Tooling gel coat wrinkled and blistered

Discussion in 'Fiberglass and Composite Boat Building' started by aaronhl, Oct 30, 2015.

  1. aaronhl
    Joined: Aug 2012
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    Location: Central Connecticut

    aaronhl Senior Member


    I guess I am getting confused because the gel coat is in weight and the mekp is in volume...so are we measuring in volume or weight for consistency?
     
  2. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Grams and CC's are the same, well the weight of resin and catalyst are different than water, so in truth, they aren't exactly the same, but close enough and repeatable, which is the important part.

    The metric system is good that way.
     
  3. aaronhl
    Joined: Aug 2012
    Posts: 209
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    Location: Central Connecticut

    aaronhl Senior Member

    So what if I stick to milliliters both for resin and mekp? I am liking the metric system more and more actually
     
  4. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    That will work well.
     
  5. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    I use metal kitchen scale and cover it with plastic so it doesn't mess up.

    As a guide, 700-900 grams/m2 of gelcoat is a heavy layer
    450- 650 is a medium coat that works best in most application.
    300-400 is a light coat and might cause transparency.

    Find the surface area of the piece you are working on and mix just enough gelcoat to cover the area with your intended thickness. One method is to buy (usually free) this metal/plastic "wet film thickness gauge" from your supplier. You apply the gelcoat and place the gauge vertically against the surface of the mold. Where the gelcoat touches the corresponding notch is your wet film thickness.

    Look also for this plastic squish MEKP dispenser. It is very handy. In the future, look for this gravity fed gelcoat spray gun. Some have disposable quart cups. Very cheap.

    Stick to the unit of measure you are used to. In time, you won't need to weigh or measure. Just use the standard measuring cups that you use.
     

  6. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    Balance beam scales are easy to make and can be very accurate. I made one a long time ago with a stick a few feet long, a nail in the center to pivot on and a string level to show level. I put a combination of pennies and dimes equaling 1 oz hanging in a baggie on one end and a baggie filled with material on the other end, adjusting the material until the level was level.
    Here's a cheap, very accurate home made one...
    http://sci-toys.com/scitoys/scitoys/mathematics/microgram_balance/balance.html
     
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