Keel paint cracking and flaking

[Damifudo]

First time sanding our new to us Catalina 30 and the bottom is in great condition untill you get to the keel. Here is the worse one but there is lots of spots that it had flaked off to the lead. https://picasaweb.google.com/lh/photo/HTkeRwEwgmo0K6ZQxfWrm8lfc-RMTflQmeP8J6ic6Mc?feat=directlink.

https://lh3.googleusercontent.com/-...JI8/7SeF07ckXUs/s640-Ic42/20160228_124904.jpg

Any advice as to what I need to do ?

 

[CloudDiver]

That's a much bigger problem than 'paint flaking'... I see fiberglass in that pic. What year Catalina 30? Had any work been done before to the keel? Did they try to fix a Catalina smile?
I wasn't aware that the keel on a 30 was sheathed in fiberglass. My best guess is that a blister formed (polyester resin is prone to osmotic blistering) and caused the fiberglass to delaminate from the keel. I'd be worried that there is more blistering elsewhere on the keel and hull below the water-line. Inspect the entire hull closely.
Good thing you are hauled out. I would suggest sanding all of the bottom paint off including any barrier coat down to the original gelcoat. Get a Surveyor or a friend who is familiar with identifying osmotic blistering, particularly someone with a moisture meter. Measuring moisture in the hull laminate is the best way to know if you are safe or not.
I've got my fingers crossed that you don't find any more than the one that is in the picture. If the moisture readings are low enough you should be fine. If they are too high, after you have sanded all the paint off let her sit for at least two months on the hard to 'dry out', occasionally rinsing the hull down with fresh water. Sounds crazy, but this helps dry out the hull so don't worry if it gets rained on.
The fix for that spot and any others like it on the keel is to sand it back, feathering out gradually. Then you can add patches of fiberglass tape with epoxy. Once your hull is confirmed dry you'll want to use 3 gallons of epoxy based barrier coat, that will cover your size hull and rudder, should give you three nice coats using a 1/4" nap roller. I like Interlux Interprotect 2000, but Petit makes a good epoxy barrier coat too... Then your bottom paint of choice.

 

[Damifudo]

Thanks for your detailed reply. The boat is an 88 and was pulled and surveyed and no issues. That spot your looking at is on the leading edge of the keel where the fiberglass is feathered onto the keel. I do believe water may have gotten under the bottom paint and and had wicked up to the area where the fiberglass and keel meet. I will be grinding the area out and filling with Marine tex. I have friend with a moisture meter and I will have him check around it before filling. The fiberglass on the haul is in excellent shape the only area there is shipping or cracking is on the lead part of the keel. Catalina has said that there is now issue to with just painting the exposed lead parts of the keep with bottom paint. I plan on sanding the area smoth and paint with bottom paint and check it again when pulled in the fall so I can see if the issue gets any worse.

from another website.
I had a the same problem on my 1998 MKII. Talked with Frank Butler...who said, lead doesn't rust...just put bottom paint over it. I can report that I've had no issues with doing just that...2 years later and all is well.

 

[CloudDiver]

That's good news... Yes, lead does not rust so all you need to do is scuff it with 60 or 80 grit sand paper and epoxy filler will grip it nicely. I wouldn't recommend Marine Tex in that application, I'm just not a fan of that product for that application. I only use Marine Tex in small amounts for minor repairs. If you have some epoxy already on hand I'd strongly suggest using fiberglass fabric to rebuild the area followed by a little fairing compound. What you will spend on the epoxy and glass tape will be a little higher cost but probably not by much than the quantity of Marine Tex you will use.
Having a friend with a moisture meter is a good deal, check several spots around the hull besides just the repair area. If your moisture numbers are in the green there is no reason to do an a 2 month drying out period, also no reason to sand off everything down to the gel-coat. You can do the repair, then just scrape any flakes and sand the bottom with 80 grit just for a good prep job and then apply bottom paint.
BTW, is you boat hauled every winter? Was it hauled every year by the previous owner(s)? You find much less osmotic blistering or high moisture readings on hulls that are on the hard every winter because they don't sit in the water for years without a break. If this is the case, and you continue to haul out every winter then doing a barrier coat job probably isn't needed. If this is your only haul-out for the next 2 to 3 years until bottom paint is needed again, I'd highly recommend a fresh barrier coat before new bottom paint.

 

[Damifudo]

I can only assume it was hauled each year from PO. The picture makes the spot look much bigger than it is. Its about 3 inch in diameter but I will fill with epoxy and some cloth. Who knows this maybe from a repair from a hit on the keel from the previous owner. Its at the leading edge of the wing keel. It will probably sit out each winter although a friend made me aware that here where we have boats that are pulled with moisture in places it shouldn't that here in Maryland where we get very cold winters caused it to freeze and subjects it to blister. You can see that over all the bottom is in excellent shape considered the age of the boat. I did not find one blister on the actual bottom and neither did the survey when it was pulled in Oct. The good thing about doing all the work yourself, you see every inch of your boat. The bad thing about doing all the work yourself is you see every problem. Its a 28 year old boat lets just assume it is either broken, about to break or you just don't know about it yet.