Catalina 30 Keel Stub/Smile

[RUSSELL]

I have known since buying the boat that at some point in time I would have to address the "smile" - the issue with the keel stub. I also have the fiberglass scrubbed off the bottom of the keel at the bow end from (I assume) various groundings over the years (I am responsible for three instances).

My plan of attack for keel stub: dig everything out around the keel bolts, sand down well, and rather than using core (or plywood ) use epoxy, fiberglass mat, roving, and cloth and alternating layers of GL 10 fiberglass sheet cut to fit (with holes for the keel bolts). Build this back until one solid fiberglass keel stub around 3/8" or 1/2" less than original level. Then obtain a piece of stainless plate, cut to fit with holes for keel bolts, place in bed of epoxy and filler, and then layer with epoxy and fiberglass cloth. Install new washers and nuts; torque after everything fully cured. Torque again after boat in water.

My plan of attack for keel stub/keel junction outside: clean all bottom paint off well; sand well, dig vigorously into crack. Do a wide area around crack. Fill crack with epoxy and filler. Apply multiple layers of cloth extended well on each side of crack. Sand smooth/fair with epoxy compound. Bottom paint.

My plan of attack for bottom of keel: clean all bottom paint off well; sand well, do a wide area around bare area. File exposed lead keel to "bright". Apply multiple layers of cloth extended well around bare area. Sand smooth/fair with epoxy compound. Bottom paint.

Quite a few Catalina folks here - anyone been down this road? If so, did you lift the engine to get to that area around the back two bolts?

Thanks.

[thatch]

I have owned my C-30 for about 7 years during which time it has been hauled twice for bottom paint. At the time of the first haul, the "Catalina smile" was fairly noticeable but not drastic. The keel bolts seemed to be solid so the decision was made to just grind out the smile and fill the void with a slightly flexible filler and then cover with bottom paint. At the second haulout, a close inspection showed that there was only a slight sign of flexing in that area. I realize that these 30 some year old C-30s probably have a wide range of smiles that should be addressed appropriately but, at least in my case the "patch" was effective.
Tom
P.S. Rumor has it that another C-30 owner is in the design phase of an internal SS brace that should go a long way toward curing this design problem.

[ndutton]

http://www.moyermarineforum.com/foru...ead.php?t=6226 roughly posts 45 ~ 60

[RUSSELL]

Thanks all. I reviewed the thread Neil referenced. That thread showed the appropriate approach recommended by Catalina, which is also what in have seen in a web search.

The approach Neil is developing is intriguing to me. I assume Neil's boat-building experience allows this insight.

Neil, even if the metal bracing you are developing were readily available to order, if that plywood core in the keel stub gets wet and rots then wouldn't there still be a problem due to side-to-side forces acting on the keel and keel bolts?

I looked at many boats in the yard yesterday. The seam is readily observed in most boats, many have a crack. The degree of the crack varies.

[ndutton]

The stainless floors are designed such that they do not contact the bottom of the bilge, visible in the picture of the patterns in place. They bear on the curvature of the hull where it turns to the keel stump. Therefore all loads borne by the stainless floors and lag bolts are independent of the plywood shoe, the reason the shoe does not have to be removed.

The curvature at the keel stump is the strongest area of the hull, designed to withstand side leveraging of a 4300 lb. keel when heeled under sail.

[jbsoukup]

I dug out all the plywood in the keel stub and glassed it in as per Catalina's recommendation. Yes, I did have to remove the engine to access the aft most keelbolt. I also left a 3/16" keel to hull joint on the outside filled with sikaflex just in case of movement in the future.
I did this in two phases-
1. removed and replaced stub around first 7 bolts (no need to pull engine)
2. pulled engine and finished the job

I was originally hoping the first part would be good enough, but there was still a little movement aft so I realized I really needed to do it all the way.

[RUSSELL]

John, any issues since?

[marthur]

FWIW: The Catalina 27 has the same smile issue. I ground out a 3/16" (or so) groove and filled it with 5200 fast cure. That has kept things water tight for more than a decade.

[JOHN COOKSON]

FWIW: The Catalina 27 has the same smile issue. I ground out a 3/16" (or so) groove and filled it with 5200 fast cure. That has kept things water tight for more than a decade.

Ditto on my Catalina 27. Same procedure same result. Mine was done by the yard but I kept an eye on what they were doing while they were doing it.

TRUE GRIT

[sastanley]

I have also done the 5200 repair on the crack. I was able to get a hack saw blade in my crack and used that as a cleaning device. After 5200, I used high-density West epoxy on the first batch to complete the repair, and then faired with low-density West. This has proven adequate...several years later, the only thing I see about is about a 1" long ripple in the bottom paint, with the initial repair probably 24" long.

I also added six 1/2" diameter lag bolts spaced roughly in between the original studs. I have not ripped the bilge apart yet..I will wait and do that when I have to also do the mast step, which seems another common failure area, or maybe some "Dutton keel floors".

Sounds like jbsoukup did it correctly!

[edwardc]

... I ground out a 3/16" (or so) groove and filled it with 5200 fast cure. That has kept things water tight for more than a decade.

Finally! A good use for that "Devil Adhesive"!!

[jbsoukup]

I just did the aft keel bolt this past winter so I won't know if I'm successful until the fall haul-out. Although there was no perceptible movement when lifted off the cradle.
After the first phase, when she was hanging on the straps, I could see just the tiniest little bit of movement (opening of the joint all the way at the back) convincing me to pull the engine and finish the job. Of course I had to wait the whole season to do it.
What Catalina doesn't tell you is that you should open the keel/hull joint on the outside (IMHO) because when the internal repair is done, and the nuts get torqued there will be some movement of the keel.
I know this because I had originally repaired my smile by using a diamond blade on an angle grinder to hog out the crack and filled it with sikaflex. When I tightend up the keel bolts after the repair the hardened sikaflex squeezed out significantly.
So if I had to do it all over again, I would
1. pull the engine (not really a big deal on a C-30)
2. open the exterior keel/hull joint (use a 1" wood chisel and hammer, so easy!)
3. use a 4" angle grinder with a diamond blade to cut the perimeter of the bilge (angle it inward, parallel or nearly with the curvature of the hull. Don't worry you won't penetrate the hull.)
4. use a long handled, sharp wood chisel to hack, hack, hack away at that nasty rotten keel stub.
5. glass it in as per Catalina's schedule. (they make 24oz. roving with mat attached for faster build-up in the stub area)

I originally used 5200 on my exterior keel/hull joint but I felt it was a little too hard/inflexible. So I cut it out, did the last keel bolt, torqued all the nuts, and then filled it with sikaflex.
Hopefully my old '77 is now as good as the newer C-30s that didn't use plywood in the stub. I can't recall ever seeing one of those with a smile.

[RUSSELL]

John, how thick was the wood core in the keel stub?

[jbsoukup]

mine had a thin layer of 'glass then two layers of 3/4" plywood, then some hard stuff that looked like sand mixed with resin which I did not go beyond, so about 1 1/2"

When I did the aft bolt, I discovered some plywood beneath that sandy layer which I did remove, making the build-up more like 2 1/4"

http://www.moyermarine.com/forums/attachment.php?attachmentid=11707&stc=1&d=1463531802http://www.moyermarine.com/forums/attachment.php?attachmentid=11708&stc=1&d=1463531825

[RUSSELL]

Thanks, John.