Honestly, I hate Modelflex - except for certain touch up brushing applications. Half the jars I ever bought were jelly (freezing in transit to LHS). With the exception of their oxide red or boxcar red, none of them gave a 100% consistent finish. Very, very dependent upon the model or primer finish. Look at it wrong and it's a mass of drips. Look at it another way and it comes out sputtering.
If you're new to Modelflex, you should practice on several test cases with the colors you intend to use!