I'm so used to using my HDPE brew buckets for beer ferments, that when one of my prized "Big Mouth Bubblers" came empty of wine, I decided to do a cornflake mash in one. Without even thinking about it I poured 2l of boiled cornflakes into it and regretted it within 10secs. It literally started to crumple and collapse from the base.
I had to quickly spray with cold water and pull it up as straight as possible.
It's still usable but badly misformed. I'm very, very pissed at myself.