There are a few different types of sealants that can be used for a leaky pipe, but the best one to use depends on the severity of the leak. For a small leak, a simple epoxy resin can be used. Just apply the resin to the area around the leak and allow it to dry. For a bigger leak, you may need to use a sealant that is specifically made for leaky pipes. These sealants are usually made of silicone or latex and can be found at most hardware stores.