I'd like a recommendation for a horn cleat to be used to tie off the halyard and also a recommendation as to where and how to attach the cleat and, finally, what size & length halyard to use. Many thanks!
I got the cleat for my mast at Lowes. It's a heavy duty plastic and about 5" from tip to tip. I predrilled holes in the mast and attached the cleat with stainless steel screws. It's positioned roughly 4' from the bottom of the mast. I bought the line for the halyard from a local West Marine - 1/4" diameter x 25'. I can't recall what it's made of but it is very flexible with no stretch.
I used the 3M 4200 sealant 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.