Dropping and Re-Hanging Cast Iron Stub and Swing Keel

Started by Spot, May 31, 2023, 09:59 PM

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Hello Friends,
My Luger Southwind 21 has a 400# external keel stub and swing keel. I just finished epoxying in the new framing and want to drop the stub, re-bed, and re-hang the arrangement with new stainless hardware.

I could hire the boatyard to do that but I am afraid that a short haul and a couple hours yard worker time could be 500 or more dollars. I'd rather spend that money on...well, another boat :)

I saw a couple videos where a gentleman jacked up a boat and removed the trailer and removed his keel.

Anyone done this maneuver? Which bedding compound? Best way to loosen up whatever adhesive/sealant is already there? is already there?

I have been looking at lower end, 28-52" x 2500 lb pipe stands, I could get 3 or 4 of those for less than 300$ and be set the next boat off trailer experience. My boat all up is around 2000# so not pushing it in that regard.

I still have about a week until full epoxy cure, will not mess with the hull until then.
Big dreams, small boats...

Wayne Howard

Calling Charles Brennan. Charles Brennan to the white courtesy phone!
Wayne Howard
Master and Commander of S/V Impetuous
I'm not a complete idiot, some parts are missing.

Charles Brennan

Wayne, and Spot,
Yes, I saw the post but can not do very much about it since the web site is clogged with pics (of which I am probably the most guilty) and therefore, I can not provide a photo essay of pulling my trailer out from underneath my boat.
Ditto with my 2015 keel refurbishment, since it is frozen somewhere in the old TSBB archives. (Although, I do have the original pics and could post them once the web site gets humming along again.)
Not hard, but maybe not for the Faint of heart, either!  ;D

Hope this clarifies,
Charles Brennan


Thanks Wayne, thanks CB.
All of the cast iron is outside the hull, held to the hull with 8 stainless bolts+goop along with a stainless wire going between the swinging part, up a standpipe, and into a winch. I have watched a few more YouTube videos and think I have the basic concept for jacking the boat to remove trailer to access this area. The iron is looking rough but not pitted so far. So I may take a few beats to sand and repaint. Last quote on sandblasting this was 500$ so I don't see that happening...
Big dreams, small boats...

Riley Smith

I hope you have a good jack! Or even better, a chain fall and a big beam. I bought a 3 ton floor jack awhile back and wonder why I haven't had one all of my life. Like, young men should be issued their very own 3T floor jack! Jack the F-150 up in two seconds! I have all the tools to make angled cuts in timber, and can weld up something if I can get the metal. All of these skills can be very useful in such a job. Be careful of el cheapo pipe jacks( although I'm used to picking up lots more than a ton). All of the wooden stuff (blocks, timbers, wedges, etc.) you use to temporarily hold something in place is called cribbing, and you'll need some for sure. Squares of plywood to spread the load. 4X4s and 2X4s. I jacked the catboat off the trailer awhile back and it was a dodgy deal if I ever saw one. Not only is the boat extremely wide, it has rocker for and aft, and it makes it really difficult to keep steady. Of all the stuff I've ever jacked up, it is the most difficult to get right. Most boats would be lots easier though. A good partner and extra set of hands and eyes is invaluable. If you don't jack your truck up for fun, then proceed with caution. A grinder and a stock of heavy duty sanding pads is lots cheaper than a sand blasting crew!


Thanks Riley. I do have a good floor jack and some experience with heavier machinery; I do not have any overhead gear. One of the videos the guy made his own 4 stands from wood, the second other guy spent the money on 2 real Brownell boatyard stands and a strap to a ceiling joist, the third used concrete blocks and 2x4's and had to reposition the bow blocks to let the trailer pass since the original third support interfered with a trailer cross member. The two doing keels did not have the stub just the swinging iron. I will need to be about 3 feet up for the trailer to clear the keel.
Big dreams, small boats...

Charles Brennan

Spot, So I went and reviewed my pics/articles from the Great Swing Keel Refurb of 2014/2015.
A few comments from the articles:

1) Was very disappointed with sand blasting.
a) If you have any significant scale build-up, it takes exponentially more sand blasting to remove it.
b) Needle gun would have been great, but could not obtain/rent one.
c) Started with an ordinary ball peen hammer, but quickly switched to a welding/slag hammer.  This did an excellent job knocking off scales of rust.
d) After that, a 4.5" angle grinder made short work of the rest of it, and also helped at rudimentary fairing.

