As a rule, foils are glued. Welding is a possibility, but it is a lot of work and can hardly be done by yourself.
- Gluing PVC pond liner - this is how it works
- Lay pond liner without creases - this is how it works
- Gluing EPDM pond liner - this is how it works
Welding before laying
Pond liners are usually already sealed by the manufacturer. Therefore, an exact already for ordering pond plan with all the depth data and cross dimensions necessary so that the film can be produced in exactly the right dimensions.
The manufacturer then welds the strips together to form a complete film. Industrial welding methods are used for this, which you cannot use yourself. This is the only way to guarantee a high level of seam tightness.
Welding for repair
As an alternative to gluing in the event of damage, welding processes could possibly be used, even if this is not common. When welding, it is important to work very carefully and absolutely professionally.
Only PVC foils can be welded, other types of foil cannot be welded. For a clean and tight connection you will have to work with so-called solvent welding agents.
Important when welding
- You are only allowed to weld when the outside temperature is high enough
- the film must be absolutely clean and completely dry
- You should only weld foils that are not too worn or decomposed (PVC often changes after a few years in the pond, the decrease in plasticizers makes the foil brittle and often leaks)
- Heat sources (smoking, open fire, etc.) must be avoided when welding
- It is essential that you allow the solvent welding agent to dry sufficiently according to the manufacturer's instructions, otherwise the tightness of the connection cannot be guaranteed
- Welded points must always be weighted down under pressure so that the connection is later tight.
A tip is to simply dissolve pieces of the foil in solvent welding agent, especially when repairs, and then use this solution for sealing. This makes for an even better seal. Make sure that solvent welding agents are very aggressive and should not come into contact with eyes or skin.
EPDM sheeting in the pond can be repaired much easier simply by using liquid sheeting. Even with PVC foils, you should glue rather than weld - the only exception: if you want to make your pond lining yourself from individual sheets.