Ferrocement! Why not?

Discussion in 'Materials' started by MarkOHara, Oct 14, 2023.

  1. MarkOHara
    Joined: Oct 2021
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    MarkOHara Junior Member

    When it comes to boats/barges that are mainly stationary on the inland waterways why isn’t ferrocement a popular option?
    Sure it may have condensation issues like Steel & GRP, but it doesn't deteriorate like a steel hull, or flammable like GRP, or rot like wood.
    Sure it may be heavier and take a higher HP to push but what's the issue if it's mainly stationary?
    Sure it may have less freeboard and carry less of a load but why would that matter if it's a houseboat?
    Most Widebeam & Barge conversions have to be heavily ballasted anyway if converted to accommodation.
    What's your opinion?

    Link to Ferrocement build on Flickr Ricky's Ferrocement Barge https://www.flickr.com/photos/dennisgsy/sets/72157627316275915/
     
  2. skaraborgcraft
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    skaraborgcraft Senior Member

    Seen at least 4 plastered as a kid, as my uncle owned one for some years and was part of a plastering team. Fast forward 25 years and i bought a Hartly Tasman 28 Ferro hull that i fitted out and rigged, and then cruised from the UK down to the Med via N.Spain and Portugal. Had a cleat ripped out the foredeck while in a fishing harbour due to over speeding fishing trawlers, but easily repaired in an hour with some spare wire mesh and a bag of cement. If they are built right to start with, they make very good boats. If they have sub-par material and badly plastered, they can be a liability waiting to happen. Most of the crap ones are pretty obvious today with blown cement. There are still concrete lighter barges used on the Thames that were built during WW2, as they were faster and cheaper to build than wood. Its labour intensive, but materially cheap.
     
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  3. wet feet
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    wet feet Senior Member

    Try insuring one.Alternatively,consider the liability taken on should you seek a berth in a marina with no insurance,not that any are likely to accept an uninsured boat.It was this aspect of boating that killed off a medium that had been adopted by amateurs seeking a cheap boat.The material could actually produce a decent boat but as it was so popular with novice builders and they made a sufficient percentage of errors that led to the reinforcement corroding and damaging the integrity of the hull,which brought about the disfavour.Once completed it was difficult to sort the wheat from the chaff.I don't know if recent developments in technology have made it possible to assess the integrity of the finished hull.
     
  4. gonzo
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    gonzo Senior Member

    The reinforcement is steel and it does corrode. Considering that the hull of a recreational boat is usually no more than 10% of the total cost, it doesn't make much sense. It will be difficult to insure and even more to re-sell. For a floating dock or barge, it may be OK.
     
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  5. Barry
    Joined: Mar 2002
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    Barry Senior Member

    There is no doubt that the design and proper build process between a stationary concrete structure and a boat is completely different.
    Evidenced by the numerous foam filled concrete floating docks around the world.
    So your comment that "why isn't ferrocement a popular option? Well it is for floating stationary structures
     
    Last edited: Oct 14, 2023
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  6. skaraborgcraft
    Joined: Dec 2020
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    skaraborgcraft Senior Member

    Third party insurance is no problem, its all i have ever had on all the boats I have sailed. Full insurance is like people who drive Volvos, they put themselves into positions that might not usually consider.
     
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  7. philSweet
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    philSweet Senior Member

    The US Coast Guard won't even look at one, so you can't get it approved for anything at all.

    Queen Anne's Revenge II.
    [​IMG]


    This ferro boat had a wonderful history including Sea Scouts in the Florida Keys. For about a decade, she was a bandit tour boat. She wasn't inspected or licensed, but if you ate dinner at the restaurant, you got a "free cruise" - assuming somebody turned up that could sail her. Sometimes that was me.

    upload_2023-10-14_14-10-41.jpeg
     
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  8. kapnD
    Joined: Jan 2003
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    kapnD Senior Member

    We don’t see much ferrocement building going on nowadays, it’s popularity has definitely passed, but I wonder if more modern materials might make it a more feasible method than it was in the past?
    Epoxy mortar additives and fiber reinforcement could yield a much stronger product, and epoxy coating for the surfaces.
    Fiberglass reinforcing rods are now available too, as well as various fiber mesh materials to make the rust issues go away.
    No, I’m not going to build one!
     
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  9. comfisherman
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    comfisherman Senior Member

    Have records of family boats built from the late 60s until 2019. My grandfather built a fiberglass boat in 71 and three drums of resin cost as much as the main. Fast forward to 2019, I could have built 3x hull decks and cabins for the cost of my main sand installation accutremonts. Reality is as gonzo pointed out hull cost is 10 or at most 20% off the cost of even simple voluminous commercial craft. So if you save 50% on material cost it's not gonna change the total very much.
     
