Painting with brush with Tru-Color flat paints

rogergperkins May 29, 2015

  1. rogergperkins

    rogergperkins TrainBoard Member

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    I have been doing some kit modifying, scratch building and laser wood kit assembly recently.
    I am using the Tru-Color Paints, the flat finish version on a modified DPM kit.
    The first coat on all the walls was brick red; it went on very nicely and with two coats gave very good coverage.
    I then decided to paint some of the trim with "earth".
    I found that with the micro brush application that the brick red was starting to be lifted, so I stopped.
    How long do these paints need between coats if an different color is used in the 3rd or trim coat?
    I do not recall experiencing this issue in many years with Polly S.
     
  2. John Moore

    John Moore TrainBoard Supporter

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    I have had the same issues over the years with a number of paints, even solvent based paints like Floquil and before that with the old Scalecoat. A couple of the factors that influence drying time are the thickness of the initial coat, the temperature, most all drying time estimates are based on having 70 Deg. F or above, and the humidity level. I have had some stuff still be tacky at 48 hours when the published drying time was 24 hours. I have had Poly S set up well enough to take a 2nd coat in less than 6 hours, but that has been because I sat the object on a small fan directed straight up and had optimum temperature and humidity level.

    From your description I would speculate that the first coat was not completely cured before the 2nd coat was applied. And in that case I would give at least twice to three times the amount of cure time as specified for the paint.
     
  3. BoxcabE50

    BoxcabE50 HOn30 & N Scales Staff Member TrainBoard Supporter

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    Is it the base coat lifting off the kit material? Did the kit receive any cleaning before starting to paint?
     
  4. Doug Gosha

    Doug Gosha TrainBoard Member

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    Solvent/lacquer-based paints can always have this issue, even after completely cured, because a new, wet coat of paint can still dissolve the previous coat. Oil-based enamel paint won't have the problem if is completely cured because a new, wet coat will not dissolve the previous coat.

    Water-based paints shouldn't have the problem if the first coat is completely cured for the same reasons as oil-based paint. The issues are, when is it completely cured and what is the exact paint formulation?

    I have never had this happen with Poly Scale (a water-based paint) either, even just waiting a half hour or so.

    Doug
     
  5. umtrr-author

    umtrr-author TrainBoard Member

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    I find that if I'm not careful, I will lift off a first coat of water-based paint with the second. Usually, the root cause is my own impatience.
     
  6. rogergperkins

    rogergperkins TrainBoard Member

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    Thanks for the replies.
    I did NOT wash the DPM kit parts with soap and water before I began painting.
    The first two coats for brick red went on fine and were done about 24 hours apart. The second coat did not raise the first coat at all.
    I waited another 24 hours or so before I started painting trim.

    Personally, I would not have formulated these with acetone as a solvent. Solvent like that in Polly S would have probably eliminated this issue.
    So, looks as if I need to be more patient before I paint the trim.
     
  7. Doug Gosha

    Doug Gosha TrainBoard Member

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    I have a Crestone Credit Union that went about 18 years between the base color and window/trim painting and it isn't because I was waiting for the base color to dry. I actually painted one window and part of the front trim, back then, and decided I didn't like doing it. This aspect of DPM models (having to paint the windows in place) has kept me from buying any more of them over the years.

    Needless to say, when I finally finished it, recently, there was no paint bleeding or lifting. :funny:

    Doug
     
  8. rogergperkins

    rogergperkins TrainBoard Member

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    Doug, I have essentially done the same with many of the DPM kits. I am eager to see the structure and assemble and paint the walls, then put the structure on the layout and some years later decide to paint the windows and trim. This was in the day when Polly S paint was available. My current situation is I have NO LAYOUT to put them on; assembling kits is the only modeling I am doing.
     
  9. John Moore

    John Moore TrainBoard Supporter

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    One of the things that I have been doing for some time now is to paint all the trim first including windows and doors. I have found it to be a lot easier then to use a very fine point brush to apply the base color carefully up to the trim and then use a larger brush to finish out the structure. Life has been just a little easier since I started that. Of course I have been spoiled by a lot of the decent kits with separately applied windows, doors, and trim that can be painted as separate pieces and have come to prefer them to stuff with one piece casting.
     
  10. rogergperkins

    rogergperkins TrainBoard Member

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    The reason I did not do the trim and windows first is because I never know exactly what color I want to use until I have the base walls painted.
    I suspect of the many DPM kits I have assembled, I have never decided on a color until I have the four walls assembled and a roof flat cut to size.

    I have lot track of how many of the DPM kits I have. Just purchase 4 more recently with the idea of modifying them during assembly. The first of these is Hayes Hardware #50200 which I used only the front and back walls and used a brick sheet for the side walls and made it 60 scale feet deep. I just used the Hayes Hardware side wall with the Roadkill Café #51200 kit front and back walls which increased the depth from 2.75 inches to 3.25 inches. I used my new Rite-way magnetic clamps to fix the walls at a 90 degree angle until the glue set. I was eager to try the clamps, more than to assemble another kit.
     
  11. rogergperkins

    rogergperkins TrainBoard Member

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    My impression is that I going to shop for alternative flat acrylic hobby paints for the structures I am currently assembling.
    I think the acetone is a part of the problem I am experiencing with coverage.
     
  12. Fishplate

    Fishplate TrainBoard Supporter

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    I had the same issue with Tru-Color when trying to touch up a multi-color paint job. This stuff is great for airbrushing, but when brushed on it tends to dissolve the color underneath, even after generous drying time. Maybe a coat of clear acrylic over the first color would seal it and prevent this. Has anybody tried that?
     
  13. BoxcabE50

    BoxcabE50 HOn30 & N Scales Staff Member TrainBoard Supporter

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    An interesting idea. Hopefully the clear coat is not also water soluble?
     

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