Wayne, I'm trying to avoid having to pay the high price of the adhesive backed patches or tape. It would be easier, yes. But, we just don't have the funds. So, I have one particular area that is almost 10"x12" that has several holes from the size of a dime to a baseball. There are also a few spots that had been sealed by the previous owner with some sort of caulk that has now come loose and need to be re-sealed. And a few new small holes from a pitch fork! So, as you can see, it could get pricey using those premade patches.
I the RTV silicone didn't hold at all. I would need to get some sort of primer like acetone? to make a tacky surface. I'm hoping the 3M marine grade sealant will work. It arrives on Tuesday. The gorilla glue is holding well. But, I don't think it would stand up to the water. I even made a sample using shoe goo. But, unfortunately its very toxic. Wish I knew what the previous owner used. It looks like it held up for at least a year or two or three.