I'd like to add a cleat on the mast for the main halyard. Not sure how to do that. Since I can't access the inside of the mast for any type of bolt, what do I use to screw the cleat to the mast?
You can use rivets, preferably monel. Or SS sheet metal screws. I glued my cleat in place with expanding Gorilla Glue to, to seal the holes and add strength.
That said, today I wouldn't add a cleat. There's a posting about tieing a line on the mast instead. I like that much better.
I used the 3M 4200 sealant (caulk is likely just fine) behind the cleat, and fastened it on with #10 stainless steel sheet metal screws – I had to pre-drill the mast with small pilot holes.
You can use rivets, preferably monel. Or SS sheet metal screws. I glued my cleat in place with expanding Gorilla Glue to, to seal the holes and add strength.
That said, today I wouldn't add a cleat. There's a posting about tying a line on the mast instead. I like that much better.