Hull Crazing

[hebert01]

Hey all-

I remember reading about this type of problem earlier, and I believe the problem was discussed here - complete with pictures similar to my own. Unfortunately, I'm having a hard time finding the specific discussion and visuals in my search, so I'll ask again.

I'm in the process of stripping my bottom paint on the Ensign, and have uncovered what I believe to be hull crazing typical of early-era FRP boats. But in discussions with some other Ensign owners on the Yahoo Ensign board, they've got me spooked that the crazing is something more substantial than I am concluding. I did some moisture measurements and all is dry. Boat's been on the hard since October. Did the moisture measurements sometime around November.

Can you please take a look and let me know whether this type of crazing is typical of ca. 60's Pearsons?

Thanks

[triton #227]

My triton looks just like that I thought it was from the 10 layers of old paint. after sanding down a spot there is no crazing in the orignal gelcoat.

[Case]

That crazing is fairly common to older fiberglass sailboats built in the 1960s. The most likely reason is... the gelcoat was either too thick or too brittle or a combination of both.

I think its a minor issue. Ugly, yes but still minor. I don't think its worth stressing over about. Paint over it and don't worry about it. What kind of bad things did the Yahoo Ensign board mention about this? I'm interested to know.

I compliment your taste for getting an Ensign. I love them and I happen to sail the Ensign's older near-sister, a Sea Sprite 23.

- Case

[Tim]

That's nothing to worry about whatsoever. Rest easy.

[Quetzalsailor]

Seems to me that I read somewere, so it must be true, that you should sand the crazed material off and commence refinishing from sound, uncrazed material. There's no structural issue with that sort of generalized crazing, but it may compromise subsequent finishes.

Having exposed the surface, can you read patterns in the overall crazing that you can relate to stringers or bulkheads, or can you see bullseye patterns that would form around an impact? These might well deserve further attention. Examples that I was quite familiar with, and ignored since I was not refinishing, include the longitudinal crazing in the sidedecks of my Morgan 27 associated with the inboard deck-mounted chainplates and paralleling the longitudinal folds in the deck shape (I did restructure the boat so that the chainplate loads were transfered to the hull; after that, the deck no longer lifted when the boat heeled), and the two foot diameter bullseye in the bottom where the boat had been dropped in its cradle (the cradle pad did not end up under a bulkhead on starboard, like it did on port).

[hebert01]

Case- The Ensign board is concerned with it being osmotic blistering. They're suggesting major grinding, filling, fairing, barrier coating. I don't think that osmotic blistering is the case here - at least not in the classic sense that I've seen. BTW, I love the Sea Sprite too. My "next door neighbor" at the mooring in a SS23 owner. His SS and my Ensign look mighty nice sailing side by side.

Quetzal - No correlation I can see of the crazing to structural members or impact. The entire underside is uniformly afflicted. Also, the crazing is all sanded flush, and I'm hopeful that it'll cover uniformly. Now whether there's any movement after the fact (due to moisture or thermal effects) remains to be seen.

Tim - Thanks for the vote of confidence. I remember you once wrote that even in its worst case, the number of sunken boats or deaths due to blistering is pretty low. That logic is pretty tough to argue with.

[Rachel]

From the photo, that doesn't bear any resemblance to osmotic blistering (as others have mentioned).

I had the pleasure of sailing with some friends on their Ensign in Casco Bay a few summers ago. What a fun boat! I loved that you sit in the boat, not on it, and it gave me a real appreciation for "non-self-bailing" cockpits.

Rachel

[Tim]

Case- The Ensign board is concerned with it being osmotic blistering. They're suggesting major grinding, filling, fairing, barrier coating. I don't think that osmotic blistering is the case here - at least not in the classic sense that I've seen. BTW, I love the Sea Sprite too. My "next door neighbor" at the mooring in a SS23 owner. His SS and my Ensign look mighty nice sailing side by side.

Quetzal - No correlation I can see of the crazing to structural members or impact. The entire underside is uniformly afflicted. Also, the crazing is all sanded flush, and I'm hopeful that it'll cover uniformly. Now whether there's any movement after the fact (due to moisture or thermal effects) remains to be seen.

