Spraying Gelcoat gun types

Discussion in 'Fiberglass and Composite Boat Building' started by Guest, Jan 19, 2004.

  1. Guest

    Guest Guest

    I have a gravity feed spray gun which I use with spray putty. It has a 2.8 mm fluid nozzle. I was going to try and use it to spray "Gelcoat" but thought I should ask first - will this work. Is there much difference with a spray gun intended for use with gelcoat ???
  2. FibrSupplyDepot
    Joined: Sep 2013
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    Location: Fort Pierce

    FibrSupplyDepot Fiberglass Supply Depot

    That tip size should work fine for spraying gelcoat, just make sure you have acetone ready if it starts getting too hot in your gun, the gelcoat will kick in you gun.
  3. boshores
    Joined: Aug 2016
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    Location: Alford, Florida

    boshores New Member

    Spraying Gelcoat

    I have a G 200 gelcoat gun. It mixes the Gelcoat and the MEKP separately as you spray. I haven't been able to find any information on using this gun. I'm hoping someone can help me that has experience with the G 200. I'm wishing to gain someone's experience so as to make it a little easier for me. I will post my experience to help others. I'm almost at the point of applying the gelcoat. Thanks, James Shores.
  4. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    It's best to start your own thread so people don't get confused about what's being discussed with which person, but...

    There is no way to correctly catalyze the gel coat using an external mix gun of that type, it's just a guess at best, and not even a close one.

  5. redreuben
    Joined: Jan 2009
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    Location: South Lake Western Australia

    redreuben redreuben

    Gelcoat guns

    I've always used pressure pots to spray gelcoat 1 liter or 5, after that your better off with a larger depositor that premixes.

    Gravity guns are good for repairs where the gel is thinned with acetone but too slow and weak for spraying gelcoat.

    Not saying it can't be done just my experience.

    Speaking of depositors, to calibrate you have to isolate the catalyst from the gelcoat, how this might be done on your machine I have no idea, get yourself a manual.
    Spray gel into a container until you have a kilo.
    Then spray catalyst for the same time it took you to get a kilo of gel.
    Now you can calculate the ratio.
    Much easier in metric, maybe you only need 100 grams but keep it simple.
    Do the test at an average ambient temperature like 25C not an extreme.
    I would calibrate for 1.0 and 2.5%.
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