How Strong Is The Modern Keel???

[sigbear]

I am considering buying a Catalina 310 or posibly Beneteau 311.

I have never owned a sailboat, but have chartered many 30-33' boats in the last 20 years.

My question is how strong is the modern keel (1995-2009) compared to boats made in the 70's and 80's. The reason I ask is, 25 years ago a friend bought a 1978 columbia 28' or 30' and I remember sailing with him on lake champlaine and we were motoring at between 5-6 knots and hit a rock about as big as a volkswagon and stopped on a dime.

He sailed the boat the rest of the season and when he hauled out the boat the only obvious damage was a dent in the keel. I remember looking at the keel, keel bolts and the hull for damage and all I remember is the dent in the keel.

My buddy sailed this boat for many years after (not sure if he ever hit hard like that again) and I was always amased at how the boat took the hit.

How would a modern day Hunter, Catalina, Beneteau handle such a incident?

Sigbear

 

[Warren Milberg]

I had an old 1960-something Columbia 28 many years ago (1st cruising boat) and it, and its keel, was built like a tank. While I would guess that more modern recreational sailboats are built a lot lighter, many modern materials and technologies are superior to some of the older ones used. While it is not possible to answer your question about how a 1995-2009 boat/keel would stand up to a hard grounding, I continue to believe that "keels just don't fall off."

The few instances that I am aware of that involved the keel departing the boat always seemed keels that left a lot of prior signals and signposts:
rusty keel bolts, water intrusion at the keel/stub joint, rust oozing from the joint, and so forth. While some believe encapsulated keels are superior to keels bolted to stub, they, too, can have their problems and are much harder to diagnose.

If my keel took a hard hit, I'd immediately have the boat hauled and professionally inspected.

 

[Ross]

It is my opinion that no one would build a shelf to carry a ton on its outer end and attach it to a wall in the manner that modern keels are attached to boats.

 

[tsmwebb]

It is my opinion that no one would build a shelf to carry a ton on its outer end and attach it to a wall in the manner that modern keels are attached to boats.

Any yet, the VAST MAJORITY of them have no problems even when abused and neglected. Evidence suggests they are, as a class, strong enough.

--Tom.

 

[BobM]

I don't think you can take them as a class. If you are concerned about using your keel as a depth sounder I'd suggest you take a common sense approach to keel design. If you are sailing in a shallow area it may be worth the performance sacrifice to go with a shoal design. Shoal keels are often attached over a longer length of the bottom too.

 

[tsmwebb]

...If you are concerned about using your keel as a depth sounder I'd suggest you take a common sense approach to keel design....

I like the way you used "common sense" and "using your keel as a depth sounder" in the same sentence.

--Tom.

 

[Witzend]

We took a pretty good hit into hard bottom on my C310, no problems evident when hauled a month later.

 

[Ross]

One of the things to note here is that grounding often results in a haulout to inspect for damage. With my full keel, soft bilge boat I don't have any concern about hitting bottom.

 

[tommays]

IHHP They are just understanding how long term stress causes micro fractures in fiberglass boats that are NOT easy to see untill it becomes so weak it fails compleatly in a short amount of time

 

[Ross]

IHHP? New to me acronim please translate.

 

[tommays]

IMHP typo


The first 1994 J80 that had sudden keel failure last year was recovered and taken back to Jboats and it was found to be wornout


The bad part is they are not able to offer a solution to do a repiar of the boats that have not failed

 

[tommays]

Untill the recent Oday keel problems i though it was a shinny race boat keel problem BUT it would seem anything that allowed any flexing in the orginal layup is going to have a problem

 

[Jonsailr]

I knew a woman who hit a ledge in Woods Hole, MA at approx 8+ knots in a Catalina 30. The impact wrenched the entire H frame assembly such that the whole boat was torqued, cabinet doors would no longer close, etc. But the important part was that the keel stayed put in about as hard a grounding as is practically possible given boatspeed and current. Unless you plan to regularly sail in an environment with the challenges of ledge and current provided by Wood Hole, I would not lose any sleep whatever about the keel attachment.

