Airbrushed Vallejo rubs off or scuffs easily

Here is the link to the tread I had been reading up on. For some reason it won't show up in the post. 

http://cs.finescale.com/fsm/tools_techniques_and_reference_materials/f/18/t/183461.aspx

You must be shooting Model Air because Model Color would backfire on that alcohol. But anyway, Vallejo can be a bit softer to surface scuffing than some brands and while I have not shot that particular color, I haven't had trouble with it scuffing or chipping back to the primer coat in general with VMA. That said, while the paint may not look settled people have said you really need to either drop a little stainless nut into the bottle so when you shake it you get full agitation. Or else get a stirring stick of some sort in there and make sure it's really mixed well. The bottle dropper top pulls right out on those bottles.

Additionally I fairly often scuff stynylrez with 000 steel wool, this may offer a little extra bite. But I don't always do that and haven't had any trouble with really any top coat.

Best I got for ya , maybe someone else will chime in with more.

Thanks for the input oldermodelguy. I can confirm that is it Model Color 70.961 Sky Blue. Never had an issue thinning it with the mixture from the link above but then again that could be the reason why it rubs off so easily. 

I have put agitator balls in all my paints to improve mixing. I will give your suggestion of the steel wool a go sometime.  For the rest of this project I am sticking to the actual Vallejo Thinner to remove the DIY thinner from the equation completely.   

Like I said in my post though, it is wierd that it is happening now after using it without any issues before. I have airbrushed several models with the Vallejo Model thinned with the DIY thinner as well as Model Air colors ( not thinned ) and have been surprised at how durable they can be after cured properly. I once had my girlfriend put all the painted parts of a kit in a box together. I was sure they would all be scratched to some degree but they were all unscathed, and this was painted parts lose in the box as well as some sprues. ( She just didn't think anything would happen since they were dried ) 

I appreciate anyone elses input but I am gonna spray some scrap plastic with primer and then airbrush it with the Vallejo Thinner and then another scrap piece with the DIY thinner just to see if I can duplicate it this issue. Hell, since I'm already at it I may as well do a third scrap piece and try your steel wool trick. 

I make a thinner very similar to your home brew and have used it in MA to shoot it through a .25 nozzle and it works fine over stynylrez ( very smooth coverage sticks fine). I tend not to airbrush MC. Maybe that particular bottle is bunged up or something, where you've had no issue with the others.

Good to hear the alcohol didn't gel up the MC, I've heard bad reports on that though. I think I'll stick with MA though, most of the time I don't thin it at all but I had a tan I cut a little bit and it shot fine as I already mentioned....

Ya just lightly scuff the primer, it might make the difference.

I was skeptical at first as well about that DIY Thinner working with MC paints because of the alcohol as well but since it is pretty diluted then it's prolly why it didn't react to it. Back in the day when I was starting to learn about all the different paints my thought was that any acrylic was water based. With that misconception I screwed up a number of times with paints like Tamiya or Model Master as far as what you could use to thin them. 
When I started the suggestion at the time was to thin MM with Windex and it was on another forum that I read about people thinning their paints with 90% rubbing alcohol, not paying attention to the kind of paint they were referring to. Mixed some alcohol in my airbrush with some MC and it resulted in this gummy mess that took me nearly 40 mins to completelely clean. 

It will probably be a few days before I can see the results of my tests but I will post an update once done. 

It's so funny I had the same issue with the same paint and same color. It rubs off easy afterwards even after drying for over a week. I did not have an agitator ball in it but it does now so we'll see if that helps?

   I swapped over my paint system to Valleo, I also noticed how soft they are even after a long cure time. I do not thin, straight from the bottle around 20psi. I DO shake the paint well before use. I primed some parts with Tamiya white and others just shot the color down, did not seem to make a difference in final durability.

   My thought process was to try a Testors gloss and dull coat to see if it locks the color coat down. It shoud as the clears are lacquer vs acrylic.

I had to end up sparying down a clear coat and moving on @armornut. I am kinda obsessive so I spent two weeks trying different thinners, different number of coats, etc. I even went and bought another bottle of the same color and same results: It just scuffs very easily. I even went as far as spraying 6 coats on a test piece, let it sit for 3 days to dry and then 24 hours in a food dehydrator for a day at 95F and the same thing happened. What it so bizarre is how I could handle it and nothing would happen but I would pick up the piece a moment later and all these scuff marks showed up. 

I have sprayed Vallejo for several years but admittedly this was the first time I had sprayed that color. When it kept happening I swore that I might be doing something wrong without evern realizing it. Did several Google searches but could not find anything aside from the usual cases of the coats being too thin or the paint being thinned too much or with the wrong kind of thinner. 

Thanks for validating that I wasn't crazy @JimLo, at least not completely.   

Vallejo (VJ) is twitchy, some colours more than others, although I had no problems spraying a 1/24th Fiat 500 in VJAir Sky Blue, metal model was sprayed with Halfords (UK) acrylic rattle can primer first.

Conditions have to be near perfect with VJ, model primered, Humidity, paint properly mixed, then thinned, then VJ Airbrush Flow Improver (essential!).
It can remain soft for days/ever!

Another point to remember is that if over-thinned, it won't stick to anything at all!

I concur that VJAIR is poor (= gloopy rubbery mess!) with any alcohol based thinner, VJColor more so!
I've done the 'Home-made' IPA based thinners, which don't work with VJ! The initial cost layout was high, for no real benefit to me, as half of my paint stock was VJ, although it works fine with Tamiya.

For VJ, I have had more luck with Mr Color Leveling thinner, and Medea & Vallejo branded airbrush thinners.

I have also used Original Future/Kleer as a thinner for VJ Poleurethane Black primer, at 10%, which had the benefit of 'hardening' the VJ primer, allowing a little reworking, and imparted a little sheen.

Should I need to do another Night Finish on a UK Bomber/Fighter, I will use Badger StyNylRes Gloss Black, so much better!

My warpaint of first choice nowadays is Badger StyNylRes, then Tamiya, then Mig/AK.