Having established a need to close ventilation grilles in the event of an engine bay fire, we immediately discovered that bodybuilders required their own individual solutions, and were presented with a real challenge from one of them in the form of a mesh box grille application (13mm Square apertures). A solution was developed that allowed the grille to be painted into (Any RAL Colour, See Above Picture) which would close in approximately 1 minute denying the fire an escape route to the outside of the vehicle. The paint thickness has been measured at 125 microns, which is comparable with standard paint practices, allowing maximum airflow, without restriction through the grille itself.
See how the grille reacts and closes to fire: