[neoxul]

I have asked before for painting over black plastic and make some try on a runner from a model kit (pla-act 03 : oda) on a black runner.
I tried to sand a bit, either it need to be sanded for a quite a long time but the yellow I tried didn't seem to apply that well even after that. To be true, it would need perhaps 3 or 4 layers to may be look acceptable (but not even sure really)
I am still thinking about getting a primer but I am lost on what I should take (HLJ has a water primer either white or grey available) but I don't know for sure if will compatible with the gundam marker applied by brush.

On another hand I wonder if the parts has to be washed when you want to apply a gundam marker I think I read everything about it, what do you recommend ?

Thanks in advance for any help on my problems