O'Day 302 Loses Keel - Check Yours!!

[BobM]

A broker, who used to sell O'days, tried to get me to look at a 302. I found something about this keel issue on line and said "no way." He said that it was an issue with early boats and that O'Day was informed and fixed the issue with later boats and repaired early boats. Looks like they missed one. Glad I took the pass. Also glad my keel is integral to the hull and very strong...although that approach has its own issues.

If I had a 302 with a wobbly keel I'd drop it and rebuild the stub entirely, if necessary (wet plywood and/or thin fiberglass). Those wings are just massive and must place an enormous stress on the joint.

I also walked from a last generation Newport 30, which showed extensive keel damage after a grounding. There just wasn't much "meat" at the turn from the hull to the keel stub and it was cracking at that juncture, NOT the keel to stub juncture.

 

[sailingdog]

CW is a reference to the Cynthia Woods, which was a sailboat that lost its keel and resulted in one death...that of the safety officer, who managed to get all the rest of the crew out of the boat at the cost of his own life. It could have easily killed all five who were aboard. The Cynthia Woods was owned by Texas A & M.

Roger, thanks. What does "it's the CW all over again" mean -- I'm a bit lost there.

I sense the advice is to haul the boat, drop the keel and see how much thickness I have on the keel stub? Is that right?

If my stub is 1/4" thick -- clearly that would need to be built up. But what would likely be a correct thickness: 3/4"....1 inch? 2 inches?

Assuming the keel bolts are long enough to accommodate the additional thickness, is it then a relatively simple matter of re-installing the keel over the new, thicker stub, tightening down the nuts and sailing with a lot more confidence that disaster might not be around the corner?

Thanks.

 

[Roger Long]

Assuming the keel bolts are long enough to accommodate the additional thickness, is it then a relatively simple matter of re-installing the keel over the new, thicker stub, tightening down the nuts and sailing with a lot more confidence that disaster might not be around the corner?

Fixing the keel stub and hull should be relatively easy and inexpensive. The bolts will probably be the hard part. I would be surprised if they are long enough to build up sufficient keel stub thickness unless the keels were designed for a thicker laminate and this is just the result of quality control on the layup line.

You really can't add too much glass to this area. It should be run as far up out of the sump and along the bottom as you can reach making successive layers shorter to taper new laminate. I would use epoxy. The glass can be laid in transverse strips which will make handling it easier. It's only transverse strains which are critical and slight overlap of the strips will be sufficient. This part would be a reasonable weekend job although incredibly unpleasant.

This is a good place for overkill as long as the thickness of the new stuff can be tapered out. I'd like to see a good 1/2 to 3/4 of an inch on top of the old stuff if it were my boat.
I would also have a piece of 3/8 to 1/2 inch aluminum cut to fit the inside of the sump, set it on wet resin and mat, and then run a layer of glass over it to seal it.

Lead is fairly easy to drill and tap. The existing bolts are probably cast in place so you would have to cut them off. Have new ones made of bronze boat shafting with several inches of thread on one end and just enough for two nuts, washer, and backing plate on the other. The tops can be squared for driving. Make the bolt holes in the keel stub about 1/4" oversize. Set the boat on the keel with wet resin and mat between. Fill the space around the bolts with 4200 or similar bedding compound and take up the nuts inside.

Expensive job if you can't do a lot of it yourself. This probably is overkill but the incremental cost and effort of making it a solid backbone for the boat isn't that great compared to doing in minimially.

 

[Maine Sail]

Drill & tap lead..

Lead is fairly easy to drill and tap.

Roger,

Drilling and taping lead for keel bolts is not necessarily the best repair practice. Keel makers generally use J shaped bolts that are set into the lead during the pour and it's to prevent the threads from pulling out of the rather soft lead over time.

Mars Metals up in Canada can actually replace J bolts in a keel with a very interesting process to address these issues. You simply drop your keel, put it on a pallet and have it delivered to them via common carrier.

Another way to replace them is to drill a 2 inch hole sideways into the keel about 6" down then used some 2" round bronze stock tapped to accept the new keel bolt. Your are essentially creating a 2" diameter barrel nut. I used this procedure on my Catalina 30 and would not do it again because it was very hard to completely seal the barrel nut. The Mars process is a far better and stronger way to replace keel bolts that have suffered crevice corrosion.


Mars Metals Keel Bolt Replacement (LINK)

 

[Warren Milberg]

When one thinks of all the many types, sizes, and configurations of recreational sailboats built, and by whom, over a lot of years, it seems to me that the instances of keels actually falling off, without a prior trauma, must be infinitesimal. My guess would be that the probablity of your keel falling off is less than that of an engine falling off a wing pylon of an airplane. Instances of keels "just falling off" catch our eye and command our attention because they are, in fact, extremely rare.

 

[Roger Long]

Drilling and taping lead for keel bolts is not necessarily the best repair practice.

No, but it is adequate if combined with sufficient thread length and/or oversize bolts. You certainly need a lot more than the typical 1-2 bolt diameters you would use in steel. It won't work well with pure lead but most keels are poured from scrap lead which will have picked up enough other metals to be a bit stiffer and harder.