2) Phosphoric acid was next. 
a) It keeps rust from re-forming by converting whatever oxidation is on the keel surface into Iron Phosphate.
b) You can test for any missed rust spots by applying water, waiting for a day and observing the rust. 
c) Grind off the rust spots and apply more phosphoric acid. (I used an ordinary chip brush.)
d) You will get a grayish/whitish color when there are no more rust areas.

3) Coal Tar Epoxy. (CTE)
a) This is great stuff.  When I originally made keel repairs in 1999 (the reason I first found my way to TSBB and got help from Charlies Jones and Noemi Ybarra) I mistakenly applied ordinary epoxy fairing and then CTE.
Bad Move.
b) The fairing epoxy allowed moisture incursion and over 15 years, allowed rust scale to build up.  THIS Time, I applied CTE, (3 coats) THEN fairing epoxy.
c) You can get a gallon can from Grainger along with (IIRC) either a pint or a quart, of the hardener.
d) You WILL need a heavy duty stirring mechanism (i.e., forget using a battery drill and a paddle.)
e) The idea is to get from crunchy peanut butter to Hershey's syrup consistency.
f) Tried rollers and paint brushes, with roughly equal results.

4) Epoxy Fairing and NACA 15
a) Originally intended to build up sides and then fair to a NACA 15 foil.  Discovered to my consternation, that there already WAS a NACA 15 foil hiding under all the rust scale!
b) Google around until you find templates that you can print out and glue to cardboard to check against your keel.
c) Epoxy faired anyway, just to smooth out finish.

5) Paint.  Used some Interlux paint in a color similar to the original keel color.

9 years and the keel, (with the exception of a few spots on the leading edge from coral rock groundings) looks virtually new.

Hope this helps,
Charles Brennan

Travis Chapman

I did a partial lift a few years back to replace a swing keel cable; had to drop the board enough to grind off the shackle. I also used a 3 ton jack and cribbing to spread the lifting load, then more 4x4 cribbing to hold it up. Lot of test jiggling to ensure stability, and I was still partially on the trailer. I'm working through a 4-frame cradle of 4x4 amd a lot of excess 2x6 I've got to do the CTE keel repair Charles mentioned (my Windrose is due!) I'm confident I can manage a wooden frame, with appropriate weight distribution, with that material, at a reasonable cost. Mostly because I don't want to manage the welding, though I could do that too.
SV Panda Paws
Windrose 18
Glyndon, MD


Big dreams, small boats...

Riley Smith

We have a travel lift at work and I lick my chops every time they fire that thing up. Of course way too big for my use but it makes weight and moving things no big deal.


Here is the keel in question (woohoo pics are uploading again :) thanks Kurt)
You cannot view this attachment.
Big dreams, small boats...


When I had to lift my 2400 lb Starwind I had a 1500# chain hoist available. To make that work I built a substantial rear bunk out of 2x4s and 2x6s. It was tall enough to fit snugly under the stern when the trailer wheel was cranked all the way down in the front. Then I lifted the bow with a sling and the hoist, getting the whole boat high enough to pull the trailer out. Since I was sharing the load between the bunk and the hoist I was holding about 1200# up with each. You could do the same thing with a 1000 lb jack under the bow and some cross beams and blocks strong enough to support 1000 lbs. Once you jack the bow up high enough. You would have to put the beams under the bow, supported at either end with blocks set far enough apart for the trailer to fit between. I'm not sure what size beams you would need to support 1000lbs with an 8 plus foot span, but I'm sure that you can look it up. I would guess that 2 or 3 2x8s would do the trick.

Your cost would be less than $100. I can send you a picture of the stern bunk if you are interested.


RF, that procedure sounds solid, thanks.
I ordered 3 of these last week, rated 2500# each:

Planning on 2 at the stern and 1 to play leapfrog with a jack between the cross members as the trailer is extracted. I also considered making the old 4" square steel basketball pole on the edge of the driveway into a derrick for lifting the front but that seems like a lot of work... :)

As to figuring out the beam, I recall sitting through an hour of calculations in a college level structures class only to have the instruction say at the bell 'this is the last time you'll do this, from now on look it up in the back of the book'. The other takeaway is that a 2x4 is 4x stiffer on edge than flat.

Big dreams, small boats...

Noemi - Ensenada 20

FYI, I used an engine hoist to help get my boat off the trailer.

I need to do some repair to my web pages....the description is here, but the photos don't show up right now.



Big dreams, small boats...