Surface Primer is available in a range of basic shades most frequently employed to prepare the surface of the model or miniature before starting the painting process. Primers can be applied on all surfaces, resin, PVC, brass, white metal or wood. The primer preserving even the smallest detail of a model, and improves the adherence of the colors applied on this base. It is recommended to apply the Primer in various layers; the product dries rapidly and forms a homogenous film of extraordinary strength and resistance within a few hours after application. Surface Primer can be used directly or diluted with Vallejo Airbrush Thinner of Flow Improver. The recommended compressor settings are around 15-20 PSI or 0.5 to 1 kg. For best maintenance of the airbrush, it is recommended to use the Vallej.
I put this through an airbrush for priming mini's and I'm always very satisfied with the result, can easily control the thickness of layers.
It's also great for hand brushing on with some projects but can flood some details on smaller miniatures if you hand-brush, and when I have tried thinning it with water i found that it would disrupt the primer and cause it to rub off easily, I don't think this would happen with an appropriate with medium but that's my experience with water at least.