The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
How much/many rust spots are OK on a C-25 swing keel? I just pulled mine out of water after 3-4 months in (fresh) water, and can see a few rust spots in the visible part of the SK. Assumption would be about the same amount of rust on the hidden 2/3, just how concerned should I be with a "few" rust spots? Not sure how keen I am on wrestling with a 1200 lb. monster, a local rigger has a boat lift that may be better suited for the task.
The rest of the bottom isn't quite ready for sanding/repainting, so if I can put the job off a year that would seem the best approach (bottom and keel at same time).
I do have a shop with beefy I-beam construction that swallows and could probably (checking this out with a mechanical engineer neighbor) lift the boat minus its 1200-lb keel. Is that a valid approach, that is, lifting the boat off (3' lift I would guess) keel and trailer, and setting her gently back down on sleepers or bunks on turnscrews after backing the trailer/keel out?
I think that's a pretty common issue on the earlier boats with a steel keel. If it's still out hit the spots with a wire brush on a drill, prime and paint the spots within a couple of hours of running the brush over the spots. Or do nothing, don't think it will make that much difference as long as you take care of next Spring.
I like the idea of lifting the boat off. Seems like it would make sense. I'm dreading eventually dropping my keel as well as addressing small blisters on the hull.
Honestly though, little bit of rust shouldn't be grounds for dropping it. Unless you are planning to take the keel down to fair it and seal it as well as replace all the pivot and lifting hardware it can be taken care of in-place when you haul. I've been addressing problem spots as they appear every two years when I pull out for a bottom job.
The rusticles usually are a good indicator where the barrier is broken and exposed to the water. I use a wire-brush and sand paper to remove the rust and feather out the paint while cleaning with acetone, then 2 coats of interprotect 2000e before they put the new bottom on.
I addressed some spots this April and when I hauled out last week or the week before they still looked un-touched.
If you can tell, I may touch the bottom occasionally Actually, it was the wife this year who did it a week after the new bottom!
Captain Rob & Admiral Alyson "David Buoy"-1985 C25 SK/SR #5053
Rust is a pretty normal thing on the swing keels and older fins. There's even more cast iron there than you think--1500 lbs. in the swinger. Various folks here have ground them down and coated them with epoxy--I don't know how permanent that turned out to be... I'd only be concerned, particularly in fresh water, if I was in a marina with possible stray current--in that case the loss of metal could be greater, making sacrificial anode a good idea. It would protect not just the cast iron but the associated metal hardware.
Dave Bristle Association "Port Captain" for Mystic, CT PO of 1985 C-25 SR/FK #5032 Passage, ex-OUPV Now on Eastern 27 Sarge (but still sailing when I can). Passage, Mystic, and Sarge--click to enlarge.
I fought rust and big paint blisters on the keel of my fin keel boat for 20 years until I put a sacrificial anode on it. That stopped it. It appears that the reaction produces a gas that collects under the paint and lifts the paint into big bubbles. You also see some reddish rust spots on the keel where the paint is thin, but that is just a matter of covering them with paint and/or a barrier of some kind.
Steve Milby C&C 35 Landfall ("Captiva Wind"); Cal 25 ("Fahrvergnügen") Past Commodore
Dave, are you saying the boat weighs only 2 tons minus its keel, boom, mast, outboard, etc.? That would be doable (liftable) in my shop if so. Wonder if I can weigh boat and trailer at a truck weigh station?
Rob, is that a homemade superstructure holding your hull up? If so, what are the specs for lumber and fasteners? How much weight are you calculating? I've heard a lot of numbers but I'd like to get an estimate within a ton so ... :)
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.