Mike:

The hook at the top of the sail will scrape down the side of the mast. I have put my sail up hundreds of times and there is no sign of wear on the mast of my Tiger.

Maybe you have a sharp thingy on the hook. Check to see if there is something you could file off and sand smooth so there is nothing that could scratch the mast.

Sorry if you already tried this I cannot figure out why you are messing up your mast.

Later,
Dan