[SteveS]

Hello:
Here is my first post. I also have a Capri 26 and have had problems keeping the mast from inverting. I don't think my spreaders have wiggled so much but I may not have as many miles on the boat. After retuning the mast about a dozen times per the Catalina directions without any success, I (with the help of a rigger) figured out that the deck was compressing under the mast. While the mast is off the boat snug up the 4 1/4-20 screws that hold the mast step in place. I did this and when the mast was up and tuned the nuts on the bottom were loose, particularly the aft ones. My solution was to beef up the mast step area in the cabin sole and epoxy some vertical 3/8" diameter aluminum rods in the deck to take the compression load from the mast step to the compression post inside the boat. After doing this operation the mast maintained its prebend and I overstood the weather mark 2 or 3 times in the next race. There is a big hole in the deck for the mast wires and after 20 years in the rain the mast step was a little soft. I also poured lots of git-rot in the holes to hold the aluminum rods in place. The hardest part was filing the rod ends flush with the deck.
Good luck and Happy Sailing
Steve