Advise with purchasing/owning ferrocement boat

[Bobobolinsky]

I contributed this on a previous thread. A shortened extract:

"The problem with any ferro-cement hull, particularly an amateur build with no provenance, comes from the difficulty of knowing if the critical mixing, pouring and setting techniques have been correctly observed and that's after an adequate steel frame and ribs have been properly welded up. Most importantly, that the mix is applied evenly, internally vibrated through for the team of expert plasterers to fair the hull with sufficient layer over the steel mesh and framing - and all in one application. Only a sectional destruction test will assure that was complied with and that there were no voids - in that section."​

If you read the entire posting you will see that a professional build does not guarantee correct construction.

If the boat has been sailing around the sea for 30 or 40 years and is still in good condition, however it was built' is no longer applicable, it's fit for purpose. Usually the bad ones are artificial reefs. I nearly bought a mobo hull last year, the boat yard had hired a guy to break it up, manually and he had not made a dent in it with a sledge hammer and a stihl saw. I offered a £1, but he refused.
The only hull I have seen broken up, a team of proffesional concrete busters came in with a mini digger with a giant stihl saw and a cutting jaw. It still took two days to demolish it. If there is any rust leaking trough the cement, walk away. Lots of the ferro's are wooden topsides and it is more likely that they are rotted than the hull structurally unsound.

 

[alant]

Read my posting - referenced above in post #17 - here.

No amount of anchors would have helped, she was lying over on her bilge on solid rock shelves that ran well out with rocky outcrops. A rising, onshore wind was bringing rollers in and the pounding soon broke the watertight integrity long before she could have refloated - they were lucky to have been able to wade ashore.

From what I remember of the report, they left the boat on a boulder beach & when the tide came in, it pounded on these. Suggestions were made that it would have been sensible to inflate the liferaft under the side, to protect it.
I saw it at Earls Court - think it was outside & looked a good build.

 

[BrianH]

I saw it at Earls Court - think it was outside & looked a good build.

It may have looked good but instead of pouring the mix internally and vibrated through to be externally plastered, as the classic procedure dictated, mix was applied to both sides and, as I found from a complete hull specimen at the wreck, did not even meet in the middle, let alone bonding.

This is the point I wanted to make - only a destruction test on a completed hull can determine if it was built correctly. That one did have a destruction test and it wasn't.

From what I remember of the report, they left the boat on a boulder beach & when the tide came in, it pounded on these. Suggestions were made that it would have been sensible to inflate the liferaft under the side, to protect it.

This is the area at about half-tide, beyond the pier, the wreck was about in line with the lighthouse apex mid-bay. It is a dangerous area at the best of time and anyone with local knowledge kept well clear of it. Sadly, the new owner didn't have that local knowledge.

Whitby, unusually for the east coast, points due north and vessels approaching from the south can be misled to take a direct line towards the east pier instead of keeping well out, past the rock buoy and until the entrance bears due south.

Once the tide starts coming in, lifting and dropping a heavy hull repeatedly on rock scars for a few hours, I wouldn't expect a lashed liferaft to stay conveniently in place. It wasn't just a boulder beach, it was flat solid rock with scattered boulders and it was dark with a rough sea. No place to be in such conditions.

 

[davidfox]

Very good thread, I have heard the stories about ferro like everyone else, but I have never actually come across a bad one, i have sometimes admired a craft only to be told, 'she's ferro you know' so i assumed that they were rubbish, because everyone said so. Very pleased to be put straight. Its probably the same people that say bilge keelers are rubbish and dont sail well, having had both i would disagree with that statement as well.