Refinish Your Swing Keel for Best Performance – Part 1: Removing

Does your swing keel look like it has leprosy? Does it make a disturbing klunking sound when you switch tacks? If it has exposed rust, do you know for a fact how extensive it is? Would you be surprised to learn that the swing keels of many older C-22s are not properly shaped to minimize drag and have major casting defects under the paint? Want to learn how to refinish a metal swing keel for best performance and the lowest cost? And by best performance, I mean speed, pointing ability, and durability. If you can answer yes to any of these questions, you need to read on.

This post is the first in a five-part series on how I restored the iron swing keel of my 1981 Catalina 22. This post describes how I removed the keel to work on it, including methods I had to improvise to accommodate my Calkins trailer.

Subsequent posts in the coming weeks include:

Part 2: Cleaning
Part 3: Fairing
Part 4: Sealing and painting
Part 5: Installing

I purchased the Swing Keel Refinishing DVD from a certain Catalina parts dealership to guide me through this project. In this post series, I won’t repeat all the info provided with the DVD since that would take too long, but in Part 3: Fairing, I do point out two serious mistakes that affect the included template that you can use to shape your keel. The DVD gives some useful tips and demonstrates the most important steps, however.

Instead, I describe the basic steps that I took, the deviations from the DVD that I made, some tips you won’t find on the DVD, and the particular conditions that I discovered with my keel that you might also find with yours. That should give you a good feel for whether you want to buy a copy of the DVD and do this project yourself. The job can definitely be done without the DVD using the information here and available elsewhere on the web.

If you decide to do this project yourself, do it safely. The weight of the keel falling on any part of your body can cause serious injury. The debris from grinding paint and sanding fillers is toxic to breathe and can damage your eyesight. Fumes from the fillers, paints, epoxy, and cleaners are dangerous to breath. Take all appropriate precautions and wear safety equipment. You use the information presented here at your own risk.

What you can’t see can cost you

When we purchased Summer Dance, the bottom paint had been re-applied the year before. It looked in good shape on the surface—no signs of major flaking or wear—including on the keel. I didn’t expect it would need any work for some time. But after a few launches, I began to notice small patches of paint falling off the hull and keel. It had an obvious adhesion problem.

It was starting to look pretty noticeable when Summer Dance got beat up in a freak summer storm. Even though nothing solid hit the underbody or the keel, when I pulled her out of the water, the beating against the dock must have reverberated throughout the hull because significant patches of bottom paint had flaked off.

I was fortunate that the insurance settlement for the entire damage from that storm included a new bottom paint job for the hull. But it wasn’t enough to refinish the 525 lb. cast iron keel, I had to do that myself. I wasn’t looking forward to it, but I did want the keel properly shaped, sealed, and painted.

Improvise only if you must

At the start of this past winter, I removed the keel to begin the restoration process but I didn’t follow the Swing Keel Refinishing DVD very closely. It shows how to remove the keel when the boat is sitting on the Trail Rite trailer that originally came with the boat from Catalina Yachts. The DVD includes plans for building a sled to hold the keel upright so that you can roll the keel out from under the boat to work on it. The Trail Rite trailer has only the axle and a single, small cross brace to maneuver around.

I replaced that trailer with a Calkins trailer that is very different. Besides the axle, it has large cross braces in front and behind it with floating roller assemblies underneath. The boat also sits higher on the Calkins than on a Trail Rite trailer. That meant that I had to build my keel sled taller than shown in the plans and I couldn’t “shuffle” the sled under the axle like shown on the DVD. Other than that, the process shown on the DVD works fine. You’ll undoubtedly need to make slight adjustments for your boat, your workspace, and the tools and materials you use.

Tools and materials for removing a swing keel
Tools and materials for removing a swing keel from top clockwise: a variety of 2x and 4×4 lumber blocks, homemade sled with PVC rollers, heavy duty nylon strap, come-along, hydraulic floor jack.

By the way, I can personally vouch for the need for hardwood or oversize uprights and metal cross-bracing between them as shown on the plans. At first, I used softwood 1×4 lumber with several deck screws in each upright and no cross-bracing. Then while rolling the keel onto the sled, the keel tipped slightly and split one of the uprights completely, which almost caused the keel to fall off the sled. I replaced them with 2×4 lumber and metal strap cross-braces, which worked well for the rest of the project.

