I purchased a new sail for the Dart 18 from Whirlwind. The grommet at the top of the sail is thicker than the opening on the halyard ring. The halyard ring looks like this, exception mine has a spring loaded bar that flips down to lock:
I tried simply bending the hook open enough to accept the new sail, but then the bar doesn't clear far enough to close. Any thoughts on a solution?
I have the same halyard ring as in your photo on my Dart 20 and I bought a whilwind mainsail in December 2020 and it fits perfectly. I've never seen a halyard ring like the one you described. Maybe get a halyard ring like the one you have pictured? Or do away with the spring loaded bar. What purpose does the spring loaded bar serve?
If filing down isn’t an option, consider having the grommet replaced with one that fits the halyard ring. A sailmaker or a marine shop drift hunters can assist with this.