[barnacle]

I do not see where there would be a problem with going over awl grip. If the bottom has never been painted be sure to use the sandless primer first or the bottom paint will not stick. As for barrier coating when we sand a bottom down to gel coat we do barrier coat them. Will it help I dont know. From what you read it does. I did it to my boat. It would not be a bad idea to do it since there is no paint on it now. That would be better then 5 years from now saying I should of.