You can fill the crack all you want but it will keep coming back. You need to grind back 2 or 3 inches on either side and then use cloth and epoxy and finnally filler to smooth it out.

I need to go and grind my smile out in the next couple of weeks.

Capitain Cure,

I am confused, what you discribe is not what is refered to as the Catalina smile if I understand what you are saying. I would sound like you have sepration or gap at the keel to hull joint. If this is the case you are on the right track to rebed the keel.

The Catalina smile to my undersstanding is a distortion that can form in the hull forward of the keel when the boat is not blocked well. If you have a crack in this location you have a much more significant repair to address, I doubt this is what you are doing.

There is another form of the Catalina Smile as well, I usually get one when on a screaming reach.

Steve

Cure sir,

I do not believe that Catalina ever used wood between the keel and hull. There is wood in the frames above the keel to stiffen the structure.
The cracks emanating from at the leading edge of the keel outboard and up if just in the gel coat it is not a big deal. If it is in the underlying structure this is a horse of a different color.

I suggest you let more members weigh in on this issue. I may also suggest you touch base with Catalina if this is beyond the gel coat level. As this is a high stress area on the hull.

My guess it is just a gel coat issue and the advice you have recieved here regarding this looks sound.

The Catalina Smile is where the keel starts to seperate from the hull. It usually starts at the forward end and works back. There are a number of possible causes. Loose keel bolts, improper blocking or stiking unseen under water objects...... The same issue is common on a number of simmillar yachts... Hunter smile comes to mind.

I am not sure on the plywood filer and when it was used on the 36 but it was also an issue on the C30. Plywood was used in the bilge to build up the thickness and supposidly add strength. A couple of layers of fiber glass then sealed the bilge and nuts and washers were put on. Wood ROTS and compresses. This will cause the keel bolts to loosen and the keel will move and the smile will begin....

You are right to tighten the keel bolts while on the hard with the load of the boat on the keel. To repair the smile grind it out as I mentioned before. Seal the crack and then build up a 2 or 3 layers of cloth and epoxy, then fair the seam out to make it smooth and pretty.

You can do a test drill into the bilge with 1/4" dill. If you go down a inch or so and it is still fiberglass nothing to worry about. If you hit solid fir plywood not much to worry about. If you find mushy rotten wood, the fun really begins..... It is not pleasant and is a lot of work.:(

Re tightening keel bolts...make SURE you do NOT over-torque. Full instructions elsewhere on this site.

So I spent the weekend working on my Catalina smile. We had about 1' of cracking both sides along the front of the keel hull joint. Ground out a V groove, filled with epoxy etc.

Then rather than try to find a ridiculously deep socket to put on the keel bolts, I cut the heads off the studs so that a standard 1.125 socket will fit on them. Big job - the forward one I could just get with an angle grinder but the next two aft of the mast took a long time with a dremel tool and about 12 cutoff wheels. I note that it is impossible to get a visual on the starboard bolt right aft of the mast.

I then discovered that the most forward stud was seriously wasted inside the nut. The others appear OK. I stacked about 3 washers under the front one and refrained from getting really carried away with the torque, but brought the next two right up to full welly.

Next day smoothed out the epoxy and faired it with vynilester fairing compound. I did not have time this go round to wrap it in cloth - cracks will probably come back.

However, the excellent outcome is that I spent so long f'cking around with the keel bolts that by the time I came back downstairs my wife had painted the entire bottom of the boat! Score.

[QUOTE=Nimue;20207]I stacked about 3 washers under the front one and refrained from getting really carried away with the torque, but brought the next two right up to full welly.[/QUOTE]

I learn something every day, Jason, and today was the phrase 'full welly.' Never heard that in my 56 years, but I haven't lived outside the US, either.

Hate to give the Brits any extra credit but when it comes to descriptive slang they are tough to beat.