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Geopolymer Boat Construction

Home Forums Community Dreaming / Crazy Ideas / Speculation Geopolymer Boat Construction

This topic contains 4 replies, has 4 voices, and was last updated by Profile photo of david fitzgerald david fitzgerald 1 year, 3 months ago.

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    Profile photo of Jolly Roger
    Jolly Roger

    Hello all,

    I thought this idea would be right up your alley. I am researching materials & techniques to construct a geopolymer based boat. Thus far I have found some more modernized composite materials which address many of the problems of ferrocement construction, mainly corrosion of the steel armature and the potential for cracking of the plastered surface.

    I am curious if anyone has done research on the subject and could possibly share some knowledge of techniques for working with these composite materials for marine applications. I have read the FOA pdfs produced by the US navy for constructing ferrocement boats from the 70s and theoretically these concepts would work with newer materials but it doesnt hurt to see if there are more modern methods people have already explored.

    Some links from my research:

    US navy documents from 70s:

    California Concrete Canoe competition:


    Basalt mesh/fibers for armature:

    Photos of a recent ferrocement boat construction:

    Thanks for reading and please keep comments constructive!

    Profile photo of

    Good stuff, Roger, thanks. I’d heard of manmade rock fibers (as in: not asbestos) used in various ways, but the energy input to make them seemed awefully high, is the situation different now? I had also heard of a liquid one could pour on sand that partially dissolved it, decades ago, before the internet, and when it “dried” could be used like a hard sandstone, and i had forgotten about it. I had heard someone had gone so far as set up a corporation to cast bricks from lava right at the volcano, but i have not heard of it in many years.

    Profile photo of

    You gave the url
    which gives the url
    which is 404. The correct url is:
    This all reminds me of a silica solution i used once to repair a cracked windshield. Silica has a close index of refraction as glass, and the crack became invisible when the liquid set up.

    Profile photo of OCEANOPOLIS

    While I am not familiar with any marine application of geopolymers, as a rule of thumb, any new technology that might need further research tends to be expensive. I would stay away from “reinventing the wheel” when it comes to seasteading. But that’s just me.

    There are no problems with ferrocement, if done right. There where just few bad apples plus a conspiratory effort at the time to bash ferrocement in order to promote fiberglass as a first choice for a boat building material. In general, any material, product or technology that is “too good” will be trashed by the competition in order for them to sell their shity stuff. Just look at marijuana :)

    Also, keep in mind that in general, ferrocement is used for floating structures up to around 100′-150′. Larger floating seasteading structures should be built of steel rebar reinforced concrete and there seems to be no problem whatsoever with that method of construction.


    The geopolymer has zero permeability , so the chloride ions from seawater will not penetrate the mortar and will not corrode the steel reinforcement. There are now several commercial geopolymeer mortars available, but I think it is yet more caustic than portland cement so you will need be wear protective gloves etc to avoid caustic burns. You can also add non-metallic fibers to furhter improve its resistance to fatigue cracks etc.

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