Thank you for posting your review. We're sorry to hear about your experience with DAP Plastic Wood All-Purpose Latex Wood Filler. Plastic Wood is not designed or recommended for use as a "stand alone" product, as indicated on the product package label and supporting product literature: "Exterior applications must be coated with latex or oil-based paint or solid color stain”. The only way that the product would behave as described, is if there was moisture exposure. This means that water is entering the patch through the paint or bypassing it (from the edges or from underneath). For applications where moisture is a concern, we would recommend the use of DAP Platinum Patch Advanced Exterior Filler. Unlike other wood patches and spackling compounds, this formula is designed for stand-alone performance. Should you require further assistance, please feel free to reach out to DAP’s Technical Customer Service Department at 888-327-8477.