If you still want to obsess, you can always have the keel bolts renewed as soon as you take possession

Happy sailing.

 

[bffatcat]

old keels vs new

My vintage 1975 Pearson26W has a cast iron keel. dosent leak a drop no seep nothing
Keel bolts look exactly the same as when I bought the boat 10 years ago. Im sure the new
keels are adequite but I do not think they are as durable as 60`s and 70`s boats. They just dont build em like they used to. Cast Iron keels have gone the same way as atomic 4`s.
and obviously they will stand up to a grounding better than lead. The only shortcoming I can
see is an occasional rust spot that has to be attended to

 

[zeehag]

my 2 boats have enclosed or encapsulated keels---encapsulated in fiberglass as part of the hull made this way on original layup---with many layers of glass used --made in 1979 and 1976....there are no0n enclosed keels wherein the fiberglass is but molded over the steel keel or iron keel, these use bolts and the molding of the g lass to keep out water.....these wear out. in modern boats i do not know how the keels are made--are they enclosed or open to the water ??
molded into the hull after lay-up?? the enclosed ones can be subject to eggshelling if they hit something---tiny cracks as in cracking an egg.....the open ones can be subject to wear and keel bolt failure......

 

[tsmwebb]

... Cast Iron keels have gone the same way as atomic 4`s.
and obviously they will stand up to a grounding better than lead....

Iron keels are generally considered inferior to lead when grounding because they absorb less energy. It is less bad to put a dent in your keel than to split the hull.

--Tom.

 

[BobM]

Thanks!

I like the way you used "common sense" and "using your keel as a depth sounder" in the same sentence.

--Tom.

I am a firm beleiver that there are three types of sailors...those who have run aground, those who will run aground and liars.

 

[sandpiper10471]

The issue is not the strength of the keel but the integrity of the supporting structure. In the mid 80's to 90's many boats were built with a grid structure attached (somewhat) to the hull to carry the loads of the keel. If the grid was bonded and tabbed to the hull, great strength was achieved. However, if the grid structure had interconnecting "pans" which were gooped up and laid onto the hull, then bonding was often compromised. When the keel hits, the hull bottom flexes and the grid structure may delaminate from the hull. Then the pans must be cut out, the gelcoat ground off and the grids properly tabbed to the hull. A dirty nasty expensive job - but the good thing is it can be done in the water provided the bilge is dry.

I have rebuilt a half dozen or more boats like this which hit rocks (not necessarily that hard). In each case the glass surfaces which provided the bond came out glossy, indicating poor mechanical adhesion. Once tabbed properly, no more problems. These boats had sufficient integrity for normal operation but not for impact. It is my belief that most builders have changed their bonding methods over the last decade or so, making them stronger. But then I haven't seen many of the models on the market.

The other issue not yet addressed is crevice corrosion of the stainless keel bolts but others on this site are, I am sure, more knowlegable than I on this subject.

 

[Ross]

There is nothing made by man that can't be distroyed by man. In our marina they take boats apart with a backhoe. Forty foot fiberglass cabin cruisers smash up just as nicely as twenty foot daysailors. Having said that there are some forty year old boats that don't have a visible caulk line at the hull/keel joint and there are some fifteen year old boats that need new caulk each year. Something gives way and there is movement.

 

[hfmckevitt]

S2.9a

I don't think you can take them as a class. If you are concerned about using your keel as a depth sounder I'd suggest you take a common sense approach to keel design. If you are sailing in a shallow area it may be worth the performance sacrifice to go with a shoal design. Shoal keels are often attached over a longer length of the bottom too.

Your S2 looks good and I agree with you thoughts, I believe he might be thinking of the keel in the scents of the keel as a counter weight. I also own a 1981 S2.9c great boats, still working hard to bring it back to it's original. From your pictures it looks as if the non-skid surface is painted if so can you tell how you either maintain it or re-surfaces it.

If you want you can e-mail it directly to me.

Thank you
Henry
hfmckevitt@comcast.net