Vacuum bagging parts with the Space bag has been a mixed scene so far. It is a wonderful concept, but the bags have been failing. I started with the 3’ x 4’ jumbo bags. I am bagging the dome triangles for the lunar lander top. They are ply/core/ply sandwich parts. Recall that the spacebags let me run the vacuum for only a few minutes, not the usual 6 to 10 hours. The first jumbo bag kept the vacuum for 3 days until it failed. The second jumbo lasted an hour and the third was good for about 10 minutes. A smaller XXL bag lasted 2 days, but as in this picture, on a second attempt, the bag would not hold a vacuum. I tested the closable seams and they were fine.
I spoke to SpaceBag and they will send replacement bags. They did say the bags should be airtight when you get them and good for several uses with no problems. I guess I will need to fill up the bathtub to see where the leaks are. I will do a dry run on every bag in the future to test it first. Notice the duct tape on the sharp edges to protect the bag.