Question on paint mistake

USSBalao

Something similar just happened to me. I'm building a Revell 144 scale B-52G. I painted it overall neutral gray MM enamel, close to FS 35237. I then airbrushed a sealing coat of Future Floor Polish, thinking that this would help to stick the Frisket paper I intended to use to outline the camouflage. For the camouflage color I used Vallejo Model Air color tan green hemp, the recommended color for FS 34201. I sprayed a thin first coat on the model, let it dry for a couple of minutes, the sprayed the second covering coat. Things looked good, until about 5 minutes into that second drying process, when the paint started separating from itself, and spider webs begain to appear. The paint did not go into any panel lines, but rather refused to bind itself there al all, so the panel lines showed the original grey color. What a mess! 

Not sure exactly what happened, but I think it has something to do with the combination of Future Floor Polish as the surface coat, rejecting the acrylic Vallejo paint. But why would one acrylic reject another acrylic? Did I comment some unpardonable sin? Can anyone help me out? Thanks. 

I have to second oldermodelguy on his observation.  Future can be used to seal a layer of paint, as prep for weathering with washes, for example, or as a gloss coat to provide as smooth a surface as possible for decals.  But I wouldn't use it to adhere something I intend to remove later.  Frisket film ought to stick on its own pretty well, but I would have used thin rolls of poster tack to put the masks down.

Beyond that, I have to say that the more comments I read about Vallejo's Model Air line, the less I am inclined ever to try it.

USSBalao

Thanks for your admonition. I think you're right about the problems with using Future/Pledge as an intercoat. Lesson learned. And, perhaps more importantly, you helped me to better understand why, when using Future over enamel, the surface always seems to be gritty, like a heavy orange peel, and not smooth like the initial enamel coat. 

 

With enamel if I ever used any clear it was generally also enamel. Back in the day I used Pactra or sometrimes Testors. These days if I'm using enamel it's probably on a classic car to which the color coat is the top coat. For armor or things I will decal I like lacquer or acrylic products and those seem to play together pretty well. But always test your procedure, I just tossed out some of the most beauitiful presription bottles you have ever seen lol !!! Two years of recoating of various paint trials, some polished lacquer etc. I've still got a gallon freezer bag full of unpainted ones waiting trial paint jobs. Over the last couple of years, 2-1/2 actually I went to town on learning the ways of acrylic paints to include craft paints, so much of those bottles were from that prolonged test session. I learned to like acrylic and if I needed a clear intercoat I found lacquer to do well fwiw. Just sayin.

Thanks for your admonition. I think you're right about the problems with using Future/Pledge as an intercoat. Lesson learned. And, perhaps more importantly, you helped me to better understand why, when using Future over enamel, the surface always seems to be gritty, like a heavy orange peel, and not smooth like the initial enamel coat. 

USSBalao

Something similar just happened to me. I'm building a Revell 144 scale B-52G. I painted it overall neutral gray MM enamel, close to FS 35237. I then airbrushed a sealing coat of Future Floor Polish, thinking that this would help to stick the Frisket paper I intended to use to outline the camouflage. For the camouflage color I used Vallejo Model Air color tan green hemp, the recommended color for FS 34201. I sprayed a thin first coat on the model, let it dry for a couple of minutes, the sprayed the second covering coat. Things looked good, until about 5 minutes into that second drying process, when the paint started separating from itself, and spider webs begain to appear. The paint did not go into any panel lines, but rather refused to bind itself there al all, so the panel lines showed the original grey color. What a mess! 

Not sure exactly what happened, but I think it has something to do with the combination of Future Floor Polish as the surface coat, rejecting the acrylic Vallejo paint. But why would one acrylic reject another acrylic? Did I comment some unpardonable sin? Can anyone help me out? Thanks.

 

First I'll just say I don't like to use Future/Pledge as an intercoat. It's really unclear as to what will take to it properly. And I personally would never use Future/Pledge over enamel anyway. But more than just that fact the two substances have totally different drying rates. Now add Vallejo on top of that with yet another personality. Finally, I don't do anything like this without fully testing on some kind of junk piece ( I use prescription bottles a lot as test subjects from primer to top coat)...

Had a random basic thought last night.....

Are you giving the Revell Aqua a proper stirring, not just shake-shake-shake the bottle?

Acrylics can be finicky, some brands and even certain colors within the same brand can be more prone than others to a settling of sludge at the bottom of the container.

I'm not the greatest at always heeding this advice myself, but when I do I find I have less problems and I'm trying to get better at it.

the Baron

I think your paint is too thin. That's what I have seen, when I've thinned mine too much. It looks like little accumulations of pigment separated by way too much carrier.

This makes good sense. You stated that you don't think your paint is too thin. I'm tending to agree with The Baron, it looks like it is.

Also, back to adding the Vallejo Flow Improver again, we have no idea what chemistry is going on. The Vallejo product might be acting to separate the pigment and carrier (as Brad suggested) without making the paint appear too thin.

Just musing. Maybe or maybe not.

Something similar just happened to me. I'm building a Revell 144 scale B-52G. I painted it overall neutral gray MM enamel, close to FS 35237. I then airbrushed a sealing coat of Future Floor Polish, thinking that this would help to stick the Frisket paper I intended to use to outline the camouflage. For the camouflage color I used Vallejo Model Air color tan green hemp, the recommended color for FS 34201. I sprayed a thin first coat on the model, let it dry for a couple of minutes, the sprayed the second covering coat. Things looked good, until about 5 minutes into that second drying process, when the paint started separating from itself, and spider webs begain to appear. The paint did not go into any panel lines, but rather refused to bind itself there al all, so the panel lines showed the original grey color. What a mess! 

