Primer & Paint question - Tamiya & Model color

Did you brush or spray the Vallejo Model Color ? And if sprayed, how did you thin it, with what products.

What color is the primer ? If not white, then clearly you are seeing plastic where the paint pulled off.

Vallejo is (in)famous for its poor adhesion. That's likely the main issue. 

  The Vallejo gets my vote too for being the culprit.

I have to say it's more likely the Vallejo Cavalry Brown than the Tamiya Fine Surface Primer, too.

You didn't say how you applied the Vallejo paint, but if it's Cavalry Brown from the Model Color line, and you airbrushed it, that would be another mark in my mind that the issue is with the Vallejo paint.  Their Model Color line can be airbrushed, it's true, but then, a lot of paints can be applied with an airbrush.  But the Model Color line is made for brushing by hand; it's a favorite among figure painters.  Vallejo's Model Air line of paints is formulated for airbrushing-though it can be applied by hand.  But the Model Air line has a selection of adjuncts to use when airbrushing, which increases the complexity of the process, in my opinion.

I have a dozen or so Vallejo Model Color paints in my paintbox, and I agree that they are more sensitive to scuffing, chipping, and other kinds of wear, as I handle a piece, until I can seal the color coats.  I use Tamiya's Fine Surface Primer, and have no problems with that primer.

Oops - i knoew i foprgot something!!  I airbrushed the VMC calvary brown.  10 drops paint, 2 drops thinner and 2 drops flow improver - all Vallejo paint/thinners/flow improver.

Maybe i shpould hasve done the Air line of paints....

Sorry to say, I think you're going to get mediocre results from Vallejo, whether it's intended for airbrushing, or not. Model Color, Model Air, Game Color, etc. are all notorious for poor adhesion. They're fine for figure painters, who generally don't mask or handle their work very much at all. Other kinds of modeling, not so much. 

I use Vallejo paints pretty much exclusively on my kits and while I've never had an issue with masking peeling the paint off I have had issues with it chipping easily and it wouldn't sand worth a darn.  Wil have to jump on that bandwagon that it is likely that.  However...

I discovered it doesn't harden properly at room temperature.  I've taken to curing everything in a box at 112F.  After a several hours in there it hardens nicely. The paint is much more durable and can be sanded afterwards. 

My paint dryer is nothing more than a simple cardboard box with a 60W incandescent bulb in it.

PhoenixG

I use Vallejo paints pretty much exclusively on my kits and while I've never had an issue with masking peeling the paint off I have had issues with it chipping easily and it wouldn't sand worth a darn.  Wil have to jump on that bandwagon that it is likely that.  However...

I discovered it doesn't harden properly at room temperature.  I've taken to curing everything in a box at 112F.  After a several hours in there it hardens nicely. The paint is much more durable and can be sanded afterwards. 

My paint dryer is nothing more than a simple cardboard box with a 60W incandescent bulb in it.

 

I agee, especially on the heat aspect of your post. It also helps to put the first couple of coats on very light and heat set those with a hair dryer to flash dry. Also in my experience , with final heat setting in a dehydrator, I only do 30 minutes @ 110f. Great improvement in scratch tests were revealed in my testing this method.And others supported my findings by having done something similar as well.

Also we noticed right in this forum several folks not complaining about Vallejo and it was found that all who were complaining were just room drying. That left the paint with a tacky or rubbery feel, even weeks later. Those of us heat setting got a harder shell finish. I personally have no complaints . And I don't even thin mine with Vallejo products, but I heat set the stuff..

Still, on a large ship hull ( not saying the OP hull is large) I probably wouldnt pick Vallejo. I'd probly mix the color myself from Rustoleum 2x enamel, decanted. Thin it extra with lacquer thinner and spray it with my Paasche H airbrush or even my LVLP touch up spray gun. Everything levels out nice with that method. Over lapping patterns melt in nicely with enamels. Doesn't have to be 2x, but you can't beat the quantity lol. Just sayin.