Sunfish Rudder Conversion

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The Sunfish has been built since 1953, first in wood and then in fiberglass. The original rudder releasing mechanism was made of bronze, and had a shorter height vertical plates for the wooden boat compared to the fiberglass boat.

Here is 1953 Alcort Sunfish ZIP, number 13 of the first 20 pre-production Sunfish built.

In 1972 the Sunfish had a new rudder blade, tiller and attachment hardware. The old style rudder could pop loose under heavy load, and the new style rudder offered better handling and performance. Many sailors now opt to convert their old style rudder to the new style, another reason being that new style rudder parts are easier to find.

Old style fittings on left, new style on right.

From Sunfish Sailboat Restoration

Old style uses a vertical hinge plate, hinge pin, deck spring plate, keel plate and carriage bolt. The weak point is the groove on keel plate that captures the vertical hinge plate. The attachment plates on the deck and on the keel both have wood backer blocks inside the hull. You also might see a small screw hole on the deck where the keeper chain for the rudder pin was attached. The shoulders of American roadways are littered with Sunfish rudder hinge pins. Chain is missing from this pin.

From Sunfish Sailboat Restoration

New style rudder is uses spring tension to hold it up or down, it pops up for easy beaching. It also uses a pintle and gudgeon design, plus the blade has more surface area and a better profile.

From Sunfish Sailboat Restoration

In this picture we have the new style rudder and tiller on the top, in the middle a few of the parts needed for a conversion and on the bottom the old style rudder and tiller.

From Sunfish Sailboat Restoration

To change out fittings you either have to split the hull/deck seam and re-epoxy it back together just right, or install an inspection port to remove backer blocks and install metal backer plate. The easiest method is the inspection port, plus if your boat is that old it is a good place to sponge out any water.

APS and Yankee Boating Center sell most of the parts needed, and you can gather other parts from ebay, craigslist or the Sunfish Forum

You will need general DIY skills, be able to use a drill, wrench, jigsaw and screwdriver and not be afraid to cut a hole in your 40+ year old Sunfish.

From Sunfish Sailboat Restoration

Old style on top, new style on bottom, on the way to restoration.

From Sunfish Sailboat Restoration

Gather new rudder/tiller parts and deck hardware, or just buy a complete set up and add nuts and bolts. There are no parts from the old rudder that are compatible.

You'll need rudder blade, wood or fiberglass and tiller. Also spring pin, rudder cheek (black plastic or aluminum) with pintle and spring, 2 rudder tension springs, nylon washers that go between cheek and rudder and tiller straps and rudder. Nuts and bolts to attach cheek and tiller strap to rudder. Nuts and bolts to attach tiller straps to tiller. Stare at these pictures long enough and you'll see how the parts go together, attach cheek, drive in rudder spring pin if not already installed, install springs, attach tiller straps to rudder and tiller. If the pintle spring pin moves up vs down, that is okay, it works either way.

Tip: Don't attach tiller to tiller strap yet, wait til rudder is hanging on boat and you can get tiller set to proper clearance above deck.

From Sunfish Sailboat Restoration

Here is a picture of some of the parts needed. Note: Cardboard rudder template is not seaworthy.

From Sunfish Sailboat Restoration

You also need a gudgeon, gudgeon backing plate #85098, #8-32 stainless steel machine screws, washers and stop nuts. Take a look at the backer plate, see the little hump (channel) in it? That is the part you need, because it fits over the old carriage bolt hump molded into the transom.

From Sunfish Sailboat Restoration

And you need an inspection port. I used a port that has a 6 inch opening, so the port and ring measure 8 inches across. This access to the inside of the hull is handy to make sure any wayward water can be removed after sailing and the boat can be aired out.

From Sunfish Sailboat Restoration

From Sunfish Sailboat Restoration

From Sunfish Sailboat Restoration

To get started you'll need to unscrew the old deck and keel hardware. They can be unscrewed or drill out the screws.

From Sunfish Sailboat Restoration

Don't cut off the plates with a grinder, you'll cut into the hull. In this pic I had to use Marine Tex epoxy putty to fill in slots cut by previous owner with grinder. They were sanded later and the boat was painted. You may hit some internal foam, that's okay, it will not affect the structure.

From Sunfish Sailboat Restoration

You'll end up with a pile like this. Hang it on the wall or see if someone else needs it on ebay/craigslist/Sunfish Forum.

From Sunfish Sailboat Restoration

Once the old hardware is removed, pick the location for your port, usually 2-3 inches up from the stern. The cap for this port makes a great template to trace the hole. Unscrew the cap, and place it upside down on the deck, centered over where you want your port. This will be the template for the hole. Trace around the outside of the cap with a non-permanent marker. Tip: DO NOT trace around the outside ring, or else your hole will be big enough to drop in the entire port!

From Sunfish Sailboat Restoration

Tip: Measure twice, cut once. Drill a starter hole just inside the edge of the circle with a 3/8” bit.