Not sure exactly what happened, but I think it has something to do with the combination of Future Floor Polish as the surface coat, rejecting the acrylic Vallejo paint. But why would one acrylic reject another acrylic? Did I comment some unpardonable sin? Can anyone help me out? Thanks.

I have Vallejo model air, never had any troubles like this in my first model.

I just bought revell paint and this started happening. So what you wrote about mixing things with vallejo flow improver does make sense.

Funny enough, even after priming, the same effect showed up, but to a lesser degree.

I did try not adding flow improver and results did get better. I do want to try it some more, just to make sure.

@The Baron, I don't think the paint is too thin, I've seen the effect of thinning down a paint too much and it usually accumulates small puddles near the edges of the plastic. But that is not the case here. I'd say the paint seems rather "Oily" IMO. Still, I'll try and let you know.

PS. After adding one or two extra coats, the paint gets much better and the effect is almost imperceptible.

I said it in your original post, but I'll repeat it here for those who didn't see the other one.

I don't think priming or not priming, or other surface prep, is related to this.  I think your paint is too thin.  That's what I have seen, when I've thinned mine too much.  It looks like little accumulations of pigment separated by way too much carrier.

Thanks for providing more info, helps troubleshoot the problem.

Decanting: I guess this usually means transfering a liquid from one container to another without transferring any sediment. In modeling, I've always taken it to mean transferring paint from a spray can (you'll hear folks say "rattle can") to a jar so it can be used in an airbrush.

In the other thread, you mentioned mixing Vallejo Flow Improver with the Revell Aqua. I'm going to guess that is farily likely to be your problem. Here's what I know about the Revell and Vallejo Model Air:

Revell: absolutely nothing

Vallejo Model Air: a mysterious concoction which does not like to be mixed with pretty anything except Vallejo Airbrush Thinner (new formula) or Vallejo Flow improver.

In my experience, Vallejo is the wrong product to attempt to creatively mix with other stuff.

If I were you, I'd do a test spray of Vallejo Model Air right out of the bottle on a piece of junk styrene and see what happens. Counter-intuitively, Vallejo Model Air performs best at 20-25 PSI. If you get the same results, we'll try something else.

If you are using Vallejo Model Color, not Model Air, that would complicate things. Let us know, ok?

Thank you KnightTemplar5150, that's some wonderful insight on the issue.

Greg, thanks for bringing up my original post. Sorry, I completely missed my original post. I posted in a different section and pretty much lost it and thought it hadn't been posted.

>> I'm baffled by your decanting statement.

Don't read too much into it, just my mind running wild here. I just thought that if I take like more than 10 minutes while airbrushing, maybe parts of the paint will go down inside the airbrush cup while others go up. Not sure it is possible while painting, maybe it occurs only after a few days within paint bottles?

I'm still a newbie on this subject so I am testing the issue, changing all different variables like priming, airflow improver and so on.

Your original post  has lots of replies.

http://cs.finescale.com/fsm/general_discussion/f/9/t/184720.aspx

Dad blasted finicky hot link tool!

I just spent a while reading about Revell Aqua Color. Seems to be a fine paint line. They state it can be thinned with water, then state it is best not to, rather to use their own propietary thinner to avoid strange results.

I'm not making that up. Look here.

I'm baffled by your decanting statement. I wonder if you could explain it a bit more? Decanted from what? Spray cans? If yes, are you sure they are not enamel? I also saw on Revell site that they have both acrylic and enamels in the paint line. If you decanted from an enamel rattle can and thinned with water, that would explain a few things.

More info would be great. We'd all like to help you solve this.

PS, priming is good. IMO, not optional when using acrylics. Key words, "IMO".

Edit: I wrote this late last night without reading KnightTemplar's above post throroughly. I agree with everything he said, and sorry I repeated some of the things he already said. Sometimes I get my panties all in a knot when folks post stuff ignoring what others said. I get embarrassed when I do it myself.

Another thought I had later was don't feel alone, I had pretty much this same effect happen last year as I a playing with Mission Models paint for the first time after reading rave reviews for a year. I got frustrated, never tried them again, and still don't know what happened. (in my case, I'm pretty sure I did something dumb based on all the raves I read about the product)

Here's two cents worth of nonsense.

- Priming is a norm for me, but it becomes a priority when working with acrylics. By nature, most of those paints are fragile when compared to enamels or lacquers. The naysayers object to this practice because they say it obscures detail. I just wonder how thick they think they need a primer coat and just go about my business as usual.

- Cleaning and degreasing a kit prior to priming is again a standard part of my process. There are those who argue that it's not really necessary, but I'm too stuck in my ways to change. Once you've had to deal with paint peeling off of your work, it's a case of once bitten, twice shy.

-Anytime you introduce a new element to your paint mixture, you increase the number of variables you have to address when you're trouble-shooting issues. Flow improver is great for dealing with dry tip issues, so that's about the only time I'll break it out, otherwise the simpler I keep my process, the better.

- While a few companies advertise that their paint can be cut with water, most of them fall short in practice. Revell has a proprietary thinner for their Aqua line, which coincidentally contains a wetting agent to improve paint flow. Pretty sure you'll see a world of difference in how your paint performs if you try it out. In the least, the thinner will hold the paint suspended in solution a lot more effectively than plain water.

Any one?

I have the following guesses, although I am not quite sure it is any of the following:

- Not priming (Still I have seen people that don't prime, not sure it was necessary in this case)

- Not washing the plastic correctly agains mold release agent (I did wash it, but maybe no thoroughly enough?).

- Using Flow Improver with my airbrush (Paint becoming too oily maybe?)

- Something wrong with thinner? (Using water with revell aqua at wrong amounts for airbrushing maybe?)

- Decanted paint on airbrush (I did mix it, but after a few minutes maybe the oils from the paint went down and made that part oily?)