Part One - Part Two

As webmaster of our class website, I have received numerous requests for want ads for rudder assemblies for the Mutineer 15.  Unfortunately they are very rare.  The rudder assembly keeper Chrysler employed was useless.  So if you capsized without taking additional precaution (tie a line to the rudder assembly) the likelihood of losing the rudder assembly was great.  Just this week I received another request for a rudder assembly want ad.  So I thought I would try to come up with instructions to build your own.  

The goal of this project is to provide all of the information you need to build a complete rudder assembly for under $200 with common tools and no special skills. In other words, a rudder assembly everyone can construct. I chose wood because, to me, it is the easiest and most forgiving medium to work with. Aluminum is the best material for the rudderhead no doubt as it is strong and maintenance free. However, cutting and drilling accurate holes in aluminum is a skill I don’t have – so wood it is. I have seen original Chrysler wood rudder assemblies still being used today. Not bad for 40 years old.

I have included lots of pictures because I am not the best at developing instructions that are easy to follow – the pictures hopefully will fill in the blanks.

The following is a list of materials you will need with sources and costs. The costs come in just under $200. Save more and in my opinion add strength by using white oak for the rudder cheeks. I believe white oak would be great for the rudder as well but I was not able to find a 12" wide x 40" piece required to form the rudder. I guesstimate the cost of the project would be $25-$30 cheaper using white oak all around. It was difficult placing a cost on expendable supplies (brushes, sandpaper, varnish) and I could be accused of juggling those costs so that the total project cost came in under $200 – guilty as charged!

Parts List

Wood

The Hardwood Store of North Carolina –

An alternative to mahogany rudder cheeks are white oak. White oak "feels" stronger than mahogany, not a soft I guess. I purchased 7.25 board feet of 4/4 (1/2" x 10.75") white oak for $21.39 from the Hardwood Store of NC which is enough for 4 rudderheads.

Hardware

Duckworks

Jamestown Distrubutors

Lowes Hardware

Varnish, brushes, sandpaper

Drawings:

1. Rudder Measurements PDF.
2. Cheeks.pdf

Tools List

• Electric drill, drill bits, ½" countersink bit
• Jig saw
• Belt sander (borrowed this from a friend)
• Accurate yard stick
• Combination square
• Hacksaw
• File
• Small wood plane
• Sanding blocks/sandpaper – 100, 150, 220 (I like the sanding block with a handle used for sheetrock
• X-Bench or equivalent (nice, but not required)
• Clamps, 2 each
• Screwdrivers, offset screwdriver
• 7/16 and ½ inch wrenches
• Drawing compass (a length of string will do)
• Sharp pencils
  

Tools for the Job

Instructions for building the rudder

1. Begin with the 9 ¾ x 40 mahogany board. Measure and mark the length 38 ½. Cut the board length to 38 ½ as marked. During all cutting operations I "leave the line". I then use sanding block to true.

2. Mark the Leading and Trailing edges with T and L so you know which is which.

3. Measure and mark 5" from the leading edge down the entire length of the board.

I used the combination square set to 5" to measure the 5" line.

This is not the mahogany board but rather a ¼ ply the same size. I used the ¼ ply to practice before letting loose on the mahogany.

4. Measure and mark 4" along the 5" line from the head end. The intersection of these lines is the location of the pivot hole.

5. Use a drawing compass set to 4", measure and mark a 4" radius from intersection above.

If you don't have a drawing compass a nail, string and a pencil will do the job. Tie the string to the nail and set the nail at the intersection of the lines found in step 4. Measure 4 inches of string and hold the string to the pencil to make the radius line.

6. Measure and mark 2 locations for the uphaul and downhaul holes, 1 ½" in from each side and ¾" below the 4" mark made in step 4.

7. Draw the curved sections for the leading and trailing edges by first measuring from the tip end to the head end from the 5" line drawn in step 3. Connect the measurements along both sides to form a curve. The measurements are listed in the Rudder Measurements PDF.

Using the combination square to measure the leading and trailing edges at one inch intervals. The ruler is set to 5 inches. Note: the first measurement from the tip is ½".

8. Cut out the head, leading and training edges with a jig saw. I cut along the line leaving the line on the board. I then use sandpaper to fine tune. Better to cut away too little than too much. So "leave the line".

9. Use a sanding block with 60 grit sandpaper to smooth the edges and take away the line.

10. Draw out the "flat" area on both sides of the board. First measure and draw a line across the board 8" from the head end. From this 8" line, draw a line 5" from the trailing edge and 3" from the leading edge. The length of the 5" line is 23 ½" and the length of the 3" line is 24 ½". Draw a curved line from the end of the 3" to the end of the 5" line.

I have my confidence up now as I am working with mahogany. You can see the 8" line running across the board.

If you look closely, you can see the lines of the No Sand zone.

11. On the leading edge, measure and mark 2 lines ⅛" in from each side, these are sanding guide lines.

Marking the leading edge

12. On the trailing edge, measure and mark 2 lines ¼" in from each side, these are sanding guide lines.

13. Draw the "no sand" zone on both sides of the rudder, leading edge 23 ½, trailing edge 24 ½ inches.

14. With a ½" drill bit, drill the pivot hole and the uphaul and downhaul holes.

15. With a 7/32" drill bit, drill holes for the uphaul and downhaul lines.

16. Use a belt sander (80 grit) to shape the rudder. Start with the leading edge. Start by placing the rear of the belt sander on the 3" line (3 inches from the leading edge). Sand with a smooth side to side motion from the 8" line near the top of the rudder to the tip of the rudder. Keep a constant eye on your goal, the top ⅛" line on the leading edge. When you get close to the line, switch to 120 grit. When you sand enough to just remove the line, flip the rudder over and shape the other side of the leading edge.

Shaping the leading edge

17. Shape the trailing edges with a belt sander. Same as the leading edge, except place the rear of the sander on the 5" line (5" from the trailing edge). And sand to the top ¼" line on the trailing edge. Remember to switch to 120 grit as you approach your goal. 80 grit leaves some fairly deep scars.

Shaping the trailing edge. I used foam to support the rudder as it took shape.

18. Shape the leading edge into a parabolic shape (front end of a submarine) with a flexible sanding block and 80 grit sandpaper. Finish shaping and smooth with 220 grit paper.

19. Finish smoothing and shaping the rudder with a sanding block and 150 grit, then 220 grit.

20. Use a damp cloth to remove a dust from the rudder, allow to fully dry.

21. Varnish the rudder with 3 coats of spar varnish (wait until the rudder cheeks and tiller are ready to varnish so all can be varnished at the same time). I started by varnishing the insides of the holes (pivot, uphaul, downhaul, uphaul line, downhaul line). I used a q-tip to do this job.

Ready to varnish

On to the main body. I used 2" sponge brushes to apply the varnish. Apply a light coat to avoid runs. Allow to dry at least 24 hours between coats. Sand lightly with 400 grit paper before applying the next coat. Be sure to wipe off all of the "dust" after sanding.

I considered painting the rudder with epoxy to add strength. I tested this by painting a scrap piece of mahogany with epoxy. I was disappointed to find the cured epoxy rough caused by lots of tiny bubbles. This is called "out-gassing". As the epoxy heats to cure, air is released from the wood and caught in the epoxy resulting in a rough surface.

Rudder, leading edge and trailing edge

That's it for the rudder! Next time we'll move on to the rudder head.

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