I recently purchased a structure kit, but upon opening it, I found the walls were all pretty severlely warped.
Is there a way to use some sort of heat source to flatten them out without worrying about melting or distorting the walls?
Sounds like a challenge. I know it is recommended to use very warm water and weights to straighten out resin castings. If you can’t or don’t want to return the kit, try warming the walls up with hot water from the tap and laying weights on it on a flat surface untill they cool. I have several 1/4" steel bar stock cut about 4" to 5" long that I use for weights.
Try microwaving the warped pieces between two pieces of glass. It’s what I do for warped resin, so it should work for plastic. Just don’t use full power, and don’t nuke 'em for more than a minute, until you figure out the