Primer variability or just the user?

[Flip]

To date, I have used the Alclad II Primer/Microfiller products (white, grey and black).
I have a H&S Evolution CR Plus airbrush and have been applying the white and grey at 15psi (normally using the 0.2mm needle)
I tried to spray the black with the same settings - nothing
I then cranked the pressure up to 20psi
It sprayed beautifully and gave a nice smooth finish
Problem is trying to put enamel paint on top of the black.
The attached image is the nose cone of the AiP Thunderbird 2 with Humbrol enamel No.105 (Matt Marine Green)
It was a devil's own job trying to coat that and it still looks patchy.

Anyone have any ideas or is it simply a user problem?
Regards,
John

 

[Ian M]

I use Black primer a lot and have not issue. Quite like it actually.

Two things to consider. Have you shaken it to death, then stirred it some more?
If the finish is good but having issue painting it, maybe the paint is just a touch to thin?

 

[Flip]

Ian,
Hmm. I always shake the living daylights out of it, every time before loading the pipette to add to the AB. You can hear the beads rattling in the bottle and I make sure that I can't see any solids at the bottom of the jar. But I must confess that I have never stirred any of the Alclad bottles.
Time to change
Thanks
John

 

[stillp]

Isn't your problem with the Humbrol rather than with the primer? Did you give the enamel a really good shake/stir?
Pete

 

[Flip]

Isn't your problem with the Humbrol rather than with the primer? Did you give the enamel a really good shake/stir?
Pete

Definitely gave it a real good stir,
transferred to a Tamiya mixing jar,
thinned 1:1 with Humbrol Enamel Thinners,
real good stir in the jar
repeatedly drew mixture into a pipette and skooshed back into the jar
(skoosh is Scots for 'transfer liquid at pressure to facilitate mixing' but is quicker to say )
transferred a modicum of the mixture into the AB cup using said pipette (without skooshing)

It's beginning to seem that the issue is neither the primer nor the Humbrol paint but rather the muppet controlling the airbrush (by perhaps over-thinning)
I'll have to experiment further on some plastic spoons.

Regards,
John