  10. Rumars
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    Rumars Senior Member

    Ferrocement is actually very difficult to do well. It requires a very skilled workforce beginning with the engineering and ending with the plasterers. A good hull should be indistinguishable from a glass one, and there are very few that achieve that whitout a barrel of bondo. Because it's so labor intensive in commercial reality it's cheaper to build in metal or fiberglass. Using amateur plasterers usually results in the disaster that killed ferro reputation beginning with the 60's.

    Using the new textile reinforcements has its own problems. You can't just bend the thicker stuff like it's steel, more severe curves have to be preformed by the factory. To achieve the stated thickness most builds use molds, with both hand laminating and spraying beeing used. Pouring complex forms is intensively researched, right now it's the holy grail.
     
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  11. bajansailor
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    bajansailor Marine Surveyor

    A thread about ferro-cement boats was also started a couple of days ago on the YBW Forum in England -
    Concrete boat https://forums.ybw.com/threads/concrete-boat.602029/

    Some years ago a hurricane passed north of us, resulting in 25 - 30 knot winds from the south-west on our west coast, which is usually calm and peaceful with the prevailing NE - SE trade winds.
    Two boats came ashore in Carlisle Bay, on to a gently sloping hard sand beach.
    One was a 37' single chine plywood yacht with a deep fin keel and a spade rudder. I think her rudder broke off, and she sustained one small hole in the hull, but no other (major) damages - she was re-floated and sailed again.
    The other was a 38' ferro-cement yacht - beautifully built in South Africa by a chap who was (is) a master craftsman. However she sustained major cracks in her hull, and they eventually broke her up with a JCB digger, and took the hull away in pieces in a skip / dumpster :(

    Some pals used to live on their 40' ferro cement junk rigged schooner. A jet-ski t-boned them one day and managed to make a hole in the hull where the impact occurred, fortunately above the waterline. I think they were able to heel the boat enough to effect a repair that lasted until their next haul out.
     
    Last edited: Oct 15, 2023
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  12. wet feet
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    wet feet Senior Member

    I don't really follow the logic of building a hull from a cheap material so that you can sail with no prospect of recovering your investment should the worst happen.The cost of a more normal form of hull would also be recouped at sale time as the more conventional boat would have a wider ranging appeal.I can understand why the construction method has pretty much expired as it is very hard work.

    There is also the reality that in some parts of the world there are old salts giving up at a greater rate than people are taking up cruising.Which has led to some well built GRP boats from the 70's and 80's being virtually given away.Sadly,the cost of maintaining and mooring a boat in the 2020's means that a year's boating costs about what the vessel is worth.

    That YBW thread does contain an error in that Windboats Marine ceased trading three years ago and the moulds for the Gunfleet boats were destroyed.I used to know somebody who worked there in the 60's and he related that on plastering days work started at 6 am and nobody went home until the job was done.He was not a great fan of concrete boats.
     
  13. skaraborgcraft
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    skaraborgcraft Senior Member

    Yeah, plastering day is critical, I think the biggest boat i saw done was 45ft, and that was 12 guys working 14 hours. The cement mixer was run non stop for 12 hours.
    These days buying a second hand boat is the cheapest way. People do still build for the experience, and so "re-sale value" or the lack of, is part of getting that experience. I dont know anyone who has built or bought a leisure boat and seen it as an "investment". I certainly would not build in ferro today, given what can be bought instantly on the second hand market; but for the OPs use of a dumb barge type houseboat, it is still valid if not paying someone else to do the work, otherwise steel would be a better choice.
     
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  14. wet feet
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    wet feet Senior Member

    I totally agree that a boat isn't a great way of investing,but it is nice to retrieve some of the expenditure when you sell it on.Few of us would be thrilled to write off all the money we put into a boat but I have heard of people giving up boating whose love of their boat was so great that they would happily give it to a caring owner. Total loss of value makes trading up very difficult.
     

  15. skaraborgcraft
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    skaraborgcraft Senior Member

    Some of the usual misconceptions being told as gospel over there. Some ferro hulls where actually lighter than their wooden counterparts, and needed more ballast, and hence stiffer and better sailers. Admittedly, the majority were not built to excting standards, though Windboats and possibly Potter & Bishop, had Lloyds 100A1 hull certification. The Peter Ibold Endurance range were very comfy cruisers.
     
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