I had been having trouble with the lid of my vacuum chamber with the first lid that came with the unit, becoming opaque with cactus juice contact and the second one is a piece of plexiglass but was starting to star fracture out from the vacuum guage hole, so I got a piece of 8mm alloy and cut a smaller window so there was complete support with no starting point for any of the fracture starring to start from. There are still the end points of the fracture visible but with all round support and no intrusion through the plexiglass, they should not continue to develope, but I will get in a fresh piece to have on hand just in case.
