Keel to Hull join flaking..?

[pbyrne]

I have no idea what to call what I'm seeing.

I can't see why this is a problem, as it looks innocent enough, I tightened the keel bolts last year as well.

Why is it 'flaking' and how do I correct it?  Is there anything to be concerned about?

This has been progressing over the last couple of seasons, and did not appear like this suddenly.

[Ron Hill]

pby : Look like the faring material is flaking off now that you tightened up the keel bolts!!

I'd take a "V" type can opener and scrape out the old material and use 3M 5200 and far-in the crack.

A thought

[Noah]

  It looks pretty cosmetic to me so I would NOT recommend 3M 5200 for this.  You don't need adhesive strength in your case and it is hard to make it smooth and fair. I would just use a good epoxy fairing/filler—-that you can sand smooth and paint. If the crack was "open" and weeping or you were rebedding the keel, then 5200 is a good choice.

[pbyrne]

pby : Look like the faring material is flaking off now that you tightened up the keel bolts!!

I'd take a "V" type can opener and scrape out the old material and use 3M 5200 and far-in the crack.

A thought

Are you talking about one of those to open one of these?  LOL

[pbyrne]

It looks pretty cosmetic to me so I would NOT recommend 3M 5200 for this.  You don't need adhesive strength in your case and it is hard to make it smooth and fair. I would just use a good epoxy fairing/filler—-that you can sand smooth and paint. If the crack was "open" and weeping or you were rebedding the keel, then 5200 is a good choice.

No weeping, it's just slowing been getting worse over the last 3 years or so.  I didn't think it was anything serious, but I thought I'd ask the experts!  I looked around at other C34's in the yard and they didn't seem to be doing this.

I only tightened the keel bolts last year to 105ft/lbs (I think that's the number). I don't think it's been done in 23 years.  They weren't that bad.  One or two needed a half turn, most needed a touch to a 1/4 turn.

[Ron Hill]

pby : Yes, that's the correct can opener!!

A thought

[ewengstrom]

Sticking my nose in here simply because I do have a bit of experience with Catalina 34 keel attachment.
In going back and forth with Catalina recently I know that Catalina covers the joint with fiberglass and then a fairing compound over the glass to smooth it out. I found evidence of this during recent work on my C34.
Based on this picture, I see no evidence of the glass, only a clear line at the keel joint itself. Perhaps this boat had its keel removed sometime in its past but the joint wasn't glassed over when reattached? Or the joint was exposed for some reason and not glassed back over?
I'm definitely of the mind to remove the bottom paint and fair and putty the joint as needed. If the flaking recurs then you can consider grinding the area back and glassing the joint, but with no weeping it's definitely a cosmetic repair.
As is often said around these parts, YBYC.

[pbyrne]

Sticking my nose in here simply because I do have a bit of experience with Catalina 34 keel attachment.
In going back and forth with Catalina recently I know that Catalina covers the joint with fiberglass and then a fairing compound over the glass to smooth it out. I found evidence of this during recent work on my C34.
Based on this picture, I see no evidence of the glass, only a clear line at the keel joint itself. Perhaps this boat had its keel removed sometime in its past but the joint wasn't glassed over when reattached? Or the joint was exposed for some reason and not glassed back over?
I'm definitely of the mind to remove the bottom paint and fair and putty the joint as needed. If the flaking recurs then you can consider grinding the area back and glassing the joint, but with no weeping it's definitely a cosmetic repair.
As is often said around these parts, YBYC.

Interesting.

I'm the second owner and for the 4 years I've owned it the keel hasn't been touched other than to tighten the keel bolts, and for the other 20 years, most of that it spent on a tame, fresh water river, in Ontario Canada.

I'm 100% confident the keel has never been removed, ever, for any reason.

Unless there's a layer of fiberglass hiding somewhere the picture doesn't show, Catalina did not use fiberglass on this keel.

I can also say that there were 3-4 other C34 MKII of around the same age, where the boat used to be, and they all looked identical at the keel to hull joint to my eye.  I looked around the yard the first year this started to happen.

[ewengstrom]

I'm the second owner and for the 4 years I've owned it the keel hasn't been touched other than to tighten the keel bolts, and for the other 20 years, most of that it spent on a tame, fresh water river, in Ontario Canada.

