Hi, I've just bought my first outdrive boat SS Portofino 31 with twin 290 drives and want to antifoul the drives. Different shops tell me different things. One tells me to use etching primer first, then a normal primer then the antifouling. Others tell me to give the old antifouling a rub down and apply special antifouling for outdrives. Any input welcome as I have no experience and want to get it right to avoid costly corrosion problems.