Adding an outdoor pond is a relatively inexpensive and simple way to add interest and beauty to your landscape. Pond liners, linings typically made of rubber, allow ponds to retain their shape by preventing water from absorbing into the ground. You can join two pond liners together to create a larger, more striking water feature to accent your landscape. Follow these steps to learn how to join pool liners.
Lay out the two pieces of pond liner you intend to join together. Overlap the two liner pieces at the edges by at least 7 inches. Draw a line with a piece of chalk on the bottom pond liner along the edge. Then, fold back the top pond liner from the bottom liner by 7 inches.
Apply primer, according to the manufacturer's instructions, to the bottom pond liner. Use the chalk line you previously drew across the bottom liner to guide you as to where to apply the primer. Apply primer over the section of the top liner you previously folded back. Allow the primer to fully dry.
Position a roll of seam tape, with the paperbacked side of the seam tape facing you, at top end of the bottom pond liner. Roll out tape from the tape roll slowly across the liner, maintaining approximately 2 inches of separation between the pond liner's chalk line and the tape's edge.
Apply a bead of sealant along the bottom pond liner. Leave approximately 1 inch of a gap between the sealant tape and the chalk line. Peal the paper backing off the applied seam tape and fold the top pond liner back over the tape.
Use the roller to apply pressure across the top of the top liner. The pressure will allow the joined pond liners to adhere to each other.
If the edge of the top liner remains loose, apply a bead of sealant to the top liner edge to better secure it to the bottom liner.
Always wear safety gloves when working with glue or other adhesives or chemicals.