primer over well-sanded gelcoat
. Fill any big dings, low spots, etc. with an epoxy
filler. Sand well with 120 grit, spray some water
on the boat and look at the shine to see if there are any remaining larger defects, flat spots, etc. Then sand with 220 grit to make it paint
ready. Use a 2-part linear polyurethane paint
with the appropriate accellerator to kick off in cooler weather
. Use the appropriate thinner for your paint. All of these lpu paints are sold as a system. Stick with one brand and its components. Roll and tip the lpu and check for any problems: drips, bubbles, fisheyes, captured bugs, etc. I there are no problems, you can put the next coat on the following day without sanding
. I always find some problem, requiring me to lightly sand the whole painted section once more. Try to arrange the painting to do sections, rather than try to paint the entire boat in one day. Get at least two coats, preferably three, to give you a finish that will hold up to dropped winch
handles, scuffing the finish with a dragging chain or dinghy
, or a hard landing on the dock
. Since you are using the same amount of labor that you would have expended on a single
part finish, and since the lpu paint has at least a decade's longevity, you will have saved a huge amount of time that can be expended going sailing instead of painting another coat of single-part paint every three years.
LPU paints have the highest color retention, expansion/contraction coefficients, abrasion resistance, and value of any coating available to boaters. Save the single
part stuff for inside the boat.