Painting acrylic over enamel - Mistake?

[Wiking]

Hello all, I'm new to airbrushing, and new to Vallejo acrylics (I have spent the past 30 years brush-painting Polly-S, now Model Master Acrylics on 1/72 scale aircraft).

Did I just make a mistake airbrushing Vallejo Acrylic (Air), over Testors flat enamel? - The failure being that the Vallejo is being lifted off the Testors enamel, by the Testors masking tape I'm using.

The Story So Far:
The model is Revell's 1/32 Ju-88A-1, in grey plastic. After masking the canopies and degreasing the plastic, wearing nitrile gloves, ready for painting the whole aircraft, I decided to give it a first coat of grey to give me a even color to the whole model (in other words - the canopy areas are clear, with RLM Grau showing through - painted on the backside - making them darker than the surrounding gray plastic, and I didn't want this darker RLM Grau color to show through the Vallero paint I'd be using on the model).

The best match to the model's grey plastic was a spray can of Testors Lt.Gull flat enamel I had handy, and I sprayed it on in two light coats. That was 48 hours ago. This morning I began applying the German colors using Vallejo Acrylic (Air), and I happily and successfully airbrushed the Hellbllau on the bottom, in two light coats, waiting maybe an hour between coats - that was 8 hours ago...

With the full underside airbrushed with Vallejo Acry Hellblaul, I began masking the edge with Testor's masking tape, "low tack", to get ready to airbrush the topside with Grün (70).
When I tested the adhesion of the masking tape, it pulled about 60% of the Vallero Hellblau off the Testors Lt.Gull flat enamel.

Ugh!

I can think of some options:
- Wait til tomorrow morning, in case the Vallejo needs to be bone dry for better adhesion.
- Experiment with the tape - try a different kind, or abuse the adhesive to create and even lower 'tack' before using it.
- Switch from masking and airbrushing the Vallero, in favor of my usual forte: Hair Stick. Brush paint the topside with ModelMaster Acrylics without masking.. (but that splinter camo on a 1/32 will be hell).

Thanks for any suggestions.... I am enjoying learning to airbrush, but I'm also learning as I go.
Cheers,
- Art

 

[Wiking]

..another option would be "Damn The Torpedoes" and just proceed with masking and airbrushing the large fields of upper Grün and Schwartzgrün splinter camo, then touch up the edges with a brush afterwards... I'll experiment with other tapes first though, and if successful, just go very light on the paint coats.

 

[Crimea_River]

It should never be an issue to paint acrylics over enamels. Though I've never used the Vallejo acrylics, I've heard many complain about their adhesion abilities in general. I have also not used Testors masking tape but even with Tamiya's tape, I "detack" it by applying it to the palm of my had a couple of times before putting it onto a painted surface.

 

[Wiking]

Thank you for offering that background on Vallejo, and the validation on tape tackiness.. I'll start by de-tacking a few different tape types and see what works better...

I'm otherwise pleased with my first foray into airbrushing, and plan to keep using it.

Cheers,
- Art

 

[Wurger]

IMHO the problem is the Testors/ModelMaster enamel. Contrary to the Humbrol enamels the Testors/MM coat looks fattily. The Humbrols always give a matt finish that looks much better and not too fattily . I think it is because of the enamel oil medium. Humbrols seem to have it less or just lighter than the Testors ones. But I agree with CR on the Vallejo adhesion. The colours like peeling off even if the dedicated primer had been used there.

 

[Wiking]

Thanks for the confirmation - and yeah, I can agree the finish of the Testors enamel has a quality that could be described as fatty, soft, oilish.. something like that.
I am having success de-tacking standard household 3M masking tape. The slight downside is some slight lifting at inside corners, for which I hope to compensate by careful attention to the nozzle orientation of the airbrush and by not applying a light coat, several times.
Cheers.
- Art

 

[Wurger]