Sailboat Re-finish and forehatch addition

[Chris Krumm]

Posted this on Materials forum with no response, so I'll try it here:

I recently purchased a 1986 Holder 20 (think precursor to Ultimate 21, w/ less sail area and beam) in good structural shape, except repainting hull and deck is in order. Boat will be mainly trailer sailed in fresh water. Finish is original white gelcoat w/ molded in diamond pattern non-skid areas on deck. No blistering on hull. The deck has a few hairline cracks in the gelcoat near some hardware points, but core & laminate is sound. Interior is flat white gelcoat stucco.

The hull below the waterline is sanded to 120 grit from the previous owner removing old bottom paint, as are the rudder and drop ballast daggerboard. Deck and cabin top have had a number of hardware relocations and spot filling, so I'm looking at sanding down the minimal molded in non-skid and repainting the deck w/ new non-skid compound.

First question: What do folks recommend for the paint system below waterline, above waterline, on decks, and on interior? Should I go with an epoxy barrier shield before painting?

Second question: I'd like to add a 19 x 19 Bomar or Nibo foredeck hatch on the sloping cabin roof. I'm concerned this will interrupt a deck compression load path from the forestay to the mast base. My thought was to laminate 2 foam "beams" either side of the companion way at the bulkhead and run them either side of mast and foredeck and then have them meet at the bow, below the stemhead fitting. Cap them with uni carbon and some biax. Think this is in order, or am I worrying too much?

[gonzo]

A structural ring around the hatch would be good insurance. Besides the compression force, cutting a hole may make the deck springy and cause leaks. Since you have the bottom all sanded, the hard part of the job, a barrier coat would be easy to do. It can prevent blistering in the future. However, if blisters haven't shown up by now, you are pretty safe. On the topsides, the paint choice depends on your expectations. An industrial oil base enamel is the easiest to apply but won't last more than a couple of years. Polyurethane enamels are more expensive and tougher. You can also spray gelcoat with duratec ( http://www.cris.com/~westsys/gel-rep.shtml ). For the interior I like water based house paint. It has mildewcide and it is EPA approved for human habitation, unlike many marine paints.

[Chris Krumm]

Gonzo,

Thanks for your reply. The foredeck and coach roof have a lot of curvature. Since I'm looking at a rectangular hatch, I'll end up with have a thick (~ 1.25") fore-aft curb port and storeboard on top of the foredeck, along with the athwartship build ups that will be thick at the edges and thin at the crown. After coving and fiberglassing with biax, think that'll be sufficient to recover strength I lose cutting the hole?

Regarding paint. I have a good heated shop, but prefer to do a roll and tip job as opposed to spraying. I think I'll barrier coat the bottom and hullsides. Any particular recommendations for barrier coats and tough 1-part polyurethane enamels?