hard bottom paint

[rhody98]

Not an expert but here was my thinking. The hard paint cant go over a soft bottom paint, so in my case I sanded down to the gelcoat immediately under the existing ablative. My thinking on applying the barrier coat 1st rather than just going with a hard bottom paint is mainly preventive....its easy to sand into the gelcoat further than you think so the barrier coat will protect what's left of the gelcoat if the boat is in the water for any time.

If the situation changes where it goes on a mooring, then as Hermit noted an ablative can be applied over the top after sanding to roughen. The barrier coat is already there under the hard coat to prevent the gelcoat from blistering. Extra time and money but seems prudent and potentially time-saving in long run.