Hi @Plum,
A warm welcome to the Bunnings Workshop community and thank you for your question.
As it is not a typical application, there is not a specific system for this purpose. Australian Panels, the producers of YellowTongue have provided information here on how to paint YellowTongue when used as a wall lining, but not as flooring. I imagine a similar approach will work, but as it will be walked on, the wear will likely be increased.
I can recommend products and a method, but there is no guarantee that they will last as long as they would in their normal applications.
As YellowTongue is resin-enriched, you will have to buff up the surface to create a key for your primer and paint to stick to. Sand the surface with 120 Grit sandpaper to remove any dirt or contaminants and to buff the surface. Once sanded, vacuum the surface to remove all sawdust and particles from the surface.
Once prepared, apply a coat of Dulux 1L PRECISION White Maximum Strength Adhesion Primer to the entire surface and allow it to dry for an hour.
When your primer has dried for an hour, you can apply 2-3 coats of Feast Watson 4L Satin White Timber Floor Paint.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
