Home Forums Explore Media Airbrush Help with painting Polystyrene

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  • #985620
    GlenTaylor
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        Hi all

        I need to know what paint I could use to paint onto polystyrene, as an undercoat or primer so that I could eventually paint two part clear coat over this to make this fuel proof. The fuel is the type that is used with RC aircraft.

        I was thinking a water base acrylic, to seal the polystyrene, then the 2K enamel.

        Glen

        #1068338
        slaterza
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            Sorry Glen you have ventured into unknown territory for me so you will need to have some other helpers jump in with their knowledge.

            #1068363
            MTspacez
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                I’m not sure what the new tech has come up with, but in the olden daze, solvent based paints would dissolve the polystyrene like those foam Christmas balls. If you can get hold of the material you’ll be using for a low cost, you may want to try sealing it with a waterbased polyurethane and then painting over that. I know that AutoAir won’t ruin the foam, but I’m not sure how fuel proof it will make it. You’ll probably have to play “Mr Science” and do some xperimentin’ on your own.

                MT

                #1068344
                bod2306
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                    Glen,
                    You might try an adhesion promoter, like the type they put on auto bumpers. I think that the plastic bumpers are a form of styrene.

                    Brent

                    #1068348
                    airbrush_ken
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                        I’ve done a fair amount of work with the sign industry Glen and from my experience…you can’t put any solvent based paints on the foam… Water borne urethanes will stick well to the surface and you could try two or three coats of the clear medium…which is super gloss… then do a test with the fuel..
                        I don’t know if you can clear the foam with solvent based clear after all the water borne urethanes…again do a test on a small piece.. I know the Solvent based paints will stick well to the waterborne paints..

                        I’d like to know what happends…you may become a hero of the masses if you can work this out…

                        Ken

                        #1068350
                        GlenTaylor
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                            Thanks all for the helpfull hints.
                            I have to become the hero of the masses Uncle Ken as this means I will be painting lot of wings for the glides we fly at work. LOL

                            Glen

                            #1068362
                            Hidiho
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                                I know that AutoAir won’t ruin the foam, but I’m not sure how fuel proof it will make it.
                                MT

                                According to the Auto Air website the auto air paint is durable enough to handle 109 octane race fuel on an uncleared surface..

                                There is a link in the techical page http://www.autoaircolors.com/technical.htm that goes to a slide show of durabilty of the Auto Air Paint and this is where my information was gathered..

                                Hidiho

                                #1068351
                                GlenTaylor
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                                    Thanks, we cant get autoair color in South Africa, and to get it in for a test is just going to take to long, I will try our paint supplies to see what they recommend.

                                    Glen

                                    #1068341
                                    Penny220
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                                        Make a fiberglass shell around it? They should sell Lexan paint where you buy RC cars and such. This paint is made for the flexible plastic bodies and isn’t damaged by the fuel they use, you might want to check into it.

                                        “A life is not important except in the impact it has on other lives.” Jackie Robinson "No one said it had to be real, but it's got to be something you can reach out and feel" Meatloaf
                                        #1068349
                                        airbrush_ken
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                                            Hidiho is right…most waterborne urethanes are un effected by most fuels after they have cured (72hours) but they do react to some paint solvents and prepsol…
                                            Doc Martin also makes a waterborne urethane…not sure of the name…that has been on the market way longer than AutoSnot..lol… See if that might be near you…
                                            If push comes to shove..PM me and I’ll send you a sample of the stuff I designed many years ago for you to try…we sell gallons to the movie industry here and in NZ..

                                            Ken

                                            #1068352
                                            GlenTaylor
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                                                Thank All.

                                                Penny I think the fibreglass, may make the glider to heavy, I will test to see how much wait it will add to the glider.

                                                I think I must tell you all what, where, why.

                                                This is a Polystyrene glider that will fly home from +-240Km, this is for the weather people, they send the weather measuring equipement with the ballon in the glider. At 40000 feet it is released and drops the earth hopefully landing at home. This means the equipemnt is not lost and can be reused, the equipement is expensive as on would imagin. The size is =-1m wing span, wieght is important because we need battery power to fly home.

                                                We are running test and this is working well this far, this is one of the reasons I have not been painting as nust as I would like to, but that life.

                                                I will try to get the waterborne urethane, may not be Dr Martins be should be the same. I will call on you Uncle Ken if I run out of option here, thank for the offer.

                                                Glen

                                                #1068342
                                                Penny220
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                                                    There’s something they put on top of foam that gives it a hard shell. It’s a very thin layer and resembles that of a candy coating on M&M’s. A liquid resin of some kind? I would check with an RC store and a train store to see what it is they use. I’d also search of WC for paper mache (sp) they may know what the stuff is too. It’s not plaster though, it’s more of a plastic coating.

                                                    “A life is not important except in the impact it has on other lives.” Jackie Robinson "No one said it had to be real, but it's got to be something you can reach out and feel" Meatloaf
                                                    #1068353
                                                    GlenTaylor
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                                                        Hi Penny

                                                        I think the product that you think of is the Vanillacryl, I found this on the net, it foams a hard coat on the polystyrene. I must still find the manufacture (Special Effects Supply Corp)
                                                        http://www.fxsupply.com/materials/foamcoat.html

                                                        (The Site has some very nice things for the body artist)

                                                        and the the SA agent. Importing paint in is not the easiet to do. I did find a waterbased primer, that is used on PCV, this is a multi purpose, well we know they say that but not always true. I painted one of the wings with the primer and will test it tomorrow for adhesion. I will let you all know what happens.

                                                        Thank all

                                                        Glen

                                                        #1068354
                                                        GlenTaylor
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                                                            Hi All

                                                            I have done the test and this is what I found. The waterbase primer provided a flexible tuff covering on the polystyrene, but after the tape test I could get a bubble to form on the surface, when breaking the bubble the primer could be peeled off, with some resitance, but this peeled off cleanly like sun burnt skin.

                                                            I think this would be ok if this was in an area where no rubbing or touching was involved.

                                                            I dont know what it does with temperture yet I will still complete that test later.

                                                            I will try the Vanillacryl if I can get it here, or import it.

                                                            Uncle Ken what tests were done on the primer you have down under.

                                                            Thanks, keep you all posted.

                                                            Glen

                                                            #1068365
                                                            SUPER ’63
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                                                                hi glen,

                                                                i’ve been working on and off in the automotive repair industry for many years, i’ve had to to support my custom painting as there’s not a great market for it where i live. anyway, i’ve read all your other replies, and the ones mentioning water based primers are the most logical. the only thing is, you will find it very difficult to find any modelling/hobby primers which will actually do the job well. you will need an automotive refinish product. i have used many primers from many manufacturers over the years, and currently use glasurit. a german company of the highest quality paints. they do a water based primer filler which gives a high build, onto which you can apply any paint or lacquer. steer well clear of plastic adhesion promoters, they wil definately attack the polystyrene. their job is to effect adhesion without sanding, and they do this by eating in to the substrate/ surface. in my opinion, if you want the toughest possible fuel proofing that will give an excellent ground for any primers or paints, coat the entire structure with a two part epoxy. you could even do this with a brush and readily available epoxy like araldite. obviously you need to have the patience to sand the surface smooth after drying. but if you love your model this is a small price to pay right? and this way you don’t need to get involved with spraying epoxy. hope this helps

                                                                marcus

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