In this picture we drilled more towards the middle of the hole. Afterwards we decided we could have drilled just inside the line and saved more of the disc, which can be held onto for possible use in future repairs.

From Sunfish Sailboat Restoration

Tip: If your deck is in nice shape, cover it with blue tape to prevent the jigsaw footplate from scratching it. Also protect yourself with safety glasses and a fiberglass particle mask. Using the starter hole you just cut, take a jigsaw and cut around the inside of the circle, staying just inside the line.

From Sunfish Sailboat Restoration

Tip: Remove the cutout, take a coffee break and admire your work.

From Sunfish Sailboat Restoration

You can now access the inside of your boat…although you might decide not to…here is a picture of a rotted wood backer block and part of its fiberglass holder.

From Sunfish Sailboat Restoration

INTERMISSION

From Sunfish Sailboat Restoration

Tip: Don't install the port yet, leave it off so you have more room to work inside the hull. Put some blue tape over the raw fiberglass and wear a long sleeve shirt to protect your arm (Remove tape before final port installation).Now you need the backer plate, gudgeon and hardware. A new backer plate usually does not have screw holes drilled yet for machine screws, what you can do at this time is line up the backer plate with the gudgeon and pre drill screw holes.

From Sunfish Sailboat Restoration

Place the gudgeon just below the lip of the deck/hull seam, centered on the transom. Drill through the 4 holes into the transom.

From Sunfish Sailboat Restoration

Add some marine sealant to the transom behind the gudgeon. Start a machine screw through one hole, then through the backer plate inside hull. Seal behind the backer plate also. You can use silicone but be advised it is hard to completely remove any excess and it might mess up a paint job. Put on a washer and stop nut and do not tighten. Put on other three screws and nuts. Tighten all screws. Oops, missed a washer :) The hump at the bottom is the fiberglass holder for the old rudder assembly's keel plate wooden backer block. And while we are here, note that someone put a drain plug on the bottom of the transom, we recommend NOT doing that. All that does is put a big hole inn the boat right at the waterline, and it is going to leak. Plus remember you just put a big inspection port on the deck where water can be sponged out if needed.

From Sunfish Sailboat Restoration

Put a bead of marine sealant around the port hole, install port and twist it 1/4 turn to spread sealant out. You can drill holes first if you like, then line them up after putting on sealant. Drill holes for machine screws. Install screws, washers and stop nuts. Tighten, but not too tight or the port can be warped.

From Sunfish Sailboat Restoration

Finished installation of gudgeon. We don't know where those handles came from or how they were applied, but we wish every pre 1988 Sunfish had them!

From Sunfish Sailboat Restoration

Clip on the rudder. Some pintles push down while others push up, there was not a standard. Either way works. Some pintles have a washer and cotter pin to retain the spring as well versus just a small snap ring, that is the best setup and a good upgrade.

From Sunfish Sailboat Restoration

Dry fit the tiller to the tiller straps. Drill hole for the aft machine screw, then adjust tiller to proper height off of deck. Keep in mind tiller will sag a bit under pressure and there is a bit of play in rudder system, so put tiller end by cockpit about 3 inches (fist height) above deck. If the tiller end is too low it can rub the deck and wear half moon shaped scratches into the gelcoat. Drill the forward hole and install machine screws, washer if desired and stop nuts. Note: If tiller is too high or low after a few sails, adjust it a bit. Move tiller fore/aft a 1/2 inch to drill new holes if needed, or glue dowel into old holes and redrill the new holes.

From Sunfish Sailboat Restoration

From Sunfish Sailboat Restoration

You'll also need to fill in the holes on the deck and hull from the old style hardware. Marine Tex epoxy is one good option, or thickened eopxy like THIXO or FLEXPOXY.

From Small Boat Restoration

From Small Boat Restoration

Float test.

From Sunfish Sailboat Restoration

Go sailing!

From Sunfish Sailboat Restoration

Yankee Boating Center, Annapolis Performance Sailing (APS) and Sunfish Direct sell most of the parts needed, and/or you can gather other parts from ebay, craigslist or the Sunfish Forum. If you have questions, add a comment here.

Personal Protective Equipment (PPE):
Fiberglass particle mask
Safety Glasses
Gloves
Long sleeve shirt

Parts: (sunfishsailboats.com or APS or sunfishdirect.com or Laser Performance for new, ebay or The Sunfish Forum for used).
Rudder blade with spring post
Rudder Cheek with pintle and spring
Tension springs
Rudder pivot bolt with plastic bushings bolt
Tiller straps with bushings, bolts, washers and stop nuts
Gudgeon with bolts, washers and stopnuts
Backing plate (pre 1972 with channel)
Inspection port (6 inch recommended)
Inspection port screws, washers and stop nuts
Tiller extension with hardware as desired

Materials:
Sealant
Blue tape

Tools:
Jigsaw
Drill with 3/8th inch bit
Screwdriver to match heads on hardware
Vise grips or socket wrench for stoputs
Extension cord
Electrity


For More Info on common restoration projects, buy our book The Sunfish Owner's Manual. It ships fast from Amazon!

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