I'm 100% confident the keel has never been removed, ever, for any reason.

Unless there's a layer of fiberglass hiding somewhere the picture doesn't show, Catalina did not use fiberglass on this keel.

I can also say that there were 3-4 other C34 MKII of around the same age, where the boat used to be, and they all looked identical at the keel to hull joint to my eye.  I looked around the yard the first year this started to happen.

That's quite interesting. My assumption came from more than a few conversations with Catalina Yachts, they sent me some very helpful info for my project and one of those items was a picture of the keel joint on a new Catalina sailboat and the keel joint was very clearly glassed over along its entire length.
When I ground mine back it too had been glassed along its entire length. My assumption was that since mine was an 88 and the photo provided was of a new sailboat that it was probably SOP at Catalina to glass the joint. Apparently that may not have been the case thru the years.

[Noah]

  No glass on my 1990 joint. Just faring.

[ewengstrom]

I was asked not to distribute the photos shared by Catalina, but here's a close up shot of the aft portion of my keel showing the glass below the joint. Your mileage (and boat) may vary.

[Noah]

Eric— there may be glass under the fairing compound but I never had to grind or dig that far. I have only a had to repair a bit of cracked fairing putty over the past 9 years. The boat only gets hauled every three years for a bottom job here in SoCal. It will be time again this October. I will see how it looks.

[Ron Hill]

Guys : On my boat 1988 there is a coating of faring? material completely over the lead keel. Maybe that coating has changed over the years and now appears to be fiberglass?? 

I believe that all Catalina lead keels have a coating on them!!

A thought

[KWKloeber]

I believe that all Catalina lead keels have a coating on them!!

When I dropped my keel there was no fairing/coating.  The only dressing was to fair the keel stub to the lead and formed a smooth "crescent" from the stub to the keel. 

You can see where the VC Tar had been applied right atop the lead and and the joint before I faired over it. 
Actually not shown yet in that pic, I did similar to the CTY fix and wrapped the jont with 4" biaxial tape.  Then faired over it.

Pic #2 is after applying the first smoothing-out coat (West + medium weight filler.)

Interesting -- my C30 keel stub was short for my keel -- about 3 inches short!!  Pic #3




 

[KWKloeber]

@pbyrne

I think you are looking at the result of freeze-thaw. 
A little water gets behind the fairing (typically from wicking down the keel bolt threads and attacking the polyester "mung" keel bedding.) 
Then it only gets worse and worse, year after year.  That's what happened on my C30, except about 1/3 of the bedding was "gone."  Not gone as in missing, but "gone" as in turned into wet mush (like wet drywall) from water leaking down the bolts to the bedding and attacking it.

I doubt you tightened the keel by torquing the nuts.  More likely you were compressing the nuts into the fiberglass bilge. 

IIWMB here what I would do to first investigate/confirm what's going on.

1) Use your angle grinder ("cheap" at Harbor Freight if you don't have one) with a 1/4" thick wheel https://www.lowes.com/pd/DEWALT-Silicon-Carbide-4-5-in-Grinding-Wheel/1207179 (buy several!) 
Using a Dremel as some typically suggest (or any other child's tool) is just wasting your time.  It's an adult job, use an adult tool.

2) At the most forward and aft points, grind away ONLY enough fairing covering the joint to expose the joint/bedding material.  It should be whiteish-gray (or grayish-white?), about 1/4" to 3/8" thick, polyester mung between the keel and stub. 

3) Snap a chalk line to mark the precise location of the joint along the keel.

4) Use the wheel sideways -- such that you grind a slot into the fairing/bedding.  NOT flatways grinding away a 4" or 5" swath of fairing.)  Lightly grind a shallow groove then keep going back over it to deepen it until you get to the bedding. Grind just below the edge of the bedding, not deep into it.

5) Probe the condition of the bedding (ice pick, thin screwdriver, etc.) to see if it is competent or if spots have deteriorated.

6) Obviously while grinding you can determine what's going on, how extensive the "peeling" fairing is, if the bond is broken and is loose, and if it needs to be ground away as well.   

7) What you discover will determine the fix -- simply filling the ground-out slot with G-Flex, or grinding off more fairing (wider swath) to wrap the joint (I used 4" biaxial glass tape/epoxy resin, but I would use carbon fiber if I did it again today.)