Guidelines for Building a Cradle for a Sunfish Sailboat on a Trailer

WRITTEN BY:
Corpus Christi Sailing Center, Inc.
PO Box 995
Corpus Christi, Texas 78403
(361) 881-8503
http://www.constant.com/sailing

• We are a Sunfish Dealer in Texas and we ship Sunfish parts worldwide. Please call us for information about or parts for your Sunfish.
• No guarantee is implied and these guidelines may be copied as long as all the previous information is included in the credits.
• These guidelines were written to help Sunfish owners (and other small sailboat owners) build a cradle on a trailer for a Sunfish carried in the upright position.
  

ILLUSTRATION #1:

You should choose the best materials and take all shop safety precautions when you build a cradle. These guidelines should work with most trailers and small sailboats, with modifications as needed.

TRAILER MANUFACTURERS:

There are several trailer manufacturers, such as Trailex and Dilly, and of course lots of home-made trailers. No endorsement is made for any particular trailer but here are the three boat trailers that are relatively inexpensive, come with lighting and work with Sunfish. These trailers are available from an established mail order company - Harbor Freight.

990 LB. CAPACITY 4 x 8 FT. FOLDABLE UTILITY TRAILER / ITEM 35966-1VGA http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=35966
Cost = $270 with 12" wheels.

I believe this is the best trailer that Harbor Freight has for adding your own Sunfish cradle. It has the larger 12" wheels that offer a smoother ride and are better/safer for highway towing. It also tilts for easy loading of a small boat and the simple square design of the frame makes it very easy to build a cradle for a Sunfish or any other small boat using these guidelines. You also have the added benefit of being able to easily remove the boat cradle and convert it to a utility trailer. It also folds up for storage in a 2ft. by 5ft. space!

860 LB. CAPACITY 3-1/3 FT. x 4 FT. MINI UTILITY TRAILER / ITEM 42708-0VGA
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=42708
Cost = $180 with 8" wheels.

If you just need a trailer to haul your Sunfish a few blocks down the street to the waterfront at slow speeds, this trailer would work. However, this trailer is too small for towing a Sunfish behind a car on the street or highway. While a cradle can be built that will hold a Sunfish, the tongue is too short and the cradle would have to extend past the rear of the frame. This would put the Sunfish's weight too far behind the wheels, create a negative tongue weight and would cause the trailer to wobble or oscillate while going down the road.

TIME-TESTED DESIGN HANDLES UP TO 600 LBS. / ITEM 5002-0VGA
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=5002
Cost = $300 with 8" wheels.

This is actually a real boat trailer and comes with two runners and a center support roller. This trailer is used by many Sunfish owners just the way it is. It is my opinion, however, that the runners and center support roller are not in the correct location for supporting a Sunfish hull (see "Important Point # 1" below). At a minimum, I would replace the runners with longer, fitted cradle boards and move the brackets and those boards toward the outside edges of the Sunfish. If you wanted to build your own cradle with this trailer, you would have to build a special cross brace to hold the front brackets as the trailer frame narrows at the front.

CRADLE MATERIALS:

It is suggested that you use Womanized pine for the cradle, especially if the trailer is to be stored outside. This is the same wood that is often used on outdoor decks.

While considering the dimension of wood that is best for your cradle, you should determine if you need extra height to keep the Sunfish from rubbing the trailer wheels. If you have to mount the cradles high off the frame to clear the wheels, you should consider using a 2x10 or 2x12 instead of a 2x8 for the cradle. The minimum size should be 2x8 as this dimension still gives you strength after the cutout has been made.

Although L-brackets are shown for illustrative purposes, you should use U-brackets as they provide extra strength. These brackets should be attached to the trailer with either carriage bolts or U-bolts as shown in

If possible, you want the cradle boards to rest on the trailer frame for extra stability. If this is not possible, you will have to use longer U-brackets and you should insert an additional piece of wood between the cradle and trailer frame.

ILLUSTRATION #2:

Important point #1:

The two cradle boards should be mounted close to the outside edges of the Sunfish (See: Illustration #1), keeping in mind that they will also need to be bolted to a suitable position on the trailer frame. Mounting the cradles this way shifts the contact point on the Sunfish to the outside of the boat which is much stronger than the middle or the bottom (keel) of the hull. Most importantly, this avoids putting weight in the wide flat areas or keel which would damage the internal foam blocks that are located inside the hull. Continuous flexing of those foam blocks can result in them detaching from the hull and/or deck. The same thing happens over time to many Sunfish that are sailed in heavy seas.

