Home - Project Just Right
Chapter 1 - My goals and Requirements
Chapter 2 - Choosing the Boat to Build
Chapter 3 - Preliminaries, What I Did Before Starting
Chapter 4 - Setting up Frames and Building the Hull
Chapter 5 - Interior
Chapter 6 - Deck and Exterior
Chapter 7 - Topside Details
Chapter 8 - Keel, Centerboard, and Rudder
Chapter 9 - Mast, Rigging, Sails, Outboard & Anchors
Chapter 10 - The Electrical System
Chapter 11 - The Trailer and Trailering
Chapter 12 - Sea Trials and Cruising Pictures
Chapter 13 - Future Projects ... When is a Boat Finished?
Chapter 14 - Useful Information... Sources and Links
Chapter 15 - Questions and Answers
Chapter 16 - Other Vagabond Builders and Aficionados
Chapter 17 - A Few Good Ideas
Chapter 18 - Chapter 18 - Specifications and Equipment

Chapter 8 - The Keel, Centerboard, and Rudder

For about fifteen years, I have been saving lead in anticipation of building this boat. My friends have contributed everything from horse anchors to dental X ray covers. Its time to make a keel out of it.

Fabricating the Centerboard and Rudder

The centerboard and rudder blanks were cut from 1/2 inch plywood. I calculated the size of the 12 pound lead weight that were specified for the centerboard and cast the weights in a plaster mold. I routed out pockets in the centerboard blanks the size of the weights.

 

In the sea trials, I discovered that the centerboard floated in the case. The board was about 8 pounds lighter than the plans specified. The board needs to weigh 38 pounds and should just sink when immersed in saltwater. To add the extra weight, I used a hole saw and cut several holes in the centerboard. I poured the requisite amount of lead in the holes. I didn't notice any significant burning of the wood. I glassed over the holes and re-faired the board. This system for the centerboard works very well. The 2:1 purchase on the centerboard lanyard makes raising the board very easy. The weight of the board is enough to lower the board by gravity. The board has never hung up in the case.

 

The rudder and centerboard were glued up with epoxy with silica filler for a strong glue joint. I glued a HDPE bearing into the centerboard. The bearing was lapped to be a sloppy fit on the HDPE pin in the keel. The bearing was layered into the plywood panels as I assembled the centerboard.

 

I found a computer program on the internet that calculated NACA sections and used the program to make cardboard templates for the rudder and centerboard. After lots of planning, sanding and longboarding, I got the profiles to match fairly close. I applied two layers of DB120 fiberglass to the centerboard and one layer to the rudder. I filled, faired, flowcoated and primed the boards and then finish sanded. The centerboard was given two coats of ablative bottom paint. The rudder was painted above the waterline with topcoat, and below with bottom paint. Finally, the hardware was installed. I recycled an ash tiller left over from a previous boat.

   

These pictures show the finished rudder and tiller. The first picture shows the rudder in the locked up position. The second picture is a close up of the rudder head. The handle in the top is useful when raising the rudder or when attaching to the boat. The stainless rudder cheeks are 3/16 thick. I had to go to a thicker material to reduce the play between rudder and tiller. The last picture shows how the tiller folds down for storage. The rudder is attached with gudgeons on both the blade and the transom. A 1/2 inch solid stainless rod provides the pivot. When the rudder is in the up position, the draft is the same as the keel with the centerboard up.

 

I Almost Gave Up on the Steel Keel

The original design calls for a steel keel shell to be welded up. When I went around to various welders, none wee interested in the job. They thought it would be difficult to weld. I asked Jacques to draw up a full size template for the side plate for the keel in hopes that some welder would see it differently. Still no takers. Next, I discussed the possibility of making a cast fiberglass keel or a composite keel with Jacques. He responded with a preliminary design for a composite keel. It looked great. This design would have simplified the construction of the boat considerably in my opinion. Just as I was going to go forward, I found a welder who agreed to make the keel for me.

