|Topic Review (Newest First)|
|02-11-2011 06:00 PM|
I know this is probably another one of those ‘no one universally right answers’ questions. In other words an argument can be made for either type of keel. (For the record, I personally strongly prefer a bolt on keel an d would rule out buying any boat with an encapsulated keel.) Here’s the way I see it.
Bolt-on keels tend to offer more performance since the ballast must be cast and without the keel stub skin thickness tend to be lower relative to the center of bouyancy. They also have significantly less wetted surface and frontal area making them theoretically faster on all points of sail. They are simple to repair and generally can be repaired satisfactorily no matter how bad the mistake.
On the down side they are more expensive to build; requiring precision casting, bolt hole drilling and a lot more hand fairing. They are higher maintenance requiring fairing every 10 years or so and new keel bolts at some point in the boat’s life.
Encapsulated keels are less expensive to build. There’s less labor and less precision required. Boat builders will often use less expensive forms of ballasting with encapsulated keels, such as iron or lead scrap cast in concrete, resin or other binder further reducing costs. If they are not damaged in a grounding, encapsulated keels are less expensive to maintain.
On the down side they are less efficient. Their real downside is the difficulty in doing a proper repair. Typically, in a hard grounding a number of things happen on an encapsulated keel. Typically the skin of the keel encapsulation gets ruptured and separates from the ballast. This allows water into the small cavities between the keel and the ballast and once wet it can mean the ‘beginning of the end’ for the boat as this permanently wet fiberglass blisters itself from the interior and the wet areas spread around the ballast. This is especially a problem on a boat that is hauled out for cold winters where freeze/ thaw cycles can really pry the skin loose from the ballast. The problem gets worse when the ballast contains ferrous materials. Here the ballast begins to rust and can reduce the ballast into a loose mass of matrix and rusting iron.
Beyond that, in a grounding the ballast is often forced upward as well. In an encapsulated keel the membrane of the hull is at the outside of the keel and the membrane above the ballast is often quite thin. In a bad grounding the ballast keel is often is pushed through this membrane causing a serious and difficult to repair damage and leak.
We grounded a boat with an encapsulated keel that we never could permanently fix for as long as we owned the boat. The problem would get worse with every year, spreading from a small dimple on the leading edge of the keel to an area that was much of the bottom and sides of the keel.
Lastly, it is very hard to lay-up the glass in the keel cavity. As a result the glass work in this vulnerable area of the boat is often inferior to the glass work else where on the boat.
|02-11-2011 05:53 PM|
|PeterSailer||yeah, encapsuled lead keel are IMHO the best way to go, thats how our cal34 is|
|02-11-2011 05:24 PM|
|sailingdog||I love not having to worry about keel bolts.|
|02-11-2011 04:49 PM|
|PeterSailer||A wet bilge is obviously bad but pretty hard to avoid on the sailboats, especially when you have a inboard engine with the cutlass bearing dripping slowly... And then you have the leaks in the deck, around the chain plate, on the hull/deck joint...|
|02-11-2011 02:41 PM|
Originally Posted by tommays View Post
|02-11-2011 02:37 PM|
I dont what year you C30 is and if your before or after the plywood keel sump change over in 1987
I can tell you i passed on diesel C30 becasue of this issue before i went for the Cal 29 due to bad keel bolts not really being a DIY fix item
|02-11-2011 02:09 PM|
I suspect that you might find something similar to what I discovered shortly before I purchased my boat in October '10
|02-11-2011 01:59 PM|
Keel Bolt/Bilge Issues
Just wanted to share some info and pics with everyone..
I've been sanding my bottom in order to do any necessary repairs, new barrier coat, and antifouling, etc. While sanding I noticed a crack a few inches below the keel joint...and I saw what looked like rust stains coming out of it. The only place on the entire boat that has any rust is in the bilge. My keel bolts are horribly corroded (an issue I plan to tackle in a few weeks). I also noticed that the only blisters on the entire boat were above this area...not a single blister anywhere else.
Naturally I got very concerned when I saw the rust and began to open up the crack (first picture). I want to do a proper repair so I decided to expose everything in that area where water could be seeping down from the bilge (second picture). And in the third picture you can actually see some water coming out right at the keel joint.
Below are the pics...
This also raises a lot of new questions for my fellow SN'ers..
1. Do you think that the water from the bilge caused the blisters to form?
2. It's hard to keep the bilge dry all the time...would it make sense to barrier coat the bilge?
3. My keel is not encapsulated. Does anyone advise that I do that at this time? Would I benefit from it?