Welding New PVC to Existing PVC Geomembrane

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New PVC geomembrane can be welded to existing PVC liner that has been buried. Liner welding can be accomplished using a few simple techniques.

  1. Carefully uncover the existing PVC in an area approximately 5’ wide along the edge to be welded. 5’ is needed to work out any wrinkles that may be in the existing liner. Use square-end shovels and avoid puncturing or tearing the liner.

  2. The final removal of the cover can be done with brooms or high pressure air. Water is not recommended unless there is excellent drainage, because it may tend to flow back into the seam area during the liner welding.

  3. The area where seaming is done should then be scrubbed with water. Detergent may be needed to remove any film from the surface of the existing liner.

  4. A pre-wipe is not usually required. Depending on the condition of the existing liner, a pre-wipe of MEK may be necessary. This may however affect final seam strength.

  5. Seaming is accomplished using EPI-20-SOL chemical fusion agent. Clean the area between the two sheets of any sand, dust or water. Apply EPI-20-SOL chemical fusion agent into the overlap area with a squeeze bottle or paint brush to make a 2" wide seam. Be sure to allow the top sheet to be wetted by the chemical fusion agent. Allow 2 to 5 seconds (depending on sheet temperature) for the chemical to react with the PVC surfaces. The material should then be pressed together immediately while the chemical fusion agent is still liquid using cotton rags and a roller.

  6. Pay particular attention to any area that consists of more than one layer of material. Excess chemical fusion agent should be wiped up immediately after the seam is made.


For more information on geomembrane welding, refer to the EPI "Solutions: PVC Welding · EPI-20-SOL Chemical Fusion Agent", or contact EPI at 800-OK-LINER.

For more information, call 800-OK-LINER today!

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