I also don't recommend supporting the Sunfish at any other point, like at the bow with a wench post or under the keel with any kind of roller. If too much weight is placed on the bow or the trailer bounces too much, and these supports are in place, those supports can cause damage to the hull, deck and foam blocks.

If the cradle boards are at least 4 feet long, cut to fit the hull, mounted towards the outside of the hull and centered on the length of the Sunfish, you will have plenty of safe support for the Sunfish.

You might have seen some trailers that have two cradles athwart ship, that is, across the hull, instead of from bow to stern. This design will also work but it does require that you find the optimum points that will give the best support while avoiding any deck hardware, coaming, etc., and avoiding putting weight on the internal foam blocks. Because the cradle boards are mounted athwart ship, this design also creates more wind resistance while towing.

Important point #2:

You must make sure that the curved (cut out) part of the board matches the curve of the Sunfish hull longitudinally. Here is an easy way to trace the longitudinal line to be cut:

1. Turn Sunfish upside down on level ground.
2. Determine the best spacing between the boards - mounted as far outboard as possible and that will match appropriate trailer frame attachment points.
3. Make pencil marks on the trailer frame with this distance.
4. Draw longitudinal (bow to stern) pencil lines (about 4 ft long) on the hull at that spacing. Keep in mind that the boards will be mounted about half way between the bow and stern.
5. Place the (uncut) cradle board on top of the hull along that line and in a vertical position. (See: Illustration #3). Because the hull is curved, it will only be in contact at the middle of the board on it’s inside edge.
6. With a carpenters level, if available, level the board and hold it in place. If no level is available, you can "level" the cradle board by looking down the length of the board and line it up with the horizon.
7. The next step will require either a ruler or a compass (the type that is used to draw a circle).

COMPASS method:

1. Place the pointed end on the pencil mark on the hull and the pencil end on the board.
2. Move the pointed end along the pencil mark on the hull while moving (marking) the board with the pencil end.
3. You will have to determine the best width of the compass angle, keeping in mind that you want to end up with as thick a cradle board as possible after the curve is cut out. You can see that this method transfers the curve to the board in the "Close up" in Illustration #3.

ILLUSTRATION #3

RULER method:

With the ruler in the vertical position, slide it along the pencil mark on the hull while keeping a pencil at a specific point on the ruler while it marks the board.

Whichever method you use, you only have to do this to one board. After you have cut out the curve in one board with a jig saw, coping saw or band saw, (See: Illustration #4), just lay that board on top of the other and trace the curve to the other board.

ILLUSTRATION #4

CREATING A LATERAL SLOPE:

While it is not absolutely necessary, you should consider putting a lateral slope to the cradle because the Sunfish hull has a slope to it and the curved cut on the cradle board is flat. This will spread the load out over the 2" width of the cradle, instead of just the inside edge.

This can be accomplished in a similar process as you used to create the initial curve.

1. Place the previously cut cradle on the hull in the correct location and make sure it is vertical.
2. You will notice that on the OUTBOARD side of the cradle, there is a gap between hull and the cradle.
3. Measure the width of that gap (1/2 inch or so) in several places.
4. Now on the INBOARD side of the cradle, pencil in that distance (gap) all along the curved cut.
5. With a coarse wood file, remove the wood between the pencil mark and the OUTBOARD edge, being careful to preserve the OUTBOARD edge.
6. Even after all that measuring, it may involve the repetitive process of filing some wood and "eye balling" the fit. Keep in mind that it does not have to be exact as you will eventually place some thick carpet over that surface.
7. Using the U-brackets, mount the two cradle boards on the trailer at the previously measured locations. I would suggest that you use two carriage bolts at each mounting point on the cradle boards. This will give extra support and prevent all parts from "drifting".

PLACING CARPETING ON THE CRADLE:

The final step would be to place some thick carpet strips (approx. 6" wide by 4 ft + long) over the top edges of the boards and tack the excess on the vertical sides of the boards. Some people even put extra foam strips on the top of the board and under the carpet. If you want to do this, you should use closed-cell foam to avoid absorbing rainwater. To keep from scratching your hull during transport, avoid putting any tacks on the part of the carpet that will be in contact with the hull.

