Make a cutout in the cardboard sheet which is slightly smaller than the edges of the clock faces with the utility knife. Cut the cardboard down to cover the base of the projector. Place the fan facing the projection area in front of the projector to increase air flow as well as to more continuously agitate the oil and water combination.
Using the oil-based candy dye (sparingly to prevent too much opacity), dye the clear mineral oil. Store in the eyedroppers for use during the light show.
Cover the projector with the prepared cardboard and turn the projector on. Place the larger clock face in the cutout area making sure the edges fall outside of the cutout shape.
Pour a small amount of water into the larger clock face and then add the food coloring of your choice. Turn on the projector, and dimmer if you have one.
Add a few drops to the larger clock face . Do a little at a time.
Using the smaller clock face, gently lower and raise its surface to the oil and water mixture in the larger face causing the oil and water mixture to swirl and move. Don't drop the smaller clock face in.