Keel refurbishing

Feb 11, 2015
212
Catalina 22 Lake Jacomo
I will be removing my swing keel soon in preparation for refinishing. I have a plan for the safe removal and re-installation, but hadn’t really planned to do anything more than a basic strip, fair and reseal to the keel itself. I was recently reading $tingy’s blog about his keel refurbishment and he mentions the castings being flatter on one side and the performance issues it can cause. This made a lot of sense to me as my boat has always sailed better on a port tack than on starboard. On mine, the Mexico side is noticeably smoother with a fairly consistent shape whereas the other side is rough and inconsistent. So I’m now giving more thought to profiling to the recommended 13% NACA foil shape. I’d really like to hear from anyone who has done the foil profiling and what you felt about the performance before and after. Do you think the extra time and expense was was worth it vs merely fairing smooth the original shape? Would you do it again? Also, did you use the CD template which $tingy claims actually produces a 16.5% foil or did you profile to a true 13%. Bonus points if you have done both and can shed some light on any notable differences.
 
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Likes: Grotto
Jul 13, 2015
893
Catalina 22 #2552 2252 Kennewick, WA

Page 2 of the thread above -- I grabbed design foil (free download/trial) which will output any NACA you please and the bonus part is that it exports to a printer at scale. literally printed to paper-- laminated it with packing tape and transferred to plywood.

link here:


Worth it? Probably not-- (assuming your keel isn't complete crap to begin with), but the way I justified it: I'm only doing this once! get it all and move on.

All my decent pictures here including the printed foil and template:

 

Grotto

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Feb 18, 2018
273
Catalina 22 Wilmington
I will be removing my swing keel soon in preparation for refinishing. I have a plan for the safe removal and re-installation, but hadn’t really planned to do anything more than a basic strip, fair and reseal to the keel itself. I was recently reading $tingy’s blog about his keel refurbishment and he mentions the castings being flatter on one side and the performance issues it can cause. This made a lot of sense to me as my boat has always sailed better on a port tack than on starboard. On mine, the Mexico side is noticeably smoother with a fairly consistent shape whereas the other side is rough and inconsistent. So I’m now giving more thought to profiling to the recommended 13% NACA foil shape. I’d really like to hear from anyone who has done the foil profiling and what you felt about the performance before and after. Do you think the extra time and expense was was worth it vs merely fairing smooth the original shape? Would you do it again? Also, did you use the CD template which $tingy claims actually produces a 16.5% foil or did you profile to a true 13%. Bonus points if you have done both and can shed some light on any notable differences.
I used stingy’s template and yes one side is indeed flatter. Top 1/3 on port is almost completely flat on my keel. The other side is not as extreme. It threw me as I did the starboard side first and thought I had bought too much filler. Used the whole gallon by the end

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