Reduction of strength due to delamination

Discussion in 'Boat Design' started by Mr. Curious, May 17, 2010.

  1. tunnels

    tunnels Previous Member

    Forgot !!
    I am not a believer in mounting floors and engine beds and any major loadings on top of foam cores i have always mount those types of things onto the solid glass so they are completely bonded with at least 120 mm of glass to where the core starts . Low density foams are a reall problem just because the builder want to save a little money or the designer hasnt done his home work or simply dosent know what the outcome can be . It is absolutely scary to see how easy a sheet of glass will peel off a sheet of foam . :confused:
  2. Mr. Curious
    Joined: May 2010
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Sweden

    Mr. Curious New Member

    I would like to take part of the content in ISO 12215. Do I have to by this or ...

    My intention is to make a test of a piece of laminate by measuring the force needed to pull this laminate apart in Z-direction. Anyone knows what forces that could be expected in a correct laminate i.e. without delamination?
  3. tunnels

    tunnels Previous Member

    The core material you will be using will have had all kinds of tests done anyway so just get there report .
    The one you wont find anywhere is laminate peel off foam because its scary , So when a core is damaged the peel rate is over the moon . and it one very strong reason for a cruising hull to break the panel sizes into small areas that are surrounded by glass to glass . :D
    Its also very interesting to look carefully at the test results and do a comparison between Balsa and all the differant foams on the market . :p
    An interesting subject to do with all cores is called CORE SHEAR !!:confused:

    Dont get me wrong every product has its uses and its place in the scheme of things so its the laminate design engineers job to know and understand what each product will or should be able to do .
    20% or failures are caused by the wrong choice of materials and the other 80% of failures are from Bad workman ship !! :p
    No news travels faster than bad news :eek:
  4. Landlubber
    Joined: Jun 2007
    Posts: 2,640
    Likes: 124, Points: 0, Legacy Rep: 1802
    Location: Brisbane

    Landlubber Senior Member

    Technically the hull can be corrected, economically I doubt it.
    The hull/deck joint will be the problem in doing the topsides, and if not done correctly then the integrity of the boat is totally suspect.

    I doubt that the "entire hull" has delaminated, the below waterline section is solid glass, not cored as are the topsides.
  5. girvin
    Joined: Dec 2009
    Posts: 73
    Likes: 3, Points: 0, Legacy Rep: 37
    Location: Vancouver Island

    girvin Junior Member

    I agree its a gonner I have done a tone of fiberglass repair work. I only fix delams on deck bc I believe after a hull delams the glass loses its strength. even if injected and compressed back it has flexed too much. when I fix delams on surfboards I have to cut all the glass off that has delamed and replace with new overlaping the good glass by 2 inches. I still tell them it might die a early death. IF you go to they just did a test with 13 different core mediums.
  6. girvin
    Joined: Dec 2009
    Posts: 73
    Likes: 3, Points: 0, Legacy Rep: 37
    Location: Vancouver Island

    girvin Junior Member

    landlubber said it. If it can be fixed its not economical.
  7. Tim Judge
    Joined: May 2010
    Posts: 63
    Likes: 2, Points: 0, Legacy Rep: 36
    Location: Hudson River

    Tim Judge Tim J


    Mr. the gel coat blistered and or been repaired where the delamination is found?

  8. powerabout
    Joined: Nov 2007
    Posts: 2,925
    Likes: 66, Points: 48, Legacy Rep: 719
    Location: Melbourne/Singapore/Italy

    powerabout Senior Member

    I sailed on a 75' yacht built in the worst yard in Taiwan and in the middle of its layup someone used waxed glass...oops!
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.