Yipe!
Well, I've only bounced a model off the wall once, but that wasn't a "whoops". It was quite intentional! LMAO
My biggest "whoops" was when I was about 13 or 14. I was still using evil water-based and acrylic paints at this time, and the Tamiya Acrylics had just come out.
I brush-painted my Monogram 1/48 P-47D Bubbletop in the RAF far-East scheme (I was still afraid of the airbrush at the time! LOL) and it looked groovy. I had also brushed on gloss for the decals, and needed to put on a flat clear.
Well, seeing as I had used Tamiya's new acrylics for the scheme, I decided to use their flat-clear as well. I put it on and left the dungeon only to come back the next day and find that the modeling gods had really intended for me to put a winter camo scheme on this particular Jug, 'cuz the whole thing had turned WHITE!
It was after this that I discovered that Tamiya's Flat Clear was not a "clear" at all, but a Flat Base to be mixed with gloss colors! (After all, that's what it said on the jar, but who am I to pay attention to such trivialities? LMAO)
So that's my biggest modeling "whoops", next to the time I melted a scratchbuilt P-40 cockpit with too heavy an enamel wash, but that's another tale...
Fade to Black...