Keel Bolt Condition and small keel damage question

[Deven R]

Hello fellow Catalina owners. Spring of 2025 I purchased my first keelboat - a 1986 Catalina 34. I sailed her all over the North East in the summer of 2025. This is my first time having her on the hard for the winter. I was hoping I could get some insight from fellow owners about the condition of my keel bolts and a small crack I discovered on my keel. When she was pulled out of the water there was no damage on the keel at all. When I checked on her recently there was about a 3-4 inch crack that had formed on the keel (Image attached). Despite being covered, the heavy rains this fall allowed some water ingress into the bilge where about 2 inches of ice formed. I was able to easily get it out with some warm water and a butter knife, however I will definitely need to replace the bilge pump and float switch before launch in the spring. Its worth mentioning that the rusty discoloration around one of the keel bolts seems to be a stain on the fiberglass. The boat had a non-comprehensive safety survey in the spring before I purchased her and will have a full survey after my winter repairs are made. Hoping to get some advice, thanks

 

[Don S/V ILLusion]

i don’t think I ever saw a 40 year old boat with pristine keel nuts/bolts. What appears from the pictures isn’t atypical. Clean up the bolts and inspect for corrosion.
As to the “crack”, digging it out will expose whether it’s an actual crack, not uncommon on Catalinas, or just surficial.

 

[Ralph Johnstone]

Its worth mentioning that the rusty discoloration around one of the keel bolts seems to be a stain on the fiberglass.

For your own satisfaction, check out the stained nut/bolt with a magnet to see it it's SS.

 

[dmax]

They don't look too bad - as Don mentioned, they should clean right up. I would remove each nut and washer, clean all the threads and re-torque them (115 ft/lbs). Make sure the fiberglass and sealant are sound around each bolt- if not, make it so. Keep in mind that a 1986 has plywood sandwiched in the fiberglass where the keel bolts come through - if water gets in there, the plywood turns to mush - it's a good size job to repair. Signs of this are the nuts on the keel bolts will sink into the fiberglass and you'll see brown staining on the outside of the keel - yours looks ok. Regarding the crack on the outside, it's common for the keel to fiberglass joint to open up - on Catalinas, this is usually caused by improper blocking of the keel when on the hard (see the manual on how to block). It's hard to tell from the picture if the crack is at the keel to fiberglass joint - generally cracks at the joint are in a straight line, yours isn't. You should remove as much as can around the crack and dig into the keel joint if it's exposed like a good 1/2 inch or more. Fill with 5200 and smooth it, paint and you should be all set.

 

[dlochner]

Not related to the cracks and the keelboat there is a serious flaw in the bilge pump installation.

The butt connectors are not water tight. This will lead to water intrusion and corrosion on the wire and eventual failure. This is also a source of stray current corrosion as DC current leaks out of the unsealed connectors. The connectors should be adhesive lined heat sealed connectors.

 

[High Current]

Missed this until now!

First of all, congrats on obtaining an excellent boat. I love mine!
Second of all, I strongly suggest you join the Catalina 34 International Association (c34.org).

Third, I know more about our keel and keel bolts than I care to remember. Check out my keel re-bedding saga here: Keel Bedding Survey

The crack merits some further investigation. It could just be the "Catalina Smile", but it does appear to have been weeping. Once freezing risk has passed I would put some water in the bilge and wait a few days to make sure it's not seeping out from above (the problem I had). As dmax says, early C34's used a plywood core that can be an issue if it hasn't already been fixed (see: https://c34.org/wiki/images/6/62/CTY_Pre-1988_model_Keel_Stub_Repair_-_Feb_1996.pdf). If the crack stays dry, I would probably grind it out a bit to be sure it's nothing major, then patch with tape or G/flex, check your keel bolt torques, and go sailing. Also make sure the bolts are properly bedded/sealed against ingress from above.

It's hard to truly judge a keel bolt from the top like this, but I'd say your pictures give me little cause for concern. The one that's weeping rust merits some further investigation, as do the aft ones buried in engine grease. I found several of my nuts and washers badly corroded, but the threads on the bolts seemed fine, and when I dropped the keel the bolts were all nearly pristine. I suspect maybe Catalina used 316 SS for the bolts themselves and 304 for the mounting hardware?

I ultimately made the decision to drop my keel mainly because water and antifreeze had clearly saturated the bedding between keel and hull. I could neither get it dry nor trust that I could properly protect it from ingress above or below. I was concerned about both freeze damage and crevice corrosion. But dropping the keel opened a can of worms I'd rather not repeat. If you do have to go that route, use a good yard and make sure they properly cut the keel away from the hull before dropping it.

 

[Deven R]

I appreciate all of the replies. I have a list about the length of my arm that I need to bang out before she gets launched in May!

