Disaster with Acrylics

I was happy with my acrylics from tamiya, but disaster struck.
I was painting my awacs from airfix. Everything went according to plan. But the next day I could rub the paint of the model. This is the second time that something went wrong with acrylics. I go back to Humbrol I know that will stay on my models. I have cleaned the model before painting. The strange thing is that the acrylics stay perfectly on a heller model. But not on an airfix model.
[xx(][:(!][V][?][?]

Interesting…I myself have never had a problem with Tamiya acrylics. You say this is the second time it’s happened to you…were they both Airfix kits? Makes me wonder whether it’s the type of plastic they use in production having an adverse effect with Tamiya paints.

It was one time with Tamiya the other time it was with an other brand of acrylics.
The only plastic that gave no problems was a model from Heller.

Painting my model trains and wagons with acrylics works fine, and I will keep using acrylics for this.

it happens with me too. just prime/sand the model first then apply tamiya and then appply gloss/flat coat. works everytime. repeat as nessisary.

With what do I need to prime? Can you tell me that unnamedplayer. Because I still like to stay with the acrylics.
Any help is welcome.

to prime: first, wash the model in lukewarm water with soap. let it air dry, or if u have airbrush, use it to help the model dry. then sand sand sand. then spray primer, grey is bests. primer will show all errors. sand errors. spray again. sand again. repeat as nessicary. next, spray whatever paint u want on the model.

I just read a piece about mixing Tamiya Acrylics they stated that you should stir and not shake the paintbottles. And you cannot dilute the paint with water.
Can anybody help me with this.