The Keel

I agreed to provide full size paper patterns for the keel to the welder. The keel bolt holes were drilled in the floors before I installed them in the boat. I was able to use my drill press and thus align the holes precisely (more or less). I took a bolt hole pattern off the hull. Patterns for the keel side plates were provided as part of the Vagabond plans. I made a wooden pattern to capture the curvature of the hull also. Since I had the CAD file for the keel, I also made up full size patterns for the top and bottom plates.

 

A friend arranged for a dozen aircraft quality bolts of a very special type. The bolt has a hex slot in the stem of the bolt so the bolt can be tightened from inside the boat using an allen wrench to hold the bolt while the hex nut is tightened. The bolt heads can be faired over since no access is needed. The bolts are an A286 stainless alloy and have a tensile strength of 15,000 pounds. The low profile heads will fit snugly in counterbores in the top plate.

 

The top and bottom keel plates are 3/8 inch and all other parts, 1/8 inch. I brought the top plate home to try it on the boat just to check for hole spacing. . It was an exact fit. When the keel was finished, I drove down to pick it up with my van. The interior was great but, the top plate warped a little. He prepared a HDPE pivot for the centerboard following the plans. The welder felt it was a difficult project but was still speaking to me, perhaps because I had my checkbook in hand and perhaps because he was finished. The keel shell weighs 170 pounds. I will need to add lead to bring it up to 550 pounds.

 

I cut a pattern for the centerboard from 1/4 inch plywood just to verify that the board would fit in the keel and trunk. The next pictures show the board up and down.

 

Fitting the Keel to the Boat

To counter the warped top plate of the keel, I built up a shim of wood and epoxy putty while the boat was upside down. I also fitted the bolts to make sure all the keel bolts slipped into place. During this process, I made a set of removable "training wheels" that fitted around the keel. By using the wheels and a floor jack, I was able to move the keel around and turn it over when necessary.

 

Filling the Keel

I decided to have the steel shell sandblasted before proceeding. I found an industrial coating company which did an outstanding job at a very reasonable price.

I thought about lots of ways to fill the keel with lead but finally settled on a small 10 pound furnace. I could melt small batches of lead, remove the slag, and pour directly into the keel cavities. I could control the balance of keel accurately. Previously, I weighed the hull and developed a spreadsheet which helped me calculate the required balance point for the keel. After the lead was in place, I completely coated the keel inside and out with epoxy. I filled the remaining portion of the keel cavities with expandable foam and added a layer of fiberglass over the top. I rolled the keel over and faired the keel with epoxy and microballoons and finally West 410 and resin. I long boarded and sanded the fairing and finally flow coated the finished keel with a final layer of epoxy resin. I let the resin cure, and after scrubbing, put on several coats of high build epoxy primer. After a final sanding, I applied several coats of ablative bottom paint.

If I had thought of it at this stage, I would have attached a sacrificial zinc to the keel. After three years of use including some beachings, I have a small hint of rust weeping through the paint. I purchased a zinc, now all I have to do is find a way to attach it.

 

Installing the Keel

The boat was jacked up on the cradle I built to hold the boat after turning right side up. I removed one side of the cradle and moved the keel assembly under the boat. I applied a thick layer of LifeCaulk polysulfide on the keel and bottom and gradually jacked and propped the keel until the keels bolts lined up. I inserted the bolts coated with caulk and tightened them up from the inside. Because of care I took earlier, the bolts fitted flawlessly.

The next problem was to get the boat onto the trailer. I gradually jacked the boat up out of the cradle with the transom braced against the back wall of the garage. I fitted a saw horse under the rea of the boat. I constructed another saw horse wide enough so that the trailer would slide through. By jacking and bracing, I gradually worked the trailer under the boat. Once in place, I lowered the boat onto the trailer.

 

John Hoaglund Builds the Composite Keel

 John Hoaglund decided to build the alternate composite keel for his scaled up Vagabond. He sent me these pictures and a write-up of the construction sequence.  

