Paint/Primer won't adhere properly. Please help.

Hey Venom - a couple of comments.  Maybe the primer hadn't fully cured before you hit it with the acrylic.  And a general comment - I've had issues with MM acrylic being "inconsistant" bottle to bottle.  I will admit I don't care for it much, so the "problem" may be more on me than the paint.  But a potentially easy try is to get a fresh bottle of MM.

Sorry - I know that's not much help...good luck!

I agree with the primer not being cured fully. Not a huge fan of Krylon but my go-to primer is Rustoleum brand. Krylon is garbage in my opinion.

I switched some time ago from automotive primers and Rustoleum, to Tamiya's acrylic primer.  It's more expensive by volume, but it seems to cover better and the small amount goes farther, for me.  But regardless of the paint, I agree with the others, in that you need to give the primer time to cure.  I will let parts rest for four hours at least, and I usually let them sit overnight.

Also, do you clean the kit parts first, to remove mold release agents?  That will help any primer adhere.  I wash my kits in warm water with a couple drops of an automotive de-greaser (Super Clean) in it.  I know a figure modeler who even uses a mild abrasive soap on resin pieces, to roughen up the surface ever so slightly and increase the "tooth" of the primer.

Hope that helps!

Brad

I've had MM acrylic lift when removing tape masking so I avoid using it and any acrylic primer cause they don't bite into the plastic as good as solvent ones. The exception is with Tamiya acrylics. They seem to work out very well.

I'm surprised the Krylon came off that easy caus it's solvent type and should garb on good. A couple of questions:

How long did you let the primer cure?

Was it a new can?

Tamiya primers, either the white or grey are excellent solvent types.  

My guestimate also is that the primer did not cure. It sounds like you applied the paint immediately or shortly after applying the primer. With dissimilar layers, enamel primer and acrylic paint, that is a bad idea.  I always let primer coats dry and cure at least overnite before beginning base colors. And yes, MM Acrylics have terrible adhesion properties as well as poor scratch resistance in my experience.

What was the temprature when you painted? I have had similar problems with both not letting everything cure enough and spraying in lower than desired tempratures.\

Steve

What I find very intertesting is how well MMA paints

stick to chrome airbrushes ??

Dash8

What I find very intertesting is how well MMA paints stick to chrome airbrushes ??

Any paint will stick to chrome airbrushes when dried out/not thoroughly cleaned properly.

I've found the same as others have.  The paint has to not only dry to the touch but cure properly.  Same thing with some glues.  That's why I work on more than one build at a time.

Jim  

There is a thread going on in the painting and airbrushing forum currently on primers. It is not primarily on adhesion, but it may be of interest to you anyway.  That forum is an excellent one, worth monitoring.

Dash8

What I find very intertesting is how well MMA paints

stick to chrome airbrushes ??

 

Same here.

Maybe i'm really lucky. i don't wash anything unless a kit review specifically mentions it. i use ACE Hardware NOW gray primer on most everything. i probably let it sit a day but i am sure i have primed in the morning and painted late afternoon. i use Vallejo, Vallejo Air, MMA, and Tamiya with no problems. i let it sit a day or somethimes put it under a 100w light bulb to dry. i have masked with painters' tape, Tamiya tape, and silly putty with no lift off. i have had trouble with whites but that appears to be common. i also don't clear coat before weathering with acrylics, pastels, powders and/or oils with no lift off.

So it must have been that I didn't let the primer fully cure, because I tried it again and let the primer sit 24hrs and the paint stuck after that. This seems odd to me though, because I let it dry about 3hrs the first time which has worked in the past for me on other models. Maybe it's that my appartment is colder this time of year and it took longer for the primer to cure.  Either way, thank you to everyone who gave me feedback on this issue. 

I've had that problem in the past with Trumpeter kits... even with hefty cleaning I would get acrylic primer/paint lifting.

These days I usually lightly sand larger surfaces and/or parts that will require masking with fine grit, then hit them with rattlecan Tamiya surface primer (I usually airbrush prime small detail parts), lightly sand again and airbrush the main color(s) with acrylic.

I don't usually bother to wash anything unless it's obviously slick with relase agent; most mainstream kits (trumpter especially) seem to be very well cleaned OOTB.