tollboothmusic Posted February 10, 2014 Report Share Posted February 10, 2014 Hi peeps I'm having fun finding my feet in painting and am doing ok. I can get to a stage with a model and think 'yeah - it's ok, it's vaguely finished' and i take the plunge and decide to varnish. i like matt finishes so i'm using a Vallejo matt varnish (17ml pot type), but finding that from time to time after i go back to it after maybe a day or two, it seems to have lifted some of the base coat back to primer. At first i thought it was a real noob mistake and i wasn't checking my model properly for bits i've missed, but i'm getting a lot better at layering and highlighting now and so it's really odd for me to miss a section down to primer anymore, but it's still happening at varnish. I started off using the varnish direct from the pot as i didn't know if it was designed to be thinned or not and wondered if it was too thick when i applied it and the brush was dragging somehow and tearing the base coat off. So I've started adding maybe 25%water to the varnish so it's taking longer to dry, but not i'm worried i might be overly rehydrating the base coat and that's causiing the issue. Anybody any experience of the same thing. Any ideas? Too thick/too thin Applying Varnish w brush a bad idea in general? Do i need to look at spray varnishes? Thanks everyone - thoughts and comments appreciated. Paul D (Sorry, don't have an example to hand i can post as pic) Quote Link to comment Share on other sites More sharing options...
Fenton Crack Posted February 10, 2014 Report Share Posted February 10, 2014 Hmm. I use Vallejo matte varnish all the time, both with a brush and an airbrush and have never had the problem. The one thing that any matte varnish will do is "frost", if applied in the wrong humidity/temperature or applied too heavy. Is it possible you prime in white and you are getting a frosting on your clear coat (which, of course will appear white) and it just seems as though you are seeing the primer? If that is the case take some gloss coat over the area (should not matter either way if you are going to need to strip the model for repaint) and if the white goes away or lessens, it was a frosting issue. Quote Link to comment Share on other sites More sharing options...
Sholto Posted February 10, 2014 Report Share Posted February 10, 2014 I had this happen once with Testor's Dull Cote, applied by brush straight to a model. I was using too much and it dissolved the paint. Matt varnish is in my experience best applied over a gloss coat. It is stronger than just matt on its own, and the gloss is much less likely to interfere with the paint. Quote Link to comment Share on other sites More sharing options...
Wings Posted February 10, 2014 Report Share Posted February 10, 2014 The other thing to check is if your paint is entirely dry - lots of people wait to varnish the next day to make sure. If it's still damp that might make it more likely to be damaged in applying the varnish? Quote Link to comment Share on other sites More sharing options...
Fenton Crack Posted February 10, 2014 Report Share Posted February 10, 2014 I had this happen once with Testor's Dull Cote, applied by brush straight to a model. I was using too much and it dissolved the paint. Matt varnish is in my experience best applied over a gloss coat. It is stronger than just matt on its own, and the gloss is much less likely to interfere with the paint. I would agree with glossing prior to the matte. Gloss coat is generally harder and more durable, it's yet another layer of protection, and if your model is taking exessive "finger wear", the spot should get shiny first, as the matte coat wears, letting you know you have a problem prior to wearing into the actual paint. I use the matte only to deshine, and use the Vallejo matte in just very thin final coats (thinned closer to 1:1 than 2:1 with water) to ensure there is no frosting. I used to apply it via airbrush, but was prone to occasional frosting that way. Quote Link to comment Share on other sites More sharing options...
tollboothmusic Posted February 10, 2014 Author Report Share Posted February 10, 2014 hey peeps thanks all - the idea of glossing first is a great one - will try it on next batch of victims. it's actually happened on both white and black primed models. I used to prime everything in white when i did my first few as i was paranoid about missing bits with base, but i've taken the plunge and started priming in black, in fact the problem has mainly been with the black primed ones. i think reading the comments, i wonder whether it is most likely that i'm not leaving the finished model long enough before painting. I can get a bit impatient sometimes, one of the reasons some of my models have come out a little 'muddy' in the past as well. I shall try all of your suggestions. thanks guys paul d Quote Link to comment Share on other sites More sharing options...
daddy4count Posted February 12, 2014 Report Share Posted February 12, 2014 It sounds to me more like an issue with adhesion between the primer and color coats... Paint tends to shrink when it dries, which im most cases is not an issue... however if the adhesion between lower coats is not strong that shrinkage will lift the coats beneath it. In the paint biz this is known as "delamination" What kind of paints are you using on the model? Brand and type of primer, what kind of color coats, etc? My guess is that it would have more to do with that than the matte finish itself? Quote Link to comment Share on other sites More sharing options...
tollboothmusic Posted February 13, 2014 Author Report Share Posted February 13, 2014 hey d4c the paints are a mix of Vallejo Model Colour & Game Colour, the primer is Vallejo Black Primer, and the varnish is Vallejo Matt Varnish. The models were washed and dried well before painting. any ideas gratefully received. paul d Quote Link to comment Share on other sites More sharing options...
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