Any project like this should have some engineering done aside from forum banter. I should have pointed out to the fellow that my response was just a scope of work idea and general concept and not a repair specification.

 

[RichH]

This is a good place for overkill as long as the thickness of the new stuff can be tapered out. .

Roger --
Tapering .... is especially important to avoid 'stress concentrations' and is probably the prime design characteristic/reason that encapsulated keels dont fall off.

The FIRST item of inspection when removing a bolt-on-keel is the examination of condition of the **bolt holes** in the Fiberglass stub. If any of the holes have become 'elongated' or 'egg shaped', then significant increase of the thickness of the laminate should be considered. Elongation of such holes is typically a flexure/compression failure caused by 'stress magnification' AT the hole caused by the bolting when the boat is heeled (called 'projected bearing load' and is commonly at 1/3 of tensile vale of the material, not including any 'safety factor') - the value 'should' be developed though dynamic testing of the material. Also, If the keel bolts do not remain correctly TORQUED the Fiberglass laminate will receive undue/inordinate stress from the bolting and 'washers', the force of the 'torquing' acting to 'prestress' (make stronger) the mating face of the FRG 'stub'.

As one who engineered mega/critical stress, I always wince when I see a bolt on keel on a FRG boat. My conservative design/engineering preference would be to use an integral BACKING PLATE instead of 'just washers' on those keel bolts ... as such is normally found in just about any other critical stress joint in a FRG boat!!! The drawing together of the keel and the backing plate when the bolts are properly torqued would then 'prestress' the vulnerable 'stub' & would protect the bolt holes in the FRG from 'projected bearing stress tearout'. To me its 'amazing' that bolt-on-keels are not attached with a sufficient backing plate .... and then specific direction for regular maintenance 'torquing schedules' of the bolts!!!

A catastrophic failure of a bolt on keel is totally inexcusable ... its the DESIGN that failed because it had no inbuilt REDUNDANCY (sufficient Factor of Safety including 'fatigue' considerations).

 

[RichH]

When one thinks of all the many types, sizes, and configurations of recreational sailboats built, and by whom, over a lot of years, it seems to me that the instances of keels actually falling off, without a prior trauma, must be infinitesimal. My guess would be that the probablity of your keel falling off is less than that of an engine falling off a wing pylon of an airplane. Instances of keels "just falling off" catch our eye and command our attention because they are, in fact, extremely rare.

Imagine what happens (in the USDOT/NTSB or Fed Aviation agencies) when an infinitesimal occurrence happens in aircraft, railroad, or other public conveyance. I would guesstimate and offer that more keels fall off of sailboats than airplane wings, front axles of busses, etc., If this was a boat under 'commercial service' there would be at least 5 govt. agencies immediately investigating (plus the inevitable horde of lawyers).

 

[tsmwebb]

...
You really can't add too much glass to this area. It should be run as far up out of the sump and along the bottom as you can reach making successive layers shorter to taper new laminate. I would use epoxy. The glass can be laid in transverse strips which will make handling it easier. It's only transverse strains which are critical and slight overlap of the strips will be sufficient....

First, you need to make sure the existing laminate is sound. If it has cracks, delams (crushed resin, broken fibers or voids) or blisters then you don't want to just lay new glass on old. At that point you need to remove the offending bits. Bad resin is as likely a culprit here as bad design or layup. There are a host of problems that you could run into if you have a bad laminate under your fix -- including real difficulty making the whole thing stiff enough to stop the wobbling... If you are going to beef the thing up, I would run laminates up the outside of the sump as well as the inside. That makes the job a good deal harder -- you'll have paint removal, laminating (upside down), fairing and painting. But, you'll end up with a stronger stiffer sump than you can get glassing just inside... You'll need to cove the corners inside and run your structural glass around a decent radius outside but you'll also want solid glass out to the edges of the sump -- there are several ways of going about that. I agree that this is a good place for epoxy -- epoxy is stronger, has better bonding and is less likely to absorb water. I'd do a medium/low pressure vacuum bag on the lams inside and out. It is easy, doesn't take any special tools and will not squeeze too much glue out, but it will help clamp the whole thing down which will give a better result. Again, I'd shop around for some advise from a design/engineering firm rather than just having the local surveyor or glass guy put it together.

--Tom.

 

[Larry14133]

I currently own a 302 and am of the opinion that this is a Maintenance issue. I torque the keel bolts to 250 Foot Pounds every fall, Dry the bilge and ad some antifreeze when I winterize. The keel wobbling is what causes the lamination failure. This is not and instanious failure it’s a slow process with symptoms such keel wobble being ignored.