Tim - Thanks for the vote of confidence. I remember you once wrote that even in its worst case, the number of sunken boats or deaths due to blistering is pretty low. That logic is pretty tough to argue with.

You don't have anything remotely related to blistering going on there. And you will never have real blistering on that boat. Those cracks won't become blisters, they won't encourage blisters, and they aren't the sign of hidden damage. They aren't even stress cracks: they're simply crazing cracks related to properties of the gelcoat, and are not only common in old Pearsons, they're nearly universal. I'd wager that those cracks have existed in their current form for most of your boat's life, without change.

Being able to identify real problems, and then deal with them--while not worrying about things that need not be worried about--is an important aspect of working on any boat. Those that would have you be grinding all that away clearly don't understand the nature of those very minor, tight gelcoat cracks. It's critical for one's own good--and the good of the boat--that one understands enough about various situations to make informed decisions in the face of the often uninformed and breathless fretting perpetuated by many.

[Tim]

Oh, and don't barrier coat it "just because" either. I've covered my reasoning behind that in several other posts on this forum in the past.

[hebert01]

I'm firmly in your camp when it comes to barrier coat. In fact, this whole discussion came about on the Ensign board as a result of me offering advice to another Ensign owner that had questions about the same problem. After others disagreed, I figured I check in here for a second opinion, to make sure my advice to the other owner wasn't off base. Here's a cut/paste of my recommendation to the other owner.

While #998 has the same spider cracks you see,
there's no evidence of moisture in my hull. Moisture meter readings
have shown no measurable difference between moisture in my hull and
topsides - the hull is dry. I've opened some of the cracks for visual
inspection, and thankfully no voids or damage. "Tap testing" the
rest of the bottom with a screwdriver handle hasn't uncovered any dead
spots or voids either. Believe me, the cracks had me concerned, so I
spent a bit of effort trying to understand it. I agree that it's
visually not attractive, but beyond that I'm comfortable that I don't
have a significant moisture problem.

I'm personally of the belief that moisture barriers aren't always a
cure-all. They can help hulls with existing blistering problems, but
they can also act to keep water in the hull as well as they keep it
out. So I tread cautiously in upsetting a structural system that seems
to be working OK. Since I don't seem to have a quantifiable problem
with moisture ingress, I'm not comfortable establishing a barrier to
prevent its possible egress. But if I had the classic blisters, I
would act accordingly.

A lot of my understanding of my boat comes specifically from reading and asking on this board. I think there's a lot to be said for "measuring twice and cutting once". And when it comes to this particular "problem", doing the necessary research or asking the questions before plugging in the grinder has just reassured my judgment - and saved me a ton of time and money. So, in case I hadn't said it in a while - thanks again, guys/gals!

Incidentally, for those interested in viewing/contributing to the original discussion, it can be found at http://groups.yahoo.com/group/EnsignSailors/message/152 The Ensign board is relatively new, but may be of interest to those with issues specifically concerning Ensigns.

[Tony]

Ed,
Look on the bright side, Now you can find a good voodoo witch doctor who can read your boat's future in the cracks of the gelcoat :-)

[keelbolts]

And Tim sayeth:
Being able to identify real problems, and then deal with them--while not worrying about things that need not be worried about--is an important aspect of working on any boat. Those that would have you be grinding all that away clearly don't understand the nature of those very minor, tight gelcoat cracks. It's critical for one's own good--and the good of the boat--that one understands enough about various situations to make informed decisions in the face of the often uninformed and breathless fretting perpetuated by many.

That reminds me of something I read a boat builder say. He said that the difference between a professional and an amateur is that a professional knows good enough while the amateur consumes vast amounts of time/effort/money grasping at perfection.

All kidding aside, this is one helluva great place where you can bring a problem that's keeping you awake at night and get a reassuring answer form such a knowledgeable bunch of men and women (woman?).

[jlroberts280]

My boat has this same issue. If you were going to paint it would you try to fill the cracks with fairing material or would primer take care of covering/filling these cracks?

[Tim]

My boat has this same issue. If you were going to paint it would you try to fill the cracks with fairing material or would primer take care of covering/filling these cracks?

Are you talking about in the bottom, or on the topsides above the waterline? My answer is very different depending on which.

If the bottom, the answer is already written above. But before I write about topsides, I'd like to be sure that's what you meant.

