We are re-modeling some of the labs at my night job. I went back to see what they have done lately. Well "another mans trash......." as the saying goes. They had thrown away a AC return grille. Brand new-never used. I took it to see if it can be used as a grid. It is 2 foot square, and about 1/2 inch thick, with about 1/2 inch spacings. One down side is it is white. But a quick spray bomb will take care of that.
Don't know how well it will work as a grid. But 'a free grid is better than no grid' as I always say. Ill let you know!

