Refinish your swing keel for best performance

[$tingy Sailor]

It's been a very swinging winter on this forum with lots of swing keel refurbishments going on.

If you haven't had your fill of refinishing yet, you might be interested in the 5-part series of posts titled Refinish your swing keel for best performance that I started publishing this weekend on my blog at stingysailor.com. They're part of celebrating all things swing keel during my Spring Swing Keel-a-Thon.

No, that's not me and the first mate, in case you're wondering

I've tipped my hand a few times so far in other posts here, but this series lays it all out from start to finish with lots of pictures, including a time-lapse slideshow of the fairing build-up! Part 1 kicks off the series with removing the keel using a sled based on the plans in the Catalina Direct Swing Keel Refinishing DVD. If you have a different trailer than the Trail Rite that probably was original equipment with your sailboat, this post might be of special interest to you. I have a Calkins trailer that required some workarounds.

Here's the BEFORE shot. If it looks like the keel was nearly flat, it was.

Besides the 5-part series, I have two other posts related to swing keels that I'll either throw in along the way or shorter after. While you're there, be sure to read last week's post, Five swing keel maintenance blunders and how to prevent them. It includes the open letter from Lowell Richardson in 2013 about a C-25 that sank on her mooring after the keel cable broke.

In the coming weeks, I'll update this thread with highlights from the latest post but the best way to stay updated and to get the whole story is to subscribe to the blog. If you can imagine yourself ever doing this project, be sure you don't miss the special post, The error in a popular DIY DVD that will slow down your C-22,where I prove mathematically that the CD template is almost 4 NACA percentage points too fat due to assuming the wrong keel hanging angle. If you already used the template, uh... you wound up with a pretty keel! Yeah, that's it.

If anybody has questions about the project, for example, compared to the methods used by other owners, feel free to comment here and we can have a separate discussion.

Enjoy!

 

[$tingy Sailor]

The second installment posted this morning, Refinish your swing keel for best performance – Part 2: Cleaning.

This week, I describe using hand tools and power tools to remove most of the old coatings and rust, one way to lift and move the keel so you can work on it elsewhere, and the different methods of removing the remaining rust either chemically or by sandblasting to prepare it for fairing.

I also show examples of keel defects commonly found on C-22 swing keels, including mine. Check it out. Your keel might be one of them.

 

[Jackdaw]

Those pictures are mind-blowing. That's a hell of a blog you got.

 

[Leeward Rail]

Those pictures are mind-blowing. That's a hell of a blog you got.

I second that.

I'll be following with interest. It's one of the first things I've been thinking about as a possible project.

 

[$tingy Sailor]

The third installment posted this morning, Refinish your swing keel for best performance – Part 3: Fairing. This is the heart of the project and half way through.

I start with a bare sandblasted keel and describe common keel defects, the fairing system I used, how to seal a freshly sandblasted keel, applying body filler to build up an accurate hydrodynamic foil shape, and paying extra attention to the leading edge of the keel.

There's even a cool time-lapse photography slideshow of the entire fairing process on one side of the keel. It's like a video but faster and it helps to visualize the progression of the build-up.

This is the most tedious and time-consuming part of the project but where diligence pays off in the long run.

 

[CaptDon01]

I thought it would be interesting to compare the new design keel foil. If I ever pull the trigger and order one, I'll have to see what foil spec's the factory uses. Unlike the original cast iron keels cast in Mexico, they actually have a quality control process.

Don

 

[$tingy Sailor]

Good point, Don. If you can get the max. thickness and keel width, you can calculate the foil % from that.

 

[Leeward Rail]

I thought it would be interesting to compare the new design keel foil. If I ever pull the trigger and order one, I'll have to see what foil spec's the factory uses. Unlike the original cast iron keels cast in Mexico, they actually have a quality control process.

Don

Ok... rookie question:
When you say "new design", are you saying that the later "new design" mk1 models had keels built differently ?

I understood that a stainless steel+lead+fiberglass keel is available, and that they were on the mark 2.

 

[CaptDon01]

Ok... rookie question:
When you say "new design", are you saying that the later "new design" mk1 models had keels built differently ?

I understood that a stainless steel+lead+fiberglass keel is available, and that they were on the mark 2.

After ~15 years, and thousands of the original C-22 versions were built, Catalina Yachts updated the popular family sailboat for model year 1986. These are often referred to as the "New Design",(originally only available in fix, or swing keel, later in the production run, a wing keel was offered). These used the same cast iron swing keels that Catalina Yachts used on the first C-22 versions, and were produced until 1994. With the model year 1995, Catalina Yachts introduced the Catalina-22 MK-II. These also included the newly designed swing keel that replaced the cast iron swing keels,(available with wing keels and fin keels also). These new swing keels have a stainless steel support, use lead for ballast, and are encased in a fiberglass shell. They are the only keel available on the C-22 Sport, which is now, the only Catalina-22 built since they discontinued the MK-II versions. There was no C-22's designated as the MK-1.

I understand the swing keels are interchangeable between all the model years, with the exception of the very first few early production C-22's.

Hope that helps....