HOW TO SECURE YOUR SUNFISH TO THE TRAILER:

There are many ways to tie your Sunfish down for road travel. A convenient way is to use 2 or 3 straps that are often called "web-ratcheting". They are wide straps of nylon webbing with a ratcheting mechanism that makes it easy to tighten them around the boat and trailer. They are relatively inexpensive and are available in sets at most hardware stores. The bow should be secured to the trailer with a line or web-ratchet.

BUILDING A CRADLE TO CARRY YOUR HULL UPSIDE DOWN:

If you want to transport your Sunfish in the upside-down position, these instructions will also work - you just won't have to cut as deep of a curve in the cradle board to match the curve of the deck. You can also mount the cradle boards further apart to support the deck near it's edges, being careful of the location of the coaming and other deck hardware.

HOW TO SECURE YOUR RIGGING ON TOP:

Again, you get to pick from several choices. Some people just roll their sail around the mast and spars and just put them right on top of the deck and tie it down. This can work for short trips but you run the risk of wearing holes in your sail and scratching your deck from the gooseneck and spars rubbing against the deck. At a minimum, you should put soft material, like a life jacket, in between the rig and deck.

The best way is to use any method that gets your rigging off the deck, while still offering support and stability - and there are many ways to do this.

For the forward end of your rigging, you can build a yoke that fits into the mast hole (See: Illustration #5) or even the daggerboard slot. You must be sure to tie the rigging to both the "Y" and to some part of the hull (mainsheet cleat?) so the "Y" won't just slip out with your rigging attached when moving down the road.

If you have an upright winch post at the front of your trailer, you can create a yoke to fit that (sometimes you can use the existing rubber "Y" by just rotating it up). The rear of the rigging should be padded too so it won't scratch the hull or be rubbed by the edge at the transom. If you're a bit creative, you can utilize the gudgeon by fabricating parts that will fit into the holes and support a yoke that raises the rigging off the deck. If you create a simple rear yoke, it would probably span the aft end of the boat and just just rest on the deck so you would have to pad it to protect the deck and devise some method of tying it down to the deck.

ILLUSTRATION #5:

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HOW TO STORE YOUR RIGGING UNDERNEATH YOUR SUNFISH:

You can store your rigging underneath the Sunfish. If you do this, you might need to make the cradle higher. You should be careful, however, as you don't want to raise the center of gravity of the trailer/Sunfish too much as you will run the risk of flipping the trailer while making turns or contending with cross winds. The most convenient and safest way to store your rigging underneath your Sunfish is to use a 6" or 8" PVC pipe, permanently mounted to the trailer. PVC pipe will help protect your rigging from road gravel, tar, etc. The 6" PVC pipe (much less weight and much cheaper than 8") will necessitate that you either remove the gooseneck each time you de-rig or you will need to cut a slot into the 6" PVC pile to allow the mounted gooseneck to slide in. Since some PVC pipe lengths are less than the length of your spars, you would also have to buy two pieces and splice them together with a PVC fitting.

Here are two Web Sites that show other designs for Sunfish cradles (athwart ship) equipped with PVC tubes for rigging.

Inverted: http://www.cattanach.org/sunfishtrailer.html
Regular: http://www.castlecraft.com/images/trailex-ut250e-menu.jpg

A SUGGESTION ON HOW TO ROLL YOUR SAIL WITH MAST AND SPARS:

Most folks just put the two spars together (with or without the mast still in gooseneck) and start rolling the sail around the spars. When completed, the sail is on the outside of the rigging. This leaves the sail vulnerable to chafing between the spars, mast and gooseneck and any hard surface that the entire rig is placed upon. 99% of the damage to sails occurs from rolling up sails this way!

An alternative method, and one that will add years to the life of your sail, is to place the two spars together, as before, but instead of holding onto the spars and rolling, lay the spars down on the ground with the sail lying off to one side. Go to the outer corner of the sail, where the leech has been folded in half, and begin rolling just the sail so that you are creating a roll that is parallel to the spars. When the sail is completely rolled up, it will be next to the spars and not wrapped around them. Use 4 or 5 pieces of soft material (2 ft. strips of cloth work fine) to tie everything together using square knots. This method will also prevent your sail from catching air when riding down the road on your trailer.

When you place your rolled up rigging on the trailer, just place the exposed spars on the bottom so the sail won't be in contact with any hard surfaces.

The Corpus Christi Sailing Center, Inc. hopes you find these guidelines useful.

Please call us at (361) 881-8503 if you need Sunfish parts or other advice on keeping your Sunfish in the "swim of things".


Regards,
The Staff at CCSC