The one that's weeping rust merits some further investigation, as do the aft ones buried in engine grease

How should I further investigate? There doesn't seem to be a thorough way to do this without removing the keel, which I'd rather not do. I did fill the bilge with antifreeze about 2 weeks ago when I first posted this I checked on the boat a couple days ago, it was hard to tell if any of it was weeping from the crack as there was water all over the hull from snow melting off the tarps on deck. Its a bit too cold out recently to do any fiberglass work. I will be digging it out before I redo the bottom paint as soon as the weather warms up. Its worth mentioning that the crack is only on the port side.

 

[Steve_Catalina]

On the c34 the front portion of the keel should definitely be blocked so there is more pressure than the aft section. That area of you keel in question I'd had to determine if it's more fairing compound or what. Definitely follow High Currents suggestion ad check out his c34 link. Good luck

 

[Deven R]

I looked over his c43.org link. The keel removal and rebedding looks like a headache and half. Seems like you could easily do more damage than repairs dropping the keel on these boats. I am hoping its just a blister.

 

[High Current]

I appreciate all of the replies. I have a list about the length of my arm that I need to bang out before she gets launched in May!

I know the feeling. Just remember: she's a well built boat and won't fall apart if some of it has to wait until next year.

How should I further investigate?

I simply meant you should unbolt the nut and inspect the washer and threads on any that look suspect. This could even be done in the water (one at a time). Based on my experience the studs are probably fine, but anything that looks like this should be replaced...

The encapsulation over the washers is just gel coat. It is brittle and should break away easily if you pry them up. In fact, it's probably doing more harm than good anyway since it can promote crevice corrosion.

 

[High Current]

I looked over his c43.org link. The keel removal and rebedding looks like a headache and half. Seems like you could easily do more damage than repairs dropping the keel on these boats. I am hoping its just a blister.

Yes indeed. Not a decision to be made lightly. It doesn't look like "just a blister" but that doesn't mean it can't be repaired with the keel still attached.

The damage in my case was primarily because the yard didn't cut away enough material before attempting to drop the keel.

 

[Deven R]

Im back at the boat. After grinding out the crack, it was indeed coming from the keel joint. I let it sit for about an hour and when I came back more water had seeped out of the crack. I believe it is coming from the bilge at this point. Does this warrant dropping the keel to inspect and rebed? What say the forum?

 

[jssailem]

Rather than continuing to grind down the keel, I think I’d drill holes beneath the area you are squeezing to see how far the moisture has traveled. A 1/4inch hole can be set up to suck the moisture out of the keel with a small pump. Something like a fish tank pump with a 1/4” diameter clear hose would work.

It will also let the moisture drain from any pockets.

It looks like when you press against the keel you are squeezing a fluid out. What does the fluid smell like?

 

[High Current]

Depends how invested you are in this boat. Dropping and re-bedding the keel is probably a $5-10k project. I would consider it preventive maintenance to protect the keel bolts against corrosion, not must-do safety-critical. From what I've read, IF the bolts are corroding, the boat should give you plenty of warning before anything catastrophic happens (widening seam, leaks, repeatedly loosening keel nuts). Consider also, before you drop the keel, what you will do if you DO find a corroded bolt; having Mars cast a new one is going to take a lot more time and money, and sistering is no walk in the park either. You might be better off not knowing and just sailing the boat until it becomes a problem.

Honestly, your post-grinding picture looks OK to me. There was tape / fiberglass around the keel seam; since it was cracked, water got in. Where you're squeezing is water is trapped between that glass and the keel *below* where the keel meets the hull.

Before I decided to drop mine, I was just going to re-bed the keel bolt washers with 4200 and seal the seam from the outside. Then it became clear that the whole seam was wet / saturated and wouldn't dry any time soon. Between that and the condition of my hardware, I decided to take the plunge. I'm the kind of person who would have worried too much if I didn't, and I plan to invest in and keep this boat for the long haul. If I had it to do over, I would do it again, but I'd make sure the yard didn't screw it up this time

 

[Scott T-Bird]

I believe it is coming from the bilge at this point. Does this warrant dropping the keel to inspect and rebed? What say the forum?

I suppose I would try to find out if water weeping is localized or consistent across the entire keel joint. You could remove material along the entire joint and inspect first. How many bolts do you have and what size are they? Where is the crack located and where are keel bolts relative to the crack? I wouldn't bother restoring the old nuts and washers. Just buy new ss nuts & washers (make sure you get the good quality - I found that my existing nuts were good quality ss but the washers were junk and the reason for corrosion stains). I would re-torque all bolts and then observe for inspection before I considered dropping the keel.