BEFORE - Flaking and rust starting to show. Note the lack of space for the sled underneath.
BEFORE – Flaking and rust starting to show. Note the lack of space for the sled underneath.

Like unloading bombs from an F-18, only different

The removal went pretty smoothly, actually, even single-handed. I started by raising the four corners of the trailer up onto jack stands to make a stable platform. With the keel lowered onto the rear trailer rollers, I disconnected the keel winch cable. Then I placed a hydraulic jack under the other end of the keel, removed the keel hanger brackets, and lowered the front of the keel to rest on the front trailer rollers. The keel was completely separated from the hull at that point and resting entirely on the trailer.

Next, I alternately jacked the ends of the boat up a couple of inches at a time so that I could place 2×8 wood blocks between the hull and the bunk boards over each bunk post. While I did this, the keel side rollers and guides built into the trailer held the keel close to vertical with the help of a few lengths of 2×8 lumber as shims.

On the C-22, the best place to jack up the hull is directly in front of and behind the keel slot where the hull is stiffest. A length of 4×4 lumber between the jack and hull with a padded block on top works well.

Be sure to keep the weight of the hull evenly distributed between at least three points on the hull at all times. Keep everything level and plumb. Go slowly, double-check everything, and watch for shifting.

With the keel detached, the boat is about a quarter lighter. After a few blocks were stacked over each bunk, I had enough clearance for the keel to pass aft through the trunk slot in the hull.

Instead of shuffling the sled under the trailer like shown on the DVD, I had to shuffle the sled behind the trailer with the keel partially removed. I used a come-along attached to a nylon strap looped around the forward end of the keel to roll it backward off the rear rollers and onto the adjacent sled.

With the bottom end of the keel on the forward end of the sled, I pulled them both until the top end of the keel was all that was left on the rollers. Then I jacked up the bottom end of the keel slightly off the sled so that I could roll the empty sled forward and lower the bottom end onto the rear end of the sled. One last short pull and the top end of the keel rolled onto the front end of the sled. It was then relatively easy to roll the sled around by myself on PVC pipes Egyptian pyramid-style to where I could start the real work.

What to do while you’re waiting for the keel to dry

It’s okay to leave the boat blocked up on the trailer while you work on the keel so long as the blocks aren’t causing oil-canning. That’s what happens when the blocks are located at a weaker spot in the hull and the fiberglass deflects inward from the pressure like the bottom of an old-fashioned squeeze type oil can. It’s not a good idea to work on deck or in the cabin while it’s blocked up as the hull or the blocks can shift from your weight moving around, so set the hull back on the bunks if you expect to work much topside.

After you have the keel removed is also a good time to do any repairs or replacements of the:

  • Keel pivot assembly (pivot pin, hanger brackets, bracket bolts, weldments)
  • Lifting hardware (winch, cable, turning ball, eye bolt)
  • Locking assembly (lock bolt, weldment)
  • Keel slot and trunk (this is a good time to clean and paint them without the keel in the way)

I describe refurbishing and replacing some of these parts on Summer Dance at the end of this series.

With the keel fully and easily accessible, I began the cleanup phase, which continues next week in Refinish your swing keel for best performance – Part 2: Cleaning. In that post, I describe using hand tools and power tools to remove the majority of the old coatings and rust, one way to lift and move the keel so it can be worked on elsewhere, and the different methods of removing the remaining rust either chemically or by sandblasting.

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15 Comments Add yours

  1. James McPherson says:

    A lot of good info here. My trailer is a non standard custom homemade job from a mac 25 rebuild. I believe I will have to take the trailer out from under the boat in order to drop the keel straight down to the sled. This is how I dropped the keel on the Mac 25 and on a Southcoast 23 before.
    This does make me rethink my trailers keel support rollers. I have 2 one at midpoint one at aft end. I did not put one under the hangers, thinking the other two with the cable slack would take the weight? your opinion please.

    1. Hi, James

      If you have the stands or whatever to pull the trailer out first, it definitely makes removing an easier, faster job.

      The picture you see in this post is before I moved the boat forward on the bunks about 6″ to get more weight on the tongue. Now the very end of the keel rests on the rear roller and the forward rollers support the middle of the keel. That works well in my case. If I had another roller at the front of the keel, it would probably be too low to do any good anyway. I’d say you’re good as-is.

      Good luck on your keel project. Hope to see you around for the rest of the series. Questions and comments are always welcome.

