fiberglass overlay on wooden structures

Discussion in 'Materials' started by urisvan, Mar 20, 2008.

  1. urisvan
    Joined: Nov 2005
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    urisvan Senior Member

    i saw some wooden boats that are coated with fiberglass.
    do you thinh is it healty?
  2. TeddyDiver
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    TeddyDiver Gollywobbler

  3. Petros
    Joined: Oct 2007
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    Petros Senior Member

    It works and is usually faster than recaulking all the seams and refinishing the hull (but more costly). If the hull is not designed for fiberglass (as they are in stitch and glue or strip built), than all you do is add weight, and risk trapping moisture between the fiberglass and the wood, speeding up decay. It is usually more costly to do this than a proper repair (unless the hull is already badly rotting and leaking-in which case you only put off the inevitable). It also makes major repairs/rebuild/restoration more trouble later.

    I do not think I would do this on classic wood boat, and only consider it on a junky knock -around play boat.
  4. Ike
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    Ike Senior Member

    Some like it, some don't. I'm one of the don'ts. Others here will say it is a good technique. Oddly enough I am currently building a stitch and glue boat that does just that. I'll see how it works out.

    Basically though, IMO if you have a wood boat that is on it's last legs and not worth the cost of rebuilding in wood, fiberglass may extend it's life a few more years.

    If the boat is in relatively good condition and just needs replanking you would be better off not glassing it.
  5. urisvan
    Joined: Nov 2005
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    urisvan Senior Member

    thanks everybody,
    is it still like that, even if you overlay fiber only on the outside of the hull?

  6. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    The basic problem with 'glass sheathings on existing structures is the wood will continue to vary it's moisture content, because it's not completely encapsulated in plastic. This coupled with the fact that many traditionally built structures (carvel, lapstrake, etc.), have a substantial amount of movement among the elements, which pretty much guarantees the hard, reinforced plastic skin, will sheer from the substrate.

    The only true way to 'glass a traditional wooden hull is to provide sufficient sheath thickness to make basically a second hull, which surrounds the wooden one. The 'glass skin then is quite heavy and can absorb the loads imposed under way and by it's equipment or crew. The wooden structure then lives in a plastic shell, which can prolong the life of an otherwise tied hull. This is a common practice when a workboat reaches the end of it's useful life span and a few more years of service is desired, before a new boat replaces it.

    This said, other construction types tolerate 'glass sheathings quite well, in fact some can't exist without them or at least 'glass taped seams. In the end, many honest answers to difficult questions must be addressed, before a decision can be made in this regard. Some of those questions would include: will this particular construction type accept a sheathing readily, will conventional repair costs out weigh a 'glass job, what are the long term goals for the vessel, future repairs issues with and without the 'glass skin, resale value, etc. Only the owner, in concert with a skilled builder or designer can access the pros and cons for a specific vessel. Each will require individual analyses on a one by one level.
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