Cleaning Gelcoat from HVLP spray gun

Discussion in 'Materials' started by BrettinVA, Apr 12, 2019.

  1. BrettinVA
    Joined: Nov 2016
    Posts: 32
    Likes: 0, Points: 6, Legacy Rep: 7
    Location: Suffolk VA

    BrettinVA Junior Member

    Howdy gang!! I got adventurous last week and bought a 2.5 gelcoat HVLP gun, one that's made for solvent cleaning etc. It sprayed good even without thinning the gelcoat and I was able to manage my spray time but it's a pain in the you know what to clean the gun after. Even with 5 minutes before my 15 minute timer started the gel was really thick in the chamber behind the tip and after spraying a cup of acetone a lot was still inside the gun. By my 3rd cleaning I was using a half gallon pail of acetone to dunk most of the gun after I pulled the needle and nozzles. Does anyone have a better process? Can you run acetone though an auto parts cleaner? Thanks in advance!
     
  2. Blueknarr
    Joined: Aug 2017
    Posts: 617
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    Location: Colorado

    Blueknarr Senior Member

    Welcome to the gelcoat spray club.

    I clean by first flushing with used acetone. Then I completely break down the gun. All parts go into a 6x9 baking pan 1/2 full of acetone. I scrub everything with soft bristles or wooden bbq skewers or toothpicks, never metal brushes. Change to clean acetone and wipe down. Reassemble gun and one final flush with acetone. I keep acetone in thred containers (virgin, used and near mud)

    Some parts cleaners can use acetone others no. It is a hose/gasket comparability and spark/fire issue.
     
  3. BrettinVA
    Joined: Nov 2016
    Posts: 32
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    Location: Suffolk VA

    BrettinVA Junior Member

    Thank you for the reply. That's pretty much how it ended up for me but I used a dental pick set to pull the chunks out. LOL. I used a kitchen style filter screen to get the gel chunks out of the acetone between uses. Seems a lot more gun guys use acetone in parts cleaners than anyone else - go figure. I may try it. There are parts cleaners on FB marketplace for 50-100
     
  4. Blueknarr
    Joined: Aug 2017
    Posts: 617
    Likes: 92, Points: 28
    Location: Colorado

    Blueknarr Senior Member

    Beware the issues I just previously mentioned about spark hazards and acetone.

    I'm wary of scratches from metal scrapers.

    Remember gelcoat will cook off faster in confined pots than spread out on a surface. The metal frame of the gun will increase heat gain and speed things along.
     
  5. Sparky568
    Joined: Jan 2017
    Posts: 84
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    Location: Northeast USA

    Sparky568 Junior Member

    Spraying gelcoat is definitely a PITA. There are no two ways about it. Cleaning up is literally half the work. If you are doing a lot of it get multiple cups or disposables. I am by no means an expert at this but, what I have found is spraying 250ml at a time works for me. For my 2.5 gun I use three spare cups. I use one strictly for spraying acetone through the gun between mixes and get help cleaning the cups used for gelcoat and mixing the next batch. Still, you need to completely disassemble and clean the gun after two maybe three batches at most.
     

  6. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Or, switch to a 3M spray gun, no clean up is required. All the plastic parts are cheap, the disposable parts cost less than the acetone required to clean them.
     
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