Glossy spots on parts after dip and rinse? — K2Forums.com

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Glossy spots on parts after dip and rinse?

Ryactive_RyanRyactive_Ryan Posts: 24Member
edited February 20 in Water Based Paints
Hey all, I've recently started using Aqualac 35 paint, and a lot (most) of my test pieces are coming out with glossy spots on them, and some even have a textured feel to them. I have attached a pic as examples. And here are the details of my dipping environment:

Paint used: Aqualac 35 (multiple colors)
Paint gun: Vaper HVLP w/1.4mm tip
Tank Temp: 30C. (86F) - got same result in a cold (59F) dip.
Rinse temp: 45C (113F) - same result in cold rinse.
Film soak time: 60-80 seconds
Time to dip after activation: 10-15 seconds
Rinse time: between 3 and 7 minutes (also tried up to 15 minutes with same result
Room temperature: about 23C (73F) w/ close to 0% humidity (not sure if this even matters?)
Pic was taken after piece was thoroughly dry.

I hope this question isn't too vague or unclear... just kind of stumped.

Thanks.


Comments

  • MidOhioHydrographicsMidOhioHydrographics Posts: 8,516Member, Moderator, Business Ninja El Moderator
    edited February 20
    I think you need to rinse more. Sure looks like it is just residual PVA.
  • MidOhioHydrographicsMidOhioHydrographics Posts: 8,516Member, Moderator, Business Ninja El Moderator
    And your rinse temp should be just below the temp of your tank. I wouldn't exceed 85F if you're heating. It will help w/ heated water tho.
  • Ryactive_RyanRyactive_Ryan Posts: 24Member

    I think you need to rinse more. Sure looks like it is just residual PVA.

    That was my first thought, which is why I decided to rinse the piece in the pic for about 15 minutes thinking it should do the trick. I currently have a piece that has been in the rinse station for the last 30 minutes, and it still has these same spots. Even more stumped now. I'll leave it in there for awhile longer to see if there are any changes.
  • Ryactive_RyanRyactive_Ryan Posts: 24Member
    And just to clarify, I am only having this issue with the Aqualac 35 painted parts... I have not had this issue with other paints... which got me wondering if it had something to do with the paint.
  • MidOhioHydrographicsMidOhioHydrographics Posts: 8,516Member, Moderator, Business Ninja El Moderator
    edited February 20
    I use Aqualac every single day. I order it in drums and we spray from a pressure pot that holds a 5-gallon bucket. Thousands of parts per week. Never had this issue, but that doesn't mean it's not something in that particular batch. But you said it was multiple colors, correct? Try lightly rubbing the spots and see if they feel slimy. You can normally get away with light rubbing on Aqualac. Or spray w/ a hose nozzle and fan pattern. We spray our freshly dipped parts quite often w/ a water jet (pretty darn hard) w/ no issues. Especially when dipping desert digital. Sometimes our rinser leaves little dark brown lines of film that stick out like a sore thumb if we don't.
  • MidOhioHydrographicsMidOhioHydrographics Posts: 8,516Member, Moderator, Business Ninja El Moderator
    And well done on formatting your question. Great info provided about the entire process and a picture. I wish everyone would do this! LOL
  • Ryactive_RyanRyactive_Ryan Posts: 24Member
    @MidOhioHydrographics I tried the lightly rubbing suggestion... it does not feel slimy at all, but the rubbing did dull the glossy spots, almost making them disappear, yet there is still evidence that the spot was there. Thanks for the info on your use of this paint... I will try your rinse suggestions. I suspect I may not have either enough volume, or enough pressure in the rinse station, or a combination of the two.
  • Ryactive_RyanRyactive_Ryan Posts: 24Member

    And well done on formatting your question. Great info provided about the entire process and a picture. I wish everyone would do this! LOL

    Thanks... as I'm new to this whole forums thing, thanks for confirming that I took the right approach (I wasn't sure). I figured like anything else in life, if you want an answer to a question, you need to provide the information you already have.
  • MidOhioHydrographicsMidOhioHydrographics Posts: 8,516Member, Moderator, Business Ninja El Moderator

    @MidOhioHydrographics I tried the lightly rubbing suggestion... it does not feel slimy at all, but the rubbing did dull the glossy spots, almost making them disappear, yet there is still evidence that the spot was there. Thanks for the info on your use of this paint... I will try your rinse suggestions. I suspect I may not have either enough volume, or enough pressure in the rinse station, or a combination of the two.

    That's possible. Let me know what happens w more rinsing. Strange. I'm still sticking w PVA. Just no idea what else it could be.
  • smedlinsmedlin Posts: 1,061Member, Business Ninja ✭✭✭✭
    Out of curiosity, would his water temps have anything to do with it?


    Tank Temp: 30C. (86F) - got same result in a cold (59F) dip.
    Rinse temp: 45C (113F) - same result in cold rinse.

    I've always read rinse temp needs to be less than dip temp.
  • WileECoyoteWileECoyote Posts: 5,488Member, Moderator, Business Ninja El Moderator
    That was one of the first things he mentioned @smedlin
  • WileECoyoteWileECoyote Posts: 5,488Member, Moderator, Business Ninja El Moderator

    And your rinse temp should be just below the temp of your tank. I wouldn't exceed 85F if you're heating. It will help w/ heated water tho.

