Durham's Rock Hard Water Putty is a versatile and durable product that can be used for a variety of repairs, including filling holes, cracks, and imperfections in wood, plaster, and drywall. However, it's important to note that while it can be used to seal small leaks, it may not be the best solution for sealing a leaking corner of a mobile home1. Water putty is not waterproof and can absorb moisture over time, which might not provide a long-term solution for a leak. For sealing leaks in a mobile home, it's generally better to use products specifically designed for that purpose, such as sealants or caulks that are waterproof and can handle the movement and expansion that mobile homes often experience.