The bag must be one continuous piece of plastic material. There can be no joints or seams in the bag as this will be opportunities for leaks. The bag is considerably larger then the panel so we can make sure pressure will be applied evenly across the whole assembly.
We remove the top backing on the black double sided tape that has been placed on the table surface surrounding the panel. The bag will be attached here. You will notice a bunch of yellow pieces of tape along the edges of the bag. These are pleats that are made to accommodate the oversize of the bagging material and to make sure there are no constricted areas when the vacuum is applied.
You also see a black plastic hose held to the table with a clamp. This hose leads to our vacuum pump and is attached to a perimeter spiral wrap hose that allows air from under the bag to be drawn into the vacuum pump. This spiral wrap hose is inside a fold of the peel ply. We want to avoid resin being drawn into the vacuum hose as much as possible.
Here you can see the black double sided tape goes around the whole panel. Lots of pleats held together with yellow double sided tape and as you can see, the bag is very much larger then the panel. This extra bag material makes sure there are no stressed areas once the vacuum is applied. Stressed areas might allow the panel assembly to shift or may impede the flow of resin when infusing.
Here you can see the whole panel under the bag material. Again, lots of pleats to allow good vacuum and resin flow.
Now the fun starts. Apply some vacuum and check for leaks. On this panel, we had some leaks, possibly from the table joints, not sure but we chased these leaks for two hours until we decided that we had enough vacuum to allow the resin to infuse so lets get at it. You can see the bag is pulled down a bit, not entirely flat yet but getting there. Steve had an acoustic leak checker and although we spotted some leaks quickly, it was another matter to get them to stop.
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