I just did it.....
First of all, don't believe all the information you read on the internet. Another web site gave West Marine part numbers for plastic shackles and sail slugs for use on a Mac 25 sail. They didn't fit! I discovered this AFTER I had already melted the holes through the sail 12" apart to fit grommets! My recommendations:1. Use West Marine 3/8" Sail Slug #2690881. You'll need 22 of them. The 1/2" Sail Slug #2690931 may also fit, but I didn't experiment with that larger size. Also use Plastic Shackle #2690964 with the slugs.2. Don't melt any holes into the sail until you've actually got a plastic shackle and sail slug in position on the sail to confirm proper position. When you're satisfied, insert the screw into the plastic shackle to punch a hole through the sail material. Remove the shackle.Using a soldering iron with a 1/4" tip, melt a hole through the screw hole in the sail material. The melted hole will be almost like a grommet as the heat will mold the hole into one solid opening. A grommet isn't necessary. 3. Install the sail slug and plastic shackle. That's all there is to it, but remember,"DON'T MELT ANY HOLES INTO YOUR SAIL UNLESS YOU HAVE THE PARTS IN POSITION ON THE SAIL TO CONFIRM PROPER LOCATION OF THE HOLE." I made the mistake of melting larger holes and installing brass grommets first. Big, big mistake. The grommets are unnecessary, as you will see for yourself.West Marine has a "No Questions Policy" on returned parts. Go get yourself the plastic shackles and solid plastic sail slugs AND the slugs with the stainless bails to try them out first. What you don't use can be returned to the store. I had to buy my slugs off the West Marine web site after confirming the size I needed because none of the Bay Area stores had enough of them in stock. Hope this information helps you. Anything is better than sliding that rope up and down the slot.