This crack seems to be really deep. I did not take a close look but there's no noticeable damage on the underside. I assume this is just a gelcoat crack?
Fiberglass crack by winch
- Thread starter Project_Mayhem
- Start date
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,214
Winches need adequate backing plates. Not all installs are completed with adequate backing.
Winches are sometimes used by owners to do tasks they were not designed to do.
This often shows the weaknesses of the install.
I would remove the winch. Identify the structure under the winch and repair any weaknesses discovered. Clean and patch the surface blemish's and then reinstall the winch with a strong backing plate.
One can speculate on what occurred to cause the issue. But the cause is not relevant to your needs for a strong winch on the boat.
You are not the first new owner to buy a boat only to discover hidden opportunities for improvement of the now "their boat".
On the positive, you have a nice sized self tailing winch that will serve you well in the 2025 season.
Winches are sometimes used by owners to do tasks they were not designed to do.
This often shows the weaknesses of the install.I would remove the winch. Identify the structure under the winch and repair any weaknesses discovered. Clean and patch the surface blemish's and then reinstall the winch with a strong backing plate.
One can speculate on what occurred to cause the issue.
But the cause is not relevant to your needs for a strong winch on the boat.You are not the first new owner to buy a boat only to discover hidden opportunities for improvement of the now "their boat".
On the positive, you have a nice sized self tailing winch that will serve you well in the 2025 season.
Is that winch on the O'Day 25? What's the year of production?
Lots of early boats used quite thick gel coat that would later exhibit cracks like what you are seeing. It is quite likely it is nothing more than a gel coat crack. But it is definitely worth a bit of investigation.
dj
Lots of early boats used quite thick gel coat that would later exhibit cracks like what you are seeing. It is quite likely it is nothing more than a gel coat crack. But it is definitely worth a bit of investigation.
dj
This is on my new to me 94 Catalina 30. The O'Day coamings are built like a tank. It was tested one stormy day and the winch mounting bolts failed with zero visible marks in the fiberglass. I gained a ton of respect for fiberglass that day
I'm leaning more towards this being a deep gelcoat crack since there's no cracks on the underside. A large wood backing plate isn't a bad idea for the future. Still seeking out a few more opinions on this crack
I'm leaning more towards this being a deep gelcoat crack since there's no cracks on the underside. A large wood backing plate isn't a bad idea for the future. Still seeking out a few more opinions on this crack
I prefer stainless steel backing plates - but wood would work. I've also used starboard (sorry, just realized I've used G10, not starboard) as backing plates - never used wood...
I was watching a video - don't recall the website, they do all kinds of testing of boats - and they were taking a fiberglass boat and ramming it into a rock jetty to see how well the fiberglass hull held up to serious impacts. Surprisingly well it turns out...
dj
p.s. - edited for technical clarity
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There's plenty of material options for backing plates. I figured wood or starboard might help absorb some impact. I have some marine ply scraps so the only things that I might have to buy are longer bolts
Is the area solid glass or cored there? From the looks of the crack and your statement that the underside is fine my guess is there’s rotten or at least elongated holes through a core that’s allowed the top layer to shear. If there’s no core the cracks would concern me less.
If there’s underside is still fine I don’t think a backing plate will make much difference. The point of a backing plate is to spread load so the underside doesn’t collapse under compression, but if that hasn’t happened yet I’d say the original design was good enough.
If there’s underside is still fine I don’t think a backing plate will make much difference. The point of a backing plate is to spread load so the underside doesn’t collapse under compression, but if that hasn’t happened yet I’d say the original design was good enough.
I'm not sure if it's cored or not. I cut into the coaming of an old C27 once and it had a LOT of core. Very well built. I think your analysis of this is very good, especially regarding backing plates and compression
I agree with others here that it's likely a thicker section of gel coat, and it can show a crack due to shrinkage as it ages. For a backing plate I would go with a quarter (or 3/8) inch of G10, set in epoxy mush. I had no such cracks but did that for all 8 of our stanchions and all 6 winches. Smaller G10 plates under the clutch stoppers also. Proactive beats "reactive" for stuff like this. (IMHO) And when these stressed-in-use parts are off the deck, over-bore, epoxy the holes, and rebore. Yup, we did that for 100% of our deck fittings.
You have a specific question on a Catalina, try going to the best site for yours catalina30.com good luck
This was my first thought.
Pull the winch and see what the holes look like. Drill a small (⅛") hole to examine the core. If the core is dry or all glass, then just fill the hole with some thickened epoxy. If the core comes up wet, well you know what to do.
Starboard is a poor backing material because it will compress more than the fiberglass it is backing up. Backing plates should be hard, like G10, SS, tight grained hardwood, etc.
thanks for this post - I just realized I misspoke above - I've not used starboard, I've used G10... I edited my previous post for clarity....
dj
I believe the jib sheet arrangement is like my 93 C30. The sheet runs aft from the fairlead blocks to a cheek block which is located behind the winch. The sheet then turns to the winch approaching from the stern quarter opposite from the cracks. So probably not compression related.
Since there are no compression cracks on the stern quarter side of the winch, and the cracks are the on the corner, I agree probably just gel coat cracks. I'd still grind them out a bit so water doesn't get in the cracks and freeze, making them worse.
Since there are no compression cracks on the stern quarter side of the winch, and the cracks are the on the corner, I agree probably just gel coat cracks. I'd still grind them out a bit so water doesn't get in the cracks and freeze, making them worse.
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jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,214
I would suggest if looking for a cause, that it was not sail related. Perhaps the winch was used to hual something heavy onto the boat. Maybe it was used to secure the boat to a dock during a violent storm. Maybe, as was suggested some water froze near the winch and fund an un sealed area to get beneath the Gelcoat and RFP.
What ever the case, the repair needs to assure the winch is solid and that the surface around is water proof before winter.
I would go so far as to cover the area to seal out any water exposure at least until spring.
What ever the case, the repair needs to assure the winch is solid and that the surface around is water proof before winter.
I would go so far as to cover the area to seal out any water exposure at least until spring.
This.
I crewed on a J33 in college that had similar cracks emerge around the winch. The owner sounded the core around the area and was concerned it was wet. He still raced it for a few weeks before he could get it fixed, but very gingerly in light air, and with a #3 jib only. It would be a very bad day if the winch were able to start moving and taking the deck with it.
If you look at the line stripper it indicates that the load will be on the opposite side so I agree with you all, that it's not likely caused by compression. The boat has a cover so we're good for the winter. I think I'll find a piece of scrap fiberglass to practice gelcoat matching over the winter. Any tips are welcome!