I've always used black primers for my darker armies, but since I started experimenting with bright lizardmen colors, I bought white primer. I got the gw skull white stuff and it has been cracking when it dries, is this my spray technique, primer quality, or do all white primers crack?
I have never had any of the primers crack, switched over to ArmyPainters cans last year though so not sure if there has been any changes. Though, are you trying to spray paint in a either cold or hot environment? Reason I am asking is due to I assume the paint behave like normal spray paint, which will crack if you try to spray paint something when its too cold or if there is a heat difference between the spray and the object. So it might be that.
GW's white primer is trash. You have to shake the hell out of the can, and then "Swirl" the can. You can pick up Sandable Automotive Primer is white, grey or black. It's 1/4th the price, and works better than the GW stuff. -Matt
It also might be a case of some mold release agent still on the model, this happens occasionally, but it nothing a little soap and water can't fix.
just realize with army painter that you will never get it off plastic if it screws up...I would rather use a 99 cent can from Home depot than a 15 dollar can from a game store that simple green cant remove... if it worked 1st time then god bless, but man i hate that brand...