Oxidised metal plate in polyester hull has oxidised and expanded. Repair needed. Help

Discussion in 'Boatbuilding' started by John Horton, Jul 12, 2020.

  1. John Horton
    Joined: Jul 2020
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    Location: Granville,france

    John Horton Junior Member

    Hello,my firs post.thanks in advance guys.
    I have bought an Etap 26, Twin skin,foam filled sailboat. Designed and produced 1981 -1988.
    As you can see the steel plate that is glassed in the outer skin has oxidised and expanded,a design error in early boats. The plate supports the starboard rigging, so I need to replace it, either with a steel or galvanised anyonplate. Has anyone some words of wisdom of how to do this by way of a protocol to follow.
    The area on the hull is about 6 inches square.
     

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  2. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    Welcome to the Forum John.
    If you have posted a photo, it is not visible - maybe because this is your first post.

    For other readers here is some background info on the Etap 26.
    https://sailboatdata.com/sailboat/etap-26

    Hopefully your photo will be posted soon - as the saying goes "a photo is worth a thousand words" of explanation.
     
  3. bajansailor
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    bajansailor Marine Surveyor

    Your photos have now arrived finally, excellent!

    That plate looks very strange - I guess it is rusting, and pushing up the laminate above it?
    Do you have any photos showing this part of the hull on the interior?
    It appears to be in way of the chart table (re the GA drawing in the sailboatdata link) - is there a tie rod going from the plate in the hull up to the deck?
     
  4. John Horton
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    Location: Granville,france

    John Horton Junior Member

    Hello bajansailor, thank you for you reply. yrs, a tie rod extends between the two skins from the plate at about 20 degrees from vertical to the deck where the secures the starboard shroud
     
  5. bajansailor
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    bajansailor Marine Surveyor

    Thanks for this - if you could post a photo or two showing the arrangement on the inside then that would be useful.
     
  6. John Horton
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    John Horton Junior Member

    Will get photos on Wednesday as over here it's a holiday, so the boatyard is closed, so no key. I sign for ownership wednesday. I am very confused about how to remove and replace the plate, and how to ensure a strong bond to say stainless steel and maintain the integrity strength of the hull.
     
  7. bajansailor
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    bajansailor Marine Surveyor

    Is there also a glassed in plate on the port side as well? If there is, is it displaying any signs at all like the one on the starboard side?
    The plate must have a fitting welded on to it on the inside, to which the tie road is attached?

    Re how you are signing for ownership on Wednesday, have you agreed on a price for the boat, without taking into consideration that this could be a fairly major repair job? Or have you already negotiated a good discount on the asking price because of this possibly complicated repair?
     
  8. Rumars
    Joined: Mar 2013
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    Location: Germany

    Rumars Senior Member

    It's a known problem. You need to cut a hole (approx. 50x60cm) in the inner liner (I think the location coresponds to backrests on your model), grind away the laminate over the plates, then remove them. Fabricate new stainless plates (used to be available from the factory as a kit) glue in place and laminate over them with fiberglass and epoxy. Close the holes you made, then the last step is to repair the hairline fractures on deck around the tierod exits wich allowed water in.
    The rig needs to come down for this repair, and I urge you to not sail the boat before you do it since you risk a dismasting (you would not be the first boat).
     
  9. John Horton
    Joined: Jul 2020
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    Location: Granville,france

    John Horton Junior Member

    Hello Rumars, thanks for your reply. Would the outer hull then reform to its original level when the plate is removed? or, the bump flatten on the external hull?
     
  10. Rumars
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    Rumars Senior Member

    In theory yes, it will flatten back, but there are no guarantees. If it does not you have a problem but I doubt you want to do the proper repair.
     
  11. John Horton
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    John Horton Junior Member

    Hi Rumars,well I am happy to spend 1.5k if it will cover the job,what do you think there possible cost could be?
     
  12. Rumars
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    Rumars Senior Member

    I have no way to estimate what the repair will cost.

    If the bulge does not go back the fiberglass is permanently damaged and there are two solutions. You massage the bulge back as best as you can and laminate over the whole area on the inside reinforcing it before you stick the new chainplates on. A skilled person can even grind some of the inside glass away without damaging the gelcoat to get a better result. But it will probably always show.
    The proper repair is to cut the bulge out and relaminate the area completely. Not complicated or even expensive until it comes to the esthetic part. Matching the gelcoat so the repair is invisible is a tall order by itself, and with the rest of the gelcoat beeing so old it's likely that it will show colour differences down the road. A sure way to long lasting results is to repaint the entire topsides but that is expensive.
    It all comes down to what you can stomach in the way of how your boat looks.

    One last thing, if you want you could replace the stainless plates with composite chainplates.
     
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  13. John Horton
    Joined: Jul 2020
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    Location: Granville,france

    John Horton Junior Member

    I have to say a big thank you Rumars,for a concise and helpful reply.I will probably go for the latter,as I won't be satisfied with a poor job.It will be a labour of love and hope to sail her next season.thanks again for your help.
     
    Will Gilmore likes this.

  14. kapnD
    Joined: Jan 2003
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    Location: hawaii, usa

    kapnD Senior Member

    I’d look into removing the plate and then reinforcing the actual hullsides with frp buildup, and fabricating a bracket.
     
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