Best Primer for Acryl

Sounds more like that section had a contaminant on it like oil from your fingers etc.  From my understanding Model Master Acryls can easy to lift off.

The one primer I've used with great and predictible success every time is Tamiya's fine (gray) primer.  Its a rattlecan which is harder to control, but it gives a nice, even, smooth coat.  I've tried Model Master primer before but haven't had any luck with it for some reason.

Mr. Surfacer is nice and can give great results from what I've seen, but putting it through the airbrush was a chore.  I still haven't found a good primer:thinner ratio and get a lot of "cobwebs".

I routinely used Tamiya's primer under Tamiya paints, Model Master Enamels, and Vallejo acrylics without issue.  Haven't used Model Master Acryl very much though.

Hope it helps!

Brian;

Thanks.  I thought I had given it a soak before starting, but I need to scrub it down a bit before the primer coat.

I don't like those cans as I can never seem to get a smooth finish.  I can't bring myself to use them indoors in the hobby room and outside is always got "stuff" moving around in the air.  I saw the FSM video on decanting spray paint, so I may give that a try and see how that goes with an airbrush.

It stinks to get your masking right and get a good job and then peels the other color that you masked and then you go back and forth.  I am going to try a drafting type tape next.  Can't think of a tape with less tack than that.  Interestingly, I asked Testors about it, and they recommended using wet paper to do the mask.  Said you can only do sections at a time before it dries, but it might be worth a try.  Seems a little "out there" though.  Not sure how you get wet paper to stick to curves and the like?

John

Well I cant say it is the "best" primer, because I really do not use any others, but I do like Humbrol's primer in their enamel line in the small tin. Stir it thoroughly, mix with your preferred enamel airbrush thinner (I prefer Model Master Airbrush Thinner) to the appropriate mix for airbrushing, and apply it with your airbrush. Works great for me every time.

But yes it is frustrating to have to prime with an enamel in order to give the acrylic something to stick to and not have to worry about the MM Acryl paint lifting off when masks are removed. Sort of defeats the whole reason for going acrylic regarding chemicals and clean up and all that nonsense.

So for the extra credit part of the program; How do you fix this mid-build?  I am shaking in my boots about taping over the just painted areas to put the other color/coat back on and then when I take the tape off I have just peeled the newly painted section and I am in a circle so to speak.

John

Well you can either mask off the newly painted area once it has had time to dry and cure, and airbrush again, running the risk of the same thing happening when you remove the new masking. Or you can touch up with a fine paint brush by hand.

99 times out of 100 when I do prime it is with Mr. Surfacer 1200.  Thinner with lacquer thinner it sprays just fine without any AB problems at all.  Has some nice bite to it so it has never peeled.

Sounds like (as noted by Brian) a surface contamination problem in this case.

I have used MM acryal for a while and so far not had your situation occur. [note:  it is not my  skill so much as my dumb luck]

I use  Tamiya Tape and give at least 24 hours between colors. 

That said, the use of Post-it notes  or the wet paper trick can also give you a quick mask for spot touch ups.

For primer I have used what the others have used, including  automobile primer and have Alclad II primer for a future project.

So don't give up keep trying different combinations to find your "go to" combination. 

spray lightly and smoothly and may your runs be only in baseball.