Regards,

Larry

 

[Hermit Scott]

To me the idea of having nuts and washers holding a catilevered 4000 lb. lead beam whose center of gravity can be 18" away is a bad idea. But that is how most fin keels are made. I know the ideal way to have a fin keel is so it can be easily removed with out too much fiberglass work, but some of us have some old boats. The only logical thing to do is reinforce the keel from the outside as well as the inside. The fiberglass on the outside will be in tension or compression when the boat heels which is much better than relying on bolt heads that are being pryed at a bad angle.
When the work is done while the boat is sitting on it's keel the outside reinforcement will take alot of the stress that was on the keel bolt when the boat is put in the water.
This reenforcement is not that bad of a job. A gallon of epoxy and $40 of glass will give you some piece of mind.
There could be concern for performance, because of changing the shape of the keel, but that was a lower priority for me. I'd rather know the keel is not going to fall off.
I have a friend here with an O'Day 322 and I let him know of this. We drilled small holes into his keel sump to see how thick it was. We found that it was less than 1/4" of glass before we hit lead. He's not very happy about this. What can he do?

 

[Maine Sail]

Just found my notes

I found my notes the other day from my conversations with Catalina during the keel re-set of my old C-30. I had spoken with Gerry Douglas..

Here's what I had.

The early Catalina 30's (70's era) had a keel stub thickness, below the wood core, of roughly 1/2" solid fiberglass (though some got more and some less, mine had less) and then 3/4 inch plywood which was covered by about 1/8" of fiberglass on the bilge side.

The later C-30's up to late 1987, when they stopped using a wood core in the keel stub, had a keel stub of about 5/8" of solid fiberglass then 3/4", and in some boats 1.5", of marine plywood which was covered on the bilge side by about 1/8" of fiberglass.

The current C-30's have a keel stub thickness of 7/8" or nearly 1" with no wood to rot!

This is a far cry from the photo's above of the O'Day 302 in which the keel stub appears to be about 1/4" thick in total. Two 1988 30 footers, one with a keel stub 7/8" or nearly 1" thick (Catalina), and one with a keel stub that is significantly thinner (O'Day), maybe 1/4"? As far as I know I don't ever recall hearing of a C-30 that lot it's keel due to a keel stub failure and I know many of them up this way have hit solid granite ledges.

Maybe the layup of the keel stub and its thickness does matter..?

 

[Ross]

I currently own a 302 and am of the opinion that this is a Maintenance issue. I torque the keel bolts to 250 psi every fall, Dry the bilge and ad some antifreeze when I winterize. The keel wobbling is what causes the lamination failure. This is not and instanious failure it’s a slow process with symptoms such keel wobble being ignored.

Regards,

Larry

I always torque bolts to "foot pounds" I don't know how one would tighten bolts to "PSI". But I would like to learn.

 

[Larry14133]

Ross,

You are correct i did mean foot pounds not inch pounds in this application.,

 

[Ross]

I wonder how many old boats are simply abandoned because of keel problems before they become news worthy events. I have seen fin keel boats that were in apparently perfectly good condition (that is no visible signs of a keel/hull joint) that had only about 6 inches of width at the connection point. In order to support such a load when the boat was heeled would require a substantially long, wide and thick fiberglass bottom.
You can't cantilever a shelf on a sheetrock wall and trying to hang a fin keel on a thin fiberglass hull would be just as foolish. Some, no most, boats are built with well reinforced keel support structures we are beginning to see the results of the marginal structures.
This is easily seen in all types of construction. All new boats look good, as do new houses and cars and trucks but after a few dozen years pass gravity and wear and tear start to show where the weak places are. Some boats are just as structrually sound today as when they were launched forty years ago. The Alberg 30 comes to mind. I sometimes wonder if some builders plan a finite life expectancy for their boats.

 

[tommays]

My 1981 fin keel J24 was most likely overbuilt a bit as it was the first Jboat and after 28 years of regular racing it shows no signs of of problems

The sump is fully visable when you pick up the cover and the glass seems to be very heavy mat

The newer bigger Jboats were the loads went UP are having a issues that can be repiared EXCEPT the J80 at this point


I also race on a 1970 C&C 35 (solid glass hull) with a 7' fin keel that is still rock solid and the orginal owner raced the boat full time and the current owner has used it in 270 races at last count


Both boats are in the owners driveway every winter for any issues to be seen

SO i have to conclude if the orginal build did NOT allow flex to casue micro-fractures Fin keels LAST a long time

 

[Chris Burti]

I am following Claude's lead here, while the layup is certainly not robust, it appears to be substantially thicker than the stated 1/4". I can see what appears to be at least three layers of mat sandwiching two layers of heavy woven roving. I suspect that the pictures are a bit deceiving because we are not seeing a clear shot of a complete cross section of the layup. It also does not appear to be anywhere near the inch or so of laminate that I would have expected to see.

Of the most significant concern to me would be the obvious delamination of the layers comprising the layup. That kind of delamination can result from damage or from defective materials or laminating procedure.

I suspect that it would take a fiberglass expert with the required chemical engineering background and the necessary test equipment to obtain much more than a hypothesis as to the cause of this failure.

 

[Larry14133]

The thing in the photo that stands out most to me is there are only two holes. My 302 has three keel bolts with backing plates. The plates are about 4x4". Should be three holes. Looks like the front keel bolt is was missing. Can that be?

The 302's all fly the O'Day name but they were made by several companies. Is this problem related to one company?

 

[Ross]

It appears to me that the unreinforced resin thickness exceeds the thickness of the laminate.

 

[Hermit Scott]

Larry-does your boat have a total of 3 keel bolts or 3 of a certain number have backing plates?