I make my own mast boot by using elastic bandage(similar to an ACE bandage) the type that adheres to itself. I wrap it around the mast and partners. I coat it with rubberized type coating paint/material. I use the coating that you would coat anchor chain. I have also used the liquid whipping coating as well as tool handle dipping compound. I use what ever I can easily find at West Marine or the local hardware store. I make sure that I apply a layer of the coating to the mast before I start wrapping the bandage and I continue to coat he bandage as I wrap it. The result is a good seal that flexes with any mast movement/shudder. I sometimes touchup the coating if it gets abraded by lines/sheets over time.
I have also used Rescue Tape to make a mast boot or to seal leaky mast boots. I got two inch wide rolls at the Miami Boat Show several years ago. I have found that in conjunction with the one inch wide rolls that they sell at West Marine works well at the base of the mast to get around turning blocks and fittings. I really like this product. I have used it as a temporary patch on hoses, to wrap electrical connections, and other applications around the house, on my car, and on the boat. I keep a roll in my cars and on the boat. I helped a stranded motorist in the parking lot at Costco with a leaking radiator hose.