Basic Sequence of Assembly: 

  1. Fabricate centerboard
  2. Fabricate trunk
  3. Temporarily mount trunk on hull and tab structure together
  4. Remove assembly and apply internal structural fiberglass
  5. Fabricate plywood sheathing
  6. Assembly lower half of sheathing onto the keel
  7. Glass the lower half to keel, inside and out
  8. Add lead to the keel
  9. Assembly upper half of sheathing onto the keel
  10. Glass, fair and paint the outside of the keel

John's Impressions

Though the Vagabond is my first boat construction project, by the time I got to the keel, I felt pretty experienced in working with the fiberglass/epoxy. The entire keel project felt pretty familiar with regard to methods and techniques. As I finished glassing the inside of the keel, I was struck with how much strength Jacques had designed in. The fillets had up to four layers of 12oz biaxial glass. I soon concluded that some of Jacques' smaller boat designs have less fiberglass on them than I was going to use in just this keel. The ingot-and-drizzle method for loading the lead appeared to be a great success. I was worried about scorching the wood, or melting the epoxy, but there were no problems. The System-3 folks indicate that the epoxy would soften when the molten lead was poured over, but it would regain its full strength once it cooled. The only area where the drizzle technique cost me was when I still had some loose ingots afterwards and had to use a lot of epoxy to lock them in place afterwards. I have mixed feelings about my fiberglass pivot tube. I am having doubts about how well I can lock the pin in place with the cross-cut-and-screw technique. The jury is still out although I still feel that eliminating the metal in that area has some benefit.

The Centerboard  

These pictures show how I fabricated the centerboard. The centerboard is built in the same manner as with the steel keel, so this stuff isn't new to you. I did add the lead in a bit different manner. I bored five large holes all the way through the keel with a hole saw. I then used a smaller drill bit to rough-up the inside edges of these holes. This allows the lead to lock itself in place. I then placed aluminum foil over the back of the holes and laid down the CB on a pile of sand. The sand held the foil in place and "sealed" the back of the hole. I then melted and poured the required amount of lead into the holes. Straight epoxy was used to seal the lead and further lock it in place. I then faired the holes flush with the surface and wrapped everything with two layers of biaxial glass. The leading edge and bottom corner got an extra layer of glass for good measure. The final weight of my (scaled up) centerboard was 42 pounds.

 

 

The Trunk

These pictures show the centerboard trunk. It is much like the inside-the-hull portion of the steel keel trunk except that it goes deeper. Jacques has included new dimensions for the trunk in the PDF instructions for the keel. I did deviate slightly from his dimensions. Jacques new composite keel drawings don't show the location of the centerboard pivot point. I decided to derive the location from my CAD drawings of the original steel structure. When I did that, I noticed that the pivot wanted to be a bit further forward than a straight-fronted trunk box would allow. More due to stubborness than anything else, I created a small offset on the lower front edge to allow the pivot to be in the original location. I used 3/8" plywood for the sides of the trunk... this is a bit thinner than the specification. To make up for it, I applied two layers of 12oz glass to the insides of the trunk. This should add the strength and be a good wear surface. I used light 7oz regular weave cloth to line the inside edges of the box so that the entire inside would have a layer of glass. I also installed a bumper block to stop the board in the full-up position so that its bottom is flush with the slot.

 

 

At this point I installed my pivot tube. (No pictures, sorry!) I drilled clearance holes in the trunk sides to start. I then clamped the trunk together temporarily and placed the tube in position through these new holes. I then glassed the 1-piece tube in place. When the epoxy had cured, I reached a saw into the trunk and cut the tube down the middle to separate the two sides. It was easy then to trim down the excess tube on the insides, and blend the tube to the inner surface of the trunk. The fiberglass tube made this process pretty painless.

Since the inside of the trunk will be inaccessible once it is closed, I took the time to prime and paint the inside of the trunk before it was closed up. Once the trunk was closed, applied biaxial tapes across the outside edges of the trunk for strength.

The fun starts here. This is where I first assembly the different components that make up the keel's inner structure and the keel takes shape. Per an option recommended in Jacques' instructions, I decided to laminate the to two keel "plates" (top and bottom foil-shaped panels) out of layers of thinner plywood. I used two layers of 3/8" plywood for the top or "fairbody" plate and three layers of 3/8" on the bottom, giving me just a bit thicker plate -than required. I glued up the flat bottom plate right away, but the fairbody plate will need to be curved to fit the hull.

 

 

Before starting this process, I had already cut a clearance hole in the hull bottom for the trunk. I had also predrilled the six holes for the mounting bolts. Now, with the boat rolled over, I carefully leveled the hull fore-aft and side-side. I drew some reference lines on the hull to identify the centerline and laid one of the fairbody plates in place so that I could scribe the locations for the trunk and mounting bolts from underneath. I cut and drilled the holes in both pieces of plywood that will make up the fairbody plate. I then placed some protective plastic on the hull, placed the two plywood pieces in place and laminated them together. I used temporary bolts through the holes to aid in alignment and I loaded lead on top to hold the pieces to the hull's curve.

The next step was to temporarily mount the trunk into the hull. I held it in place with various clamps and scrap wood. The bottom edge of the trunk was set level. I decided to extend the depth of the keel 1" deeper than specified. There was some concern that the keel might not have enough internal volume to hold the lead required to reach the specified weight. This 1" extension gives me a bit more room inside for lead. (This was later proven not to be a problem. The original depth should have plenty of room.) I buttered in some wood-flour filled epoxy between the fairbody plate and the trunk to hold these together.

At this point Jacques suggests applying the longitudinal stringers, then removing the assembly from the boat and working on it separately. I chose to tack together all of framework while still in place on the hull. I felt that this gave me the best chance of keeping the fairbody plate curve from shifting once I removed it from the hull. I added the various transverse frames and the bottom plate. I did not tape the pieces at this time, I used only wood-flour filled epoxy paste to hold the pieces together. Once the epoxy had cured, I removed the clamps on the trunk and removed the assembly down to some saw horses. Note: The position of the keel bolts corresponding to the "D" bulkhead are very close to where Jacques' has specified one set of frames. I checked with him and he allowed me to offset these frames slightly forward for better clearance.

These pictures show the keel removed from the hull. I am using stainless threaded rod for my keel bolts. I have them temporarily in place for these pictures.

 

At this point I prepared the plywood sheathing panels. These are made of 1/4" plywood. I started with a paper template of the shape and transferred the shape to the plywood pieces. I was concerned that the plywood would have difficulty forming the tight radius at the front of the keel. My solution was to thin down the plywood in that area. The first picture shows the front edges of the two plywood showing lines where I removed layers from the plywood with my belt sander. The next picture shows how I added a narrow strip of 12oz biaxial across the gap to join the two pieces together. The third picture jumps ahead a little bit and shows the sheathing after I applied it to the hull. You can see how the front curve came out. The last picture is another view of the sheathing on the keel.

 

With the sheathing prepared and set aside, I got started glassing structural fillets to the inside of the keel assembly. There is a LOT of fiberglass in here. The seams that lap onto the fairbody plate have four layers. The seams on the bottom plate have three layers and the vertical seams all have two layers. All tape edges are staggered to avoid stress concentrations. I chose to apply the tapes wet on wet. I first precut all of the tapes required. I formed wood flour fillets on all of the seams. I then pre-wet the tapes on a bench covered with plastic and applied them. Once the epoxy had cured, I trimmed the protruding ends of the fiberglass and then flipped the keel and did the same thing on the other side. These pictures show the progression. 

 

In these pictures you can see the fiberglass tube that I created for the centerboard pivot rod. I decided to make a tube out of fiberglass rather than installing a steel tube inside the keel. I started with the pivot pin, wrapped it in two layers of waxed paper, and then wrapped it with several layers of epoxy saturated biaxial cloth. Once it was cured, I tapped the rod out with a hammer and peeled the wax paper out as best I could. The idea of using a fiberglass tube appealed to me since it would be easy to bond the tube into the wood-epoxy-fiberglass keel assembly. It also eliminates a piece of metal under water, a potential rust/corrosion problem. I have had a bit of trouble with it, however. During some early sea trials, I discovered that the centerboard pivot pin was moving inside the tube. I think this may be due to some of the waxed paper remaining in the bore. When I clamped the pin in place with the expansion screw, it lost tension when the waxed paper dissolved. In any case, if I were to do this again, I would still make the fiberglass tube, but I would try to incorporate some other method for locking in the pin, perhaps a glassed-in captive nut that would catch a diagonal screw through the end of the pivot pin.  

Rather than mess with this issue any further during the next few sailing seasons, I've actually glassed the pin in place with a small circle of fiberglass over the ends of the tube, locking the pin in place. The next time I need to service the board, I'll have to sand through the glass to remove the pin. Perhaps by then I'll have decided on a better solution. 

The next step is to apply a portion of the external sheathing to the keel. By applying the lower half of the sheathing first, you create more of a "bucket" shape to hold the lead. It also allows you to apply fillets and glass on the inside of the sheathing on the bottom, giving extra strength in the area bearing the weight of the lead. Pictures 32 to 35 show the lower portion of the sheathing being glassed on. By the way, I applied the entire sheathing first and then cut off the upper portion after the epoxy putty cured. I did this so that the lower portion of the sheathing would take the most natural curve. If I had attempted to apply the lower portion alone, I was afraid it might not meet smoothly with the upper portion later. My method seemed to work pretty well. Note also that I did not attempt to split the front section of the sheathing. Getting the front to curve properly took me a lot of work as it was. I didn't want to complicate it any more. My method also allowed me to build fiberglass fillets around all internal joints at the front of keel, making it as strong as possible.

 

 

The keel is now ready for the lead to be loaded in. I weighed the keel and calculated how much lead would be required to get the final weight. This picture shows the keel with the pile of lead that will be loaded in. You can also see a bit of how I did my keel bolts. I bedded stainless load-spreading plates at each hole location as described by Jacques. At the end of my threaded rod, I jammed two nuts together using Lok-tite. The lower of the nuts was a stainless wing-nut. I figured that the wing nut would prevent it from turning.

To get the lead into the keel I first angled the keel up to about 45 degrees and loaded in as many of the lead "cup cake" ingots as would easily fit into the chambers. We took the rest of lead, melted it, and drizzled it in over the ingots. Once one side was done, we rolled the keel over and repeated the process on the other side with the remaining lead. As recommended, we tried to fill the front chambers first.  

The first picture shows one side with the lead installed. In order to make sure the lead was firmly locked in place, I poured phenolic-filled epoxy over everything, as shown in the next picture. I did this because a few of my "cup cakes" weren't firmly locked in place. This extra step made sure that they could never move inside the keel.

   

In this picture, I am reinstalling the upper half of the sheathing. It was tricky to get the curve of the front to match, but I got pretty close with some wire-ties, clamps and battens.

 

In this picture, I have already taped the edges of the keel and I've poured foam into some access holes I drilled. I drilled several large holes near the top of each chamber. The last picture shows the keel once I trimmed the excess foam.

   

In this picture I am adding the fiberglass around the inside seam where the trunk opens through the bottom of the keel. I radiused the edge of this opening as described in Jacques' instructions and applied two layers of light fiberglass to the edge. It was a challenge to sand the edge of this new glass on the inside of the trunk. By the way, if you pre-paint the inside of the trunk with bottom paint before closing it like I did, make sure you leave the bottom 3 or 4 inches unpainted. I had to remove the bottom paint along the bottom edge.

 

Finally, the keel completely glassed and faired, and I'm doing a trial fit of the centerboard.

I suspended the keel for painting on some 2x4's using some brackets and lots of strong screws. I would recommend using 2x6's instead as the 2x4's bent alarmingly. In these pictures, you can see the keel and the centerboard with their first coats of underwater primer.

   

The only remaining steps were the installation of the keel onto the boat and painting everything up with bottom paint. The inside portion of the trunk was glassed into the hull with fiberglass fillets, making the assembly a permanent part of the boat.

Thanks to John Hoaglund for providing these informative pictures and detailed description of the process. Nice job John.

Yet One More Keel

The Vagabond has three choices for keels: The steel keel centerboard, the composite keel centerboard, and a full depth steel keel. The boat Nasu, built in Finland, use the steel keel. This is a picture of the keel. From the picture, it looks like those Finns know how to weld. The deep keel can be built with less weight and uses only three floors (transverse frames which carry the keel bolts) instead of the five that the steel keel/centerboard requires. I expect the deep keel boat could be a real flyer!

 

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