keel bolt maintanence

[bestfriend]

I have a little rust on my keel bolts as the result of a leak that kept the bilge wet, but thats another story. The nuts and plates were originally painted and retained moisture under the paint, which has now flaked off revealing the rust. So, should I just grind off the paint and rust and coat with something water resistant, or repaint?

[Idiens]

My keel stud backing plates were seriously corroded after some thirty years buried under silicon rubber and paint. I am not sure if they were even stainless steel. So I replaced them all with 316 and leave them exposed and unpainted. If yours are stainless steel, I would leave them cleaned but unpainted.

[sailingdog]

If they are stainless, the paint isn't helping them any. Stainless steel needs oxygen to work properly. If they were painted, and the prep job wasn't perfect, that likely contributed to them rusting after a while. What's worse is that it may have hidden the corrosion from casual inspection. Leaving the bolts uncoated is probably best.

[Gary M]

If you are sailing a CS they will be SS washers and nuts. Saltwater will produce some rusting but hopefully not much. If it appears to be mainly cosmetic then you could just clean them up and leave them alone. If it looks worse then replacemnt would be in order.
You should think about retorquing the nuts if that has not been done recently.

Gary

[olson34]

CS built a well-desgned high quality boat, but at about 20 years (to reduce the years to a round number) time has come to drop and rebed the keel. The part of the threads you can see in the bilge is not where the problems will be. The oxygen-starved area under that and above the lead is where the threaded rod ("keel bolt") could be corroding away. We have a well-documented thread or two on this subject, with photos, over at ericsonyachts.org. While lots of boats could go an additional decade, this is a preventative maint. item that should not be forgotten just because it is mostly out of sight.
Next time you have the boat out on stands, perhaps talk to the yard or your surveyor about removing one or more nuts and washers and inspecting threads before torquing them up again... ??

Regards,
LB

[sailingfool]

The bolts on our CS 36T are not painted, nor are Halekai36's, pic below. I never noticed before, but the backing plates look like aluminum to me...I would leave unpainted. A little rust is natural.

In my seven years participation on the CS discussion list, I don't remember anyone ever dropping a keel for maintenance, but it may be worth a question to see if anyone has actually done it - it certainly is nowhere on my radar.

[bestfriend]

SS they are, and I will strip them and leave them. Thanks for the heads up olson. She comes up next year and I will look at that along with repairing a through hull and possibly an awlgrip job. I love that light blue that halelai36 has on his CS36.
The plates in that photo do look like alum. I can't see mine, covered in paint.

Addendum: Backing plates are another issue. I don't know about the 36, and I have not checked the CS board yet, but the 34 is lacking plates on the deck hardware. I am wondering how the through hulls are set up. There doesn't seem to be much support on the inside.

[Gary M]

Those plates look like SS to me, aluminium would be corroded much worse than that. Even SS gets a dull protective layer which you can see here.
It is easy to determine, aluminum is much softer and will scratch easily with a screwdriver etc.

Gary

[bestfriend]

Originally Posted by Gary M

Those plates look like SS to me, aluminium would be corroded much worse than that. Even SS gets a dull protective layer which you can see here.
It is easy to determine, aluminum is much softer and will scratch easily with a screwdriver etc.

Gary

I'll get out the rusty, er trusty, magnet

[sailingdog]

BF-

Be aware that the better austentic grades of stainless, like 304 and 316, are non-magnetic. The martenistic grades of stainless are magnetic, and generally not recommended for marine use.