Don

 

[CaptDon01]

Ken,

I wrote Dennis Slaton an e:mail questioning him about his thoughts on swing keels. Dennis is a past C-22 National Champion, and builds some of the best racing C-22's. Here is his opinion on C-22 swing keels:

"The problem with the C-22 keels are how much they vary. I have faired them
every way possible using many different templates. The main problem is the
cord length and the cast iron material used to make them. Most C-22 keels
are asymmetrical and too thick for their cord length, leaving only two
choices, increase the cord length ( which the class does not permit) or
remove material ( which practically speaking is impossible) to make the keel
thinner. What I have done to my keel is to keep it as thin as possible and
make it symmetrical. I used 2 or 3 simple templates made from the fat side
to use on the flat side and a straightedge to use on the vertical. I saw a
guy with his keel in my shop, work on his keel for 2 weeks, changed the cord
length and got the NACA shape he desired. I told him from the beginning he
wouldn't have better boat speed and he didn't . At the end of the day I will
always trade more lift for less drag. More lift does make the boat easier to
sail upwind, but if you can steer a fine groove the thin keel will go thru
the water faster. But when you head down the hill more lift is not what you
want, less drag is your friend. From what I have seen the Sport's with they're
new thicker keel have the same quality problems as the old boats. The only
competitive Sport I have raced against was Rob Fowler form Chattanooga.

Rob reworked everything about the keel from it shape to the way the keel was
hanging to get it competitive and he still got killed down the hill. So NO, I
don't want a Sport keel, thanks but no thanks. Older boats have a somewhat
well known advantage in racing, due in most part to the thinner and lighter
keels they came with from the factory."

Dennis didn't mention his NACA keel foil percentage, maybe that's his personal winning secret.

Thought Dennis's thoughts were interesting. If there is anyone who knows how to make a C-22 fast, it's Dennis.

I would invite those that want to see some competitive boats to attend a local C-22 Regatta, and the C-22 National Regatta will be up in Portland, OR this summer. We might not all be racers, but we can all learn a few tricks to improve the performance of our C-22's.

Don

 

[Leeward Rail]

Don,

New design boat vs new design keel... check.

I thought as much but I thought I'd ask.

Cheers !

 

[CaptDon01]

Yeah, I should've said "versions", of which they manufactured 4.....

Don

 

[$tingy Sailor]

I appreciate Dennis's comments. He's who I contacted about the class rule interpretation related to refinishing that I put in the next installment in the series.

And his comment about the factory keel being too fat at the bottom is one of the problems I recognized almost immediately. It's over an inch too fat at 19% of the chord length and the only way to fix it would be to grind it off. Catalina Yachts would have done us all a favor if they would have just made both sides almost flat all the way down.

I'm looking forward to seeing how my boat points with the new keel shape. She had a definite limp before.

 

[$tingy Sailor]

This week's installment in the Spring Swing Keel-a-Thon is The error in a popular DIY DVD that will slow down your C-22.



If you want to refinish your C-22 swing keel correctly, you might be planning on buying the Swing Keel Refinishing DVD from a certain Catalina parts dealership. It’s been around for over 15 years and is the de facto authority on how to do the job.

But if you use the template that’s included with the DVD to fair your keel, it will prevent you from getting the best performance out of your keel.



This blog post is a detailed analysis of the template, the geometry of the C-22 swing keel, and the undesirable results the template produces when used to fair the keel during refinishing.

If you want to get the most bang for your hard-earned bucks, sweat, and hours of labor, you owe it to yourself to read this post to avoid disappointing results.

 

[Gene Neill]

" From what I have seen the Sport's with they're
new thicker keel have the same quality problems as the old boats."

Hmmmm, Don, do you know what he meant by "quality problems"? I wonder if he meant to say "design problems"? Obviously Sport keels can't rust, so ...?

I'm in the class of people who don't care much about a tenth of a knot (if the difference is even that much) due to a design imperfection, but I'd hate to someday break open the piggy bank for one of those fancy Sport keels and have "quality" issues with it!

 

[CaptDon01]

Gene,

Yes, Dennis was referring to the thickness of foil on the fiberglass swing keels. More lift for going to windward, but makes it slow on the run. And Dennis is a racer. So he would rather fight to keep a thinner keel in the groove going to windward, and reap the benefits of the slimmer keel foil downwind.

And I know someone is going to ask, no you can't raise the keel when going downwind according to the C-22 Class Rules.

 

[$tingy Sailor]

This week's installment in the Spring Swing Keel-a-Thon is Refinish your swing keel for best performance – Part 4: Sealing and painting.



In that post I describe: building a fiberglass reinforced guard on the leading edge, applying the final waterproofing coats of epoxy, bonding centering spacers on the upper end, priming with a barrier coat of epoxy paint, and applying ablative bottom paint last.



Next week, I'll wrap up this series with some installation tips.

 

[$tingy Sailor]

The Spring Swing Keel-a-Thon on The $tingy Sailor winds down this week with the last post in the series. It's titled Refinish your swing keel for best performance – Part 5: Installing.



This week, I describe: how to prepare the hull, three manufacturing defects in the keel hanger hardware to watch out for, tips for keeping the keel centered in the trunk, the proper method to tighten the hanger bolts, and end with a materials list and a brief project cost analysis.



Remember! If you haven't subscribed to the blog yet, do so this week and you'll receive a link to my free keel fairing template when I send the next newsletter by email. Each newsletter contains extra info, special offers, or notifications of stingy gear deals for subscribers only. Its free and you can unsubscribe at any time.

Next week on the blog, I'll shift focus away from the keel and to an inexpensive upgrade that can add modern convenience to your cruising.