ....

Good Luck
Sail Flat, Sail Fast, Sail SAFE
Harry Murphey
H18Mag/#9458, Fleet54/Div11
P19MX/#86, CRAC-Open Class

PS/FYI: I have done alot of WEST Epoxy work/repairs and then Gellcoated .... You need to expose the curing Epoxy to a good 3-4 day min of bright sunlight so the UV's can complete the curing of the epoxy through the "Amine Blush" phase has been my experience ... (I have two bow repairs that I have been exposing for several years now .... I quess it's time to get some gelcoat w/ wax and properly finish the repair ... HA HA HA ... but true.)

PS2: Cut the "plastic wrap" along the trailing edge of the rudder blade ... gently pull the blade out of the down position .... then remove the "plastic wrap" layer by layer ... you may need to leave the last layer in place and just trim off the excess material ...