Limestone is a soft, sedimentary stone made up of calcium. It can contain modest cracks called fissures at or beneath its surface. Over time, normal wear and tear can cause these fissures to open up broader into bigger cracks. If a crack appears in stone, it may detract visually from the rocks, and maybe weaken it also. Filling the crack using epoxy resin tinted to match the shade of the bunker both masks that the crack and gives the stone back its tensile strength.
Vacuum or sweep the crack in the bunker to eliminate any loose stone debris or dust. The crack needs to be totally clean and free of any loose stuff for the repair to hold.
Wipe acetone over the crack with a soft fabric. This cleans the crack and also prepares the surrounding stone to take the epoxy restoration.
Mix up the epoxy resin using the pigments till it matches the color of the stone. Put a few of those mixed epoxy to the syringe.
Inject the epoxy to the crack with the syringe. Begin at the far end and pull the syringe toward yourself as you push the plunger. Fill the crack until it’s level with the surrounding stone. If you overfill the crack, scrape the excess epoxy immediately with a craft stick or razor blade. Allow the repair harden for 24 hours.