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A vacuum veneer bag will develop leaks after it has been used and the leaks normally come from three areas. The bag connector, the C Channel Closure and of course the surface of the bag.
The easiest way to check the C Channel is to put water in the lip while the bag is under vacuum. If it leaks, it normally leaks at the outer edges and you will see water running along the inside seam of the bag. The outer C clip can fatigue with time and to stop the leak, apply a spring clamp over the C at the end. The additional pressure from the spring clamp will normally stop the leak.
For the other leaks, line the inside of the bag with newspaper. Seal it and apply vacuum. Turn the bag upside down to check the bag connector. Sponge plenty of water around the connector and the hose. If it’s leaking here, you will see water either running up the hose or it will stain the newspaper.
Leaks in the body of the bag can be caused by a sharp point or edge or by over stretching the bag. This cause’s small pin hole leaks which are difficult to detect. With the veneer bag under vacuum, sponge large amounts of water on the surface until you see the paper stain.Do both the top and bottom side.
Repair with a patch kit from Q.V.P. You can also use a vinyl pool repair kit in a pinch. Vinyl glue will stick to the poly veneer bags as well as the vinyl material. Clean both surfaces with PVC pipe cleaner, apply PVC pipe or vinyl glue and let it tack up for about 5 minutes. Press them together and clamp overnight. The patch should go on the outside of the bag.
For a quick and temporary patch, you can us the plastic tape. Put a piece of tape inside and on the outside of the bag.