Originally Posted by Brent Swain
To reduced maintenance ,start with clean steel . I get all my plate wheelabraded and primed with cold galvanizing primer, 87% zinc dry film by the steel supplier. My current boat was done that way and still has the 29 year old paint job, no problems. I gave mine 30 gallons of epoxy tar on a 31 ft boat, plus a coat of enamel every few years. Moitessier said the French navy puts ten coats of paint on before launching. The thicker the better. Most steel boat maintenance problems come from too thin a paint job, or painting over rust or mil scale. For many commercially built boats in BC, it comes from zero paint inside. Spat foam is not adequate protection for the inside of a steel boat. Three or more coats of epoxy tar inside before spray foaming is needed.
Wasser makes a urethane tar which is just as good as epoxy tar, the same price, and much more forgiving in recoat times. They also make some good zinc primers.
Flat well painted surfaces rarely chip. Corners are the main source of paint chipping. Trimming all outside corners with stainless reduces maintenance by roughly 80%. That is why I put stainless cabinside handrails on the edge of the cabinside, instead of inboard. It also makes things a bit safer
To minimize maintenance, designers should simplify things as much as possible, eliminating corners and nooks and crannies, or do them in stainless where possible. I met a guy with a Waterline boat with a sharply reversed transom. He had trouble keeping paint on the sharp bottom corner of the transom. It was constantly being chipped. I suggested he replace the bottom tip with a stainless copy, or put a small vertical bit of stainless transom there. It would look good.
When working with a heavy material, the trick is to minimize overhang, to maximize the WL length to weight ratio. A large sail plan also helps a lot.
Origami eliminates the chines in the bow and stern, eliminating the flow of water across hard points there. Midships chines are more parallel to water flow , altho one can always radius the chines there. Other wise you can make any hard chine hulk shape using origami methods. Mine sail well and have been well proven over decades.
I put a plexi window in the top of my built in tanks, so you can see the inside of the tank which is the hull skin , any time you lift a floor board. With removable tanks, you don't get to see the hull plate under them , until you have a problem and are forced to remove them, a problem you don't have with built in tanks. I make the inspection plate large enough to let me stick my head in, and see every inch of the inside of the tank and to reach every inch of the tank inside.
If I were rich I would consider aluminiumn cabin tops. I would never make the transition at the hull deck joint, which takes the entire twisting loads of a hull and is wet and a bad place for corrosion and deck leaks . As cabinsides on a sailboat are small and light especially with ports cut out I would make the transition to aluminiumn at the cabinside-cabin top point. I wouldn't consider cored fibreglass, as you would have to bolt your gear onto it , instead of welding.
There are no particular concerns about wiring. I suggest a plastic conduit along the hull- deck joint before foaming. Then you can pull whatever wiring you need thru any time.
I use big tabs, welded to the hull to bolt the bulkheads on. On the last boat I built, I tightened a piece of rigging wire, parallel to the centreline and waterline with a come along. Then I measured the spacing of bulkheads along this ,put a laser pointer on a square and used that along the wire to position the tabs for my bulkheads. It was extremely quick and simple.
I hang my interior off the bulkheads, on 2x3s fore and aft, nailed to the bulkheads.
More to come . The smoke from the leper colony ( Smoking section) is starting to blow into this pub .