Bubbles in fiberglass lamination

Discussion in 'Boatbuilding' started by mariobrothers88, Nov 7, 2021.

  1. mariobrothers88
    Joined: Sep 2020
    Posts: 164
    Likes: 7, Points: 18
    Location: San Diego, CA

    mariobrothers88 Senior Member

    Hi guys, on the first hull of the catamaran I was building I didn't have a bubble busting roller. When I laid the 17oz biaxial fiberglass over the chine joints, I wasn't very careful about examining for bubbles after finishing the job. I felt like I did a good job of laying down the fiberglass that there shouldn't be any bubbles but now I'm paranoid that there might have been some air bubbles I missed in the biaxial fiberglass. I was a lot more careful when I did the second hull. How big of a risk is it if I missed some small air bubbles? When I put the boat in the water could it cost serious delamination or other issues? What can I do now to check? I've already painted it with bottom coat so I can't do a visual inspection. I was thinking of getting an ultrasound machine to look for air bubbles but that would be pretty expensive. Does anyone have any other suggestions?

    Thanks for all the help and advice on this forum I really appreciate it.
     
  2. Blueknarr
    Joined: Aug 2017
    Posts: 1,232
    Likes: 290, Points: 83
    Location: Colorado

    Blueknarr Senior Member

    No use crying over spit milk.

    Bubble problems are directly related to size and number.

    I'm sure you would have noticed any large enough to cause delamination.

    Small bubbles can have a zipper effect once delamination starts but won't cause delamination on their own.

    Hopefully you used wide tape overlaps. The larger surface area of the joint will mitigate adhesion losses.

    I would carry on. As the other options are rather expensive.

    An add on

    Bubbles will also supply a place for osmosis to collect and then expand. Again the potential problems are size related. Sufficient barrier coating should prevent all osmotic problems.
     
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  3. bajansailor
    Joined: Oct 2007
    Posts: 2,382
    Likes: 813, Points: 113, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    What type of roller were you using?
    I am sure that you were taking care (even subconsciously) to avoid bubbles as you laid down your fibreglass - anything obvious would have stood out and you would have had a go at it with the roller that you have until you had flattened it fairly well.
    If there are any air bubbles they are going to be pretty small if you didn't notice them when you were rolling originally.
    If the chine joints have the recommended laminate schedule applied, and they look and feel reasonably smooth, then I wouldn't worry about it now.
     

  4. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Not much you can do. Tap test it if u want. Take a small screwdriver and hit the hull with the hard plastic end where you think you may have voids. If you have any really obvious noise differences, the voids sound kind of rattly. Kind of hard to fix now. You would be able to inject them if they were dime sized or bigger.
     
    bajansailor likes this.
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