I replaced washers & nuts when I torqued them last winter. Mine are super hefty 1" bolts so the socket had to be 1-1/2". The torque is based on the bolt size and material. 1" ss bolts are torqued to 235 ft-lbs if memory serves. Without a partner to help me, it was near impossible. Similar sized boats seem to have much smaller bolts, so I didn't understand why I had 1" bolts, but they do help me sleep a lot more soundly. I'm wondering if Catalina was just ultra-conservative with my model or if yours are the same size.

 

[dlochner]

The question about proper torque for keel bolts comes up frequently. There are 4 factors to consider, whether the torque is for a dry unlubricated bolt or a lubricated bolt and the torque for the bolt and the torque value for the material being compressed.

Across the board for all of its boats, Sabre recommends 90 ft/lbs for keel bolts. At values higher than that the fiberglass between the bolt and the keel becomes excessive and lead is a pretty soft metal,higher torque values may distort the lead.

Following the manufacturer's recommendation for torque values is a more prudent path than relying on torque values for the bolts themselves.

 

[clublunasea]

Hello Hunter owners
I have had a 1984 Hunter 34 for 22 years. On inspection of the boat post winter, i did notice some small rust on the keel, starboard side, from a blister at the top of the keel. Any suggestions on what specific products to grind out the blister. Yard suggested a Dremel, but the blistered piece is closer to one to two inches total. No rust on the port side. Yard also suggested tightening down the bolts while on the hard before any new glass work. Thoughts.

 

[jssailem]

The Dremel is too small a tool. This is not "delicate surgery".

A hand-held mini grinder
\

Or a small-width belt sander


Using an 80-grit belt or wheel will make quick work of opening up the blister and setting it up for some thickened epoxy or fairing compound and barrier coating. Then you can paint over that with your bottom paint, and good to go back to sailing.

At least that would be my approach based on what you describe.

 

[Davidasailor26]

I agree with @jssailem - for a couple spots that size I’ve used 60 grit paper on a random orbital sander, but an 80 grit flappy disk on a grinder or mini belt sander would work too. From the pictures I’d assume this is just localized spots on the keel surface where the coating has failed, so sand to clean metal, apply new barrier coat and paint, and go sailing. If you start sanding and it does turn out the bolts or seam are involved that may be a different story, but I’d be surprised if that’s the case.

 

[Deven R]

Hello again everyone. In my quest I discovered that the wood in my keel stub was rotten after I went to torque the nuts and several of them bent the washers and sank into the laminate. I undertook the massive task of removing all of the wood in the keel stub (along with the glass-like glue they used to secure it in place) using a combination of an oscillating multi-tool, a handheld belt sander with 36 grit paper, an extra long chisel I fabricated out of a crowbar, and many prayers. I physically could not access the aft-most bilge compartment or the wood under the mast compression post but I am confident that they are still structurally sound.

After drying the bilge thoroughly for several days using a heat gun, I laid down 3 alternating layers of 1.5oz mat and 24oz roving in each compartment for a total of 6 new layers of glass, as per Catalinas spec. I differed from Catalinas service bulletin in 2 places: Catalina calls for the layup to lap 6" onto the sides of the bilge walls. The first layer I laid up I used 6", then the next layer 8", and finally 10" such that there is now much more surface area that is being bonded to. Also, I tied the new glass laminate fore and aft into the stringers with 2 alternating layers of mat and roving in between layers of the side-to-side layup.

I used vinylester resin for its superior water resistance and strength compared to polyester while retaining similar flexure characteristics, unlike epoxy. Once that was complete, I stacked 2 - 1/2" plates made of high density fiberglass board (sourced from a nuclear submarine at GDEB) on top of each other glued with structural bonding compound to float the bilge floor back up to where it used to be and provide a rock solid plate for the washers and nuts to grab. I did this step without using wax or PVA on the topmost layer of vinylester laminate such that there would be a chemical bond created between the lowest layer of bonding compound and the resin. Peter at LBI Fiberglass in Groton CT was integral in formulating this plan and walking me through the engineering. I would highly recommend them for all things fiberglass. I cannot thank him enough

This project took about 10 days of cutting, sanding, scraping, chiseling, shaking my fists at the sky, cleaning, drying, and fabricating. It took about 2 days from the time I started laying glass to completion. I am very happy with the results. I have yet to paint out the bilge in white gelcoat but I can do that in a bit. I wanted to write this up for future owners, I know it has been done before but every account of the process is integral to the next persons decision making. Attached some pictures of the process and the 99% finished product before the gelcoat goes on.

Products used were all sourced from LBI

• 1.5 Gallons 345 Structural Bonding Compound
• 1 Gallon 902 Vinylester Resin
• 6 yards of 1.5oz mat
• 6 yards of 24oz woven roving
• Fiberglass board
• Sawblade to cut said fiberglass board