[One Way David]

Tim, for the sake of learning, could you answer as if he meant topsides. I'm soon to be doing just that and would like to know.

BTW, I got flamed bad in a Board meeting once for saying something about a group of board members acting like a bunch of cackling hens. Could I borrow your comment above,
"It's critical for one's own good--and the good of the boat--that one understands enough about various situations to make informed decisions in the face of the often uninformed and breathless fretting perpetuated by many." ;)
Dave

[jlroberts280]

Sorry if I was not clear. My whole hull, above the waterline looks just like the picture that started this thread. The boat has never been painted.
I bet the hull below the waterline looks like this also but I have not removed all the bottom paint to see it. And, I dont think this is in the near future.
The deck has areas of cracking/crazing but they are concentrated in stress areas like by the chainplates and the areas where vertical meets horizontal areas like the cabin sides meeting the deck.

I am interested in painting the hull at some point and was curious how far down I would need to sand to achieve a decent finish and if these cracks would need to be filled by more than primer. I would be curious how/why your answer would change if I was talking about the deck. Sorry if this has been addressed before. If it matters I would be applying the primer and paint by roller and tipping off vs, spraying.

[Tim]

It sounds like there's a little confusion. "Topsides" are the portion of the hull between the waterline and the gunwale, so I wasn't talking about a difference between how I might address the deck or the topsides, but between how I would address (or not) the bottom or the topsides. As a post of mine earlier in this thread indicates, I would leave the bottom as is and paint it over that sort of cracking.

For the topsides (that is, the hull above the waterline), high-build primer, properly applied, will hide the thinnest of crazing, but doesn't hide thicker cracking--at least not for very long-term. These will tend to print through eventually. However, when determining how to proceed in a painting process, one also has to determine to what extent they really want to go in attempting to remove all-over cracking/crazing, whether it looks like that in the photos above or is more severe or otherwise different.

The only way to ensure (inasmuch as anything can ever be ensured) that all-over cracking or crazing doesn't reappear within an unreasonable amount of time is to remove or encapsulate the areas that have crazed/cracked. Removal generally entails grinding or peeling the gelcoat off the boat, and sometimes part of the skin laminate beneath. Obviously this is a big, time consuming, expensive job. But for the barely-visible type of cracking seen above, this approach would be overkill, I think.

Some of the gelcoat cracking that occurs on these boats is so bad, and so extensive over the entire surface, that full gelcoat removal or encapsulating (in a new layer of fiberglass, which then requires filling and fairing to achieve a smooth surface) are the only answers, unless one can accept the fact that the cracking will always show through the paint.

If I were faced with the gelcoat appearance seen above--which is minor, thin crazing--I would heavily sand the surface to minimize the cracking, but would stop short of attempting complete removal. This means 40-80-120 grit sanding. The extra effort to completely remove the gelcoat layer just doesn't make sense in a situation like that in the photos above. Sanding through the grits, spot removal of areas with more significant cracks (and subsequent filling/fairing), and then proper application of high-build and finish primers will take this sort of surface to a 90% or better level of achievable perfection.

Let's face it: the hulls and decks of old fiberglass boats are never perfect to begin with. The tooling and molding just wasn't perfect at the time of construction, and the boats tend to have plenty if imperfections in their basic form already. So even a "perfect" paint job isn't, really. One just cannot fix all these flaws within anything resembling a reasonable amount of time or within a reasonable budget. Sure, it could be done, but it would be very expensive (in time and/or dollars).

One has to pick one's battles, however. One has to do the best they can in any given situation, but one must also understand the limitations against which they are working, whether that means the boat itself, the products chosen, or one's own skill.

The long and the short of all this is that for cracking like that seen above, a through preparation that includes high build primer will provide a surface suitable to achieve a satisfactory final result.

[One Way David]

Thanks. Tim, if you haven't or aren't already, you should write a book. I know, I'm old school and still read the printed page but you could do an e-book version. I know, some would argue that this is a book edited, if not completely written by you. The search engine is wonderful but does not completely replace an organized presentation, especially for the novice. There is a lot of fodder here that your insight, wit and style could turn into many enjoyable hours of reading. Just a thought. Dave.

[jlroberts280]

Thank you