  2. Curtis from Alaska says:

    Good write up. I am having to do some fiberglass repairs to the exterior of the keel slot and trunk. I wanted to also repalce the bunk boards at that time. How does one remove the boat from off the trailer to do that? Do you have any thoughts on this? Perhaps James M. has thoughts since he has done this before.

    1. I replied to your question over on the “Trailer bunk board replacement” post.

  3. Barry says:

    Where is the link to the pdf for the fairing template.

    1. Hi, Barry

      The template will be available for download at the end of the series in two weeks but only to subscribers. To receive the link, subscribe to this blog for free by clicking the Follow button in the sidebar on the right and entering your email address. You will then receive my newsletter by email that contains bonus information, late breaking news, special offers, and other opportunities just for subscribers as my thanks for following this blog. If you want to stop receiving the newsletter at any time, you can cancel your subscription by using the link at the bottom of the email.

      Thanks for reading and I hope you’ll stay around.

  4. Dave says:

    Thanks for the description. My marina has a rolling lift that would make the keel removal easier, but . . . . Will the boat float okay without the keel, mast up, while I do keel refurbishment?

    1. Hi, Dave

      I’m not sure. The keel is only a quarter of its entire weight so most of the remainder would be above the waterline after you remove the keel. Without the lower center of gravity, she would probably list to the heavier side, maybe considerably so depending on what’s inside. If your slip isn’t well protected from wave action, it could rock around a lot too and possibly take on some water. I doubt it would capsize so long as your cockpit drains are clear and everything else closed up, but the listing could make it difficult to right her and pull her out again. You could try it and see, but I’d recommend putting her on a trailer or in stands while you do the work. That would also give you access to do any repairs and bottom painting at the same time.

      Thanks for your question and let us know how it turns out!

      1. Joseph Langford says:

        My 1971 C-22 has been without its keel for months at the dock. It floats fine. I have also motored it in calm seas, close to shore without any issues. I would not try to sail it. I will be following the instructions here to recondition my keel and get it back on the boat.

  5. Chris James says:

    1983 Macgregor 22 owner – I am having difficulty visualing the keel lowering and disconnection process (visual learner…). Did you take additional photos of the removal process which can be shared? Should I purchase the DVD from the Cat manufacturer instead?

    1. Sorry, Chris, I did not. I did it inside my barn where the lighting wasn’t great, I did it by myself, and I didn’t want to take the time to take photos. It was the first time removing the keel with this trailer, which is different than the stock trailer. So there was a fair bit of trial and error involved and taking good photos would have taken more time than the job at hand. In retrospect, I probably should have planned the job better so that I could have taken photos.

      It might help you to imagine the keel as just a big, long weight held up at each end. First, you lower the aft end down onto the cradle with the winch and disconnect it from the keel. Then place a jack under the front end and remove the hanger bolts. Then lower the front end onto the cradle and roll the cradle out from under the boat. The rest of the process is just what you need to do to make those steps possible: make the cradle to hold the keel vertical, raise the boat on the trailer for room to remove the keel, etc.

      I hope that helps. If not, let me know and I’ll try to find a better resource for you. The CD video doesn’t show a lot of detail about the process either.
      $tingy

  6. giampaolo torresi says:

    Hi, for the first i want say thanks for sharing your experience. I found the article very interesting. I’m owner of one beneteau first class 8 that seem have exactly the same rudder profile. I’m interested to build template to put in shape the rudder, can you help me to draw the right shape for that? Best regards

    1. Hello, Giampaolo

      If you are indeed referring to your rudder and not your keel, then you should not need to modify the shape at all, just refinish it, if necessary.

      If you meant your keel instead, then you can plot and print any NACA foil shape at Airfoil Tools. After you print it out on paper, transfer the curve to a more rigid material like cardboard or thin plywood and cut it out to make your working template.

      1. giampaolo torresi says:

        Thanks so much for your quick reply, actually I’m restoring keel and rudder and i would understand what can be best airfoil to apply. Soon as possible i want measure inclination but maybe for the keel it’s around 15° like in your case. In this case NACA 0019 it’s the best shape?

      2. Your keel looks to be around 30 degrees, but measure it to be sure. You want the effective foil shape through the water (not the perpendicular cross section) to be about 13 percent. For a C-22, this is a NACA 0015 foil. Yours will probably be close to the same, depending on your rotation angle.

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