1) Prepare some stones in advance. If necessary, wash with soap and warm water and dry them. An abrasion of the surfaces to be bonded improves adherence.
2) Mix equal parts of both pastes and knead with your fingers and the palm of your hand for 5-6 minutes, until the color is uniform and the individual colors of the two doughs have completely blended. (Before hardening, the putty, like many other household chemicals, can cause irritation to sensitive skin. In such cases, use gloves of rubber or polyvinyl. When you're finished, wash everything with hot water and soap, even your hands).
3) Form a small ball with the dough and place it in the center of the metal cap.
4) Press the cap on the stone at the point where you want to affix it, so that the dough fills the the cap, the eyelet, and is pressed out of the edge of the cap.
5) By pressing the dough on the edge of the cap with your finger, close the gap between the edge of the cap and the suface of the stone.
6) With a toothpick, clean out all the dough that has filled the eyelet.
7) To obtain a well-polished surface of the edge of the cap, smooth with a wet fingertip.
8) The speed of hardening depends on the temperature at which this process occurs, so that at 20-25 C the dough becomes hard as a rock in a matter of 3-4 hours. While increasing the temperature (e.g. under the hood of a filament lamp), this can be accomplished in minutes. Keep the dough not yet mixed in the refrigerator if a long time elapses until the next use.
9) The stones are ready to use! See also Youtube