It was going to be a simple build.
A couple of months ago, I picked up Timeslip's Ranger 3 kit, intent on making it the Season2 variant of Buck Rogers' shuttle. (Since the studio model had no cockpit, the sealed up windows in George's kit was perfect.) I proceeded to lop off the mount for the tail and start sanding the tail fillet, but was a bit worried about sanding through some of the thin spots as a result of the rotocast nature of the kit.
So, after careful consideration, I decided to fill it with A+B Urethane foam (the kind that expands - similar to the stuff you get in a can at Home Depot for your insulation). Unfortunately, even though I have 40 years of model making experience, I only spent about 40 seconds thinking it through. I mixed up too much and poured it all in at once. I can't remember how long it took me to think, "Uh oh....." - but I think it was pretty much straight away.
I thought I might get away with it. The leftover foam in the cup was starting to harden.
Then the creaking started. Really sweet sound. Until you realize that your $200 model is making it.
Then there was the pop. Not like a balloon, not like a paper bag. More like a tub of Pillsbury Crescent Rolls popping open after you hit them on the edge of the counter. Except that Pillsbury Crescent Rolls aren't a $200 resin kit........
The irony is - it didn't split along the "weak" point I thought was there. It probably would have been fine if I had LEFT IT ALONE!!
So, there you go folks - the "I-wonder-what-would-happen-if-we-filled-this-thing-with-TOO-much-expanding-foam" question is now answered.
Glad to be of service.....