Strange paint problem

[Fletch]

I am working on a tooned Jaguar space ship and went to paint the wings and this happened. I used Duplicolor auto primer and Duplicolor gloss black metallic laq. Same stuff I have been using for 30 years. I have been spraying paint since 1960 at least and this is a new one.

Applied the first coat of gloss and within one second of hitting the part the edges started turning to flat leaving the middle still gloss. This was both sides. So I waited a while and sprayed again with the same result. Waited till the next day and tried again and the same result again.  It goes on glossy but within one second starts to fade to matte around the thin edges. Looks really cool while it happens. The edges of the wings are really thin and the fading is just around the thin areas but this is something I never ran across on any car models. I think I will just leave it but I still do not know why the thinness of the part should make the paint do this.

This happen to any of you?Attachment Deleted

[modelcarfan]

It did happen to me once, and that was during the cold weather and the environment was humid, so I stripped it off and do again.. but I warmed up the paint in hot water prior to spraying the model pieces. I put the paint in jar already attached to the airbrush and jar set in hot water for about 5 or 10 min.. then when I m ready, I took out and just gently stir around the paint and spray. If you use the aerosal can spray, I would do the same just shake it well and then prop in the hot water for same amount of time.

Hope this helps.

[Fletch]

Hey thanks modelcarfan - It never gets humid here and I warmed the cans up before spraying like I always do. Shook them up for at least 8 minutes while I was waiting for something else so they were all shook up and warmed up and ready to go! It has to be the thinness of those parts for some reason. I forgot to add that I sprayed a whole bunch of other parts at the same time (with the same paint)  but they all turned out perfectly glossy. It was just these two thin wings that I had trouble on. Weird.

[TooOld]

Very weird indeed . You've ruled out humidity and it's hard to imagine the thickness of the plastic is causing it , unless there's some chemical reaction that's more concentrated in that area of the parts .
When you repainted did you sand and reprime over the first coat of paint ? Seems like that would have cured it .

The one thing I've noted is the last couple of times I've had paint issues it was with rattle can Gloss Black , once with Duplicolor and the other was Tamiya . Never happened before or since so I just chalked it up to bad prep of the parts but I don't really know for sure . It happens to all of us sooner or later .

[steelwoolghandi]

I have had this happen to me but I was using Gloss Krylon Fusion Paint and no primer and it too was thin plastic to thick. No matter what I did I could not get it to gloss up like the rest until I stripped it and primed it real good and then shot just Gloss black on it. Might just be the paint you are using is a bad batch and is reactive?

[Starryeyes]

Solvent entrapment Fletch.. duplicator has been in the process of changing propellants which help suspend the solvent.. This happens when the paint is applied then the clear is added.. The solvent is trapped in the paint from flashing too quickly and when the clear was applied it reactivates the bonding agent in the paint where the solvent is trapped thus contaminating the clear coat... Re applying the clear only added to the already contaminated clear from th day before... This isn't an exact explanation but it gives you an idea of what happened... After prepping Try a re-shoot of the paint and allow ample time to gas out.. Then try your clear again I'll bet it will be just fine..

[Fletch]

I did not clear this part yet.

The reason I think it is the thickness of the plastic is because where it is fading it is literally razor sharp thin and where the dark area shows is a lot thicker plastic. All the other parts I sprayed were fine and beautiful.

 Gloss clearcoat was not needed on those other parts.

I do not like Duplicolor gloss black as it sucks. But their black metallic is great stuff and I have used it for years.

I did not sand and reprime as it is laq and thin enough for several coats without getting too thick.

If you look real close around the edge of the dark area you can see what looks like a halo of another color kind of like the way a chrome exhaust changes color with the heat. So I will just keep it this way as it looks cool and not clear it.

[wardster]

When the end result looks cool, "I meant to do that!" fixes a whole bunch of things, doesn't it?!

[modelcarfan]

Hmm, after looking at the picture... it appears that the affected area might not have enough gloss paint over that. Give it one more shoot to cover the area and see what happens. Doesnt have to be entire area.. just the area that is light. Maybe it should cover some. Try it and see what happens.

[Fletch]

HEY Ward!      You put the words right into my mouth!

I meant to do that!

I just posted the model that the wings went on over on the "finished toons" thread. I left the wings as they were.