Keyframe

Is there a way of placing a keyframe without it automatically joining the previous keyframe. Im trying to place a keyframe then have a gap, then place another one, so that the image appears and disappears continually. Im going this with multiple layers to get that effect whereby you have animation that moves constantly around the outline as it is redrawn.

When I add a new keyframe further along the grid, it joins up the previous keyframe and means that the image is present in between. I have to delete the frame inbetween manually each time which is reeeeally time consuming. I was hoping I could just highlight all the keyframes and keep repeating them. They all end up joining up so you see all layers.

RR