I used this on a concrete bird bath. It dried/cured for 72 hours but upon exposure to water broke within an hour and had the consistency of wet clay or caulk. What did I do wrong there?

Thank you for posting your inquiry on DAP Ready Mixed Concrete Patch. DAP Ready Mixed Concrete Patch is designed, tested, marketed, labeled, and recommended for patching small holes, cracks, and other minor cosmetic defects in masonry surfaces. The application that you describe would not be considered appropriate for this product, as it is not formulated to be submerged under water. Should you have any questions or require further assistance, please feel free to contact DAP’s Technical Customer Service Department at 888-327-8477.