I understand how strong the atmosphere is, but consistent pressure doesn't necessarily mean rapid acceleration. I can perfectly understand how vacuum could break the lid. But the acceleration required to bounce those pieces down and scatter them around a workshop? I can't visualise it. 

Pressure multiplied by area results in force. Force (without an opposing force (lid failure)) divided through mass results in acceleration. Considering that the lid endures aboutique 7000N (700kg) and weights about 2kg this means acceleration peaks around 3500m/s^2 wich ich around 350 times gravitational acceleration! Obviously only at the very first moment. But this shows that vacuum contains a lot of energy, and that save equipment should be used.

I was wondering why you need such an immense resin trap. Even if I am infusing a whole seven-style hood, wich is basically a third of the whole car, there are only a few drops, if any. I use the ec resin trap more as a safety device for my pump. I have to say that I am always degassing the resin, so there are no airbubbles I need to let through the resin trap. But even if I did, the 400ml seem like plenty of volume for the task. I mean, this are 400g resin for nothing.