  • Ryactive_RyanRyactive_Ryan Posts: 24Member
    edited February 20
    smedlin said:

    Out of curiosity, would his water temps have anything to do with it?


    Tank Temp: 30C. (86F) - got same result in a cold (59F) dip.
    Rinse temp: 45C (113F) - same result in cold rinse.

    I've always read rinse temp needs to be less than dip temp.
    I've read both higher and lower than dip temp... have tried both and got the same result. Thinking it may be more related to length of rinse time and flow of water. My station has a decent flow rate, but very little pressure. Wondering if that is the culprit.
  • smedlinsmedlin Posts: 1,061Member, Business Ninja ✭✭✭✭
    Dop, you did say that Mid.

    (I devour everything y'all say, to learn..)
  • WileECoyoteWileECoyote Posts: 5,488Member, Moderator, Business Ninja El Moderator
    @Ryactive_Ryan I have never seen that with Aqualac before, and have never seen PVA hold up to more than 15 minutes of even the WEAKEST water streams, and much less... light scrubbing with your fingers
  • NotSoFastNotSoFast Posts: 3,059Member, Moderator El Moderator
    Do other films over Aqualac do this too, or just this film?
  • Ryactive_RyanRyactive_Ryan Posts: 24Member
    NotSoFast said:

    Do other films over Aqualac do this too, or just this film?

    I have had it happen now with 7 different films.

    **UPDATE** I did 3 different colors on a total of 10 speed shapes, covered each in a different film, and all 10 have experienced the same result as pictured above. On a positive note, once cleared, the spots are not noticeable, however, on a very negative note, there is a slight texture to the pieces that I cleared.

    Did I mention I'm stumped?
  • MidOhioHydrographicsMidOhioHydrographics Posts: 8,516Member, Moderator, Business Ninja El Moderator
    Ok, right after you dip, take one of the speed shapes to the sink and run warm water over it while rubbing. See if you can get all of it off.
  • DeviousDipsDeviousDips Posts: 1,014Member ✭✭✭✭
    What about taking tank temp to 90 or 91. Seems like it's not fully hydrated. 
  • K2ConceptsK2Concepts Posts: 12,198Administrator El Jefe
    You are underactivating the film...Aqualac will "knuckle up" the paint when you underactivate...ask me how I know...it will also "buckle" the paint when you don't let it dry thoroughly...Aqualac is a GREAT paint but it can't make up for our bad technique...we use it every day and still we learn a thing or 3 when the weather changes...
  • Ryactive_RyanRyactive_Ryan Posts: 24Member
    @K2Concepts thanks for the insight! I'll pay special attention to these areas on my next run. I will admit, I think I may under activate more often than I'd like out of fear of over activating. I guess I still have to find that happy medium with each film. As for paint drying... I'm guilty. And I didn't realize it until you mentioned it, but I suspect that may part of my problem... most of these parts were dipped within an hour of painting, which I'm assuming is too soon?
  • MidOhioHydrographicsMidOhioHydrographics Posts: 8,516Member, Moderator, Business Ninja El Moderator

    @K2Concepts thanks for the insight! I'll pay special attention to these areas on my next run. I will admit, I think I may under activate more often than I'd like out of fear of over activating. I guess I still have to find that happy medium with each film. As for paint drying... I'm guilty. And I didn't realize it until you mentioned it, but I suspect that may part of my problem... most of these parts were dipped within an hour of painting, which I'm assuming is too soon?

    Nah. 1 hour should be more than enough time
  • WileECoyoteWileECoyote Posts: 5,488Member, Moderator, Business Ninja El Moderator
    Especially if you are using Aqualac... It's HARD to overactivate.
  • WileECoyoteWileECoyote Posts: 5,488Member, Moderator, Business Ninja El Moderator

    I will admit, I think I may under activate more often than I'd like out of fear of over activating. I guess I still have to find that happy medium with each film.

    This is not exclusive to you @Ryactive_Ryan but in an attempt to prevent a problem you haven't experienced, you have inadvertently caused yourself a different problem, when in actuality neither should be if you follow the process. This is not to pick on you personally, just trying to summarize the issue for the class.

    As for paint drying... I'm guilty. And I didn't realize it until you mentioned it, but I suspect that may part of my problem... most of these parts were dipped within an hour of painting, which I'm assuming is too soon?

    The hour of dry time depends on alot of things... Temp, humidity, and airflow. Take your parts and put them in front of some low heat (no more then 100° F and they will be dry within 20 minutes.
  • K2ConceptsK2Concepts Posts: 12,198Administrator El Jefe
    Yea I was going to suggest sticking the parts in your office or in front of an IR lamp...MUSH better success than air drying this time of year...or at least that's what we are finding out...
  • BEMOTORSPORTSBEMOTORSPORTS Posts: 170Member ✭✭
    edited July 9
    @ryactive_ryan thanks for this thread i have had simular issues and thanks to this thread i have narrowed it down to under activating thank you everyone 
    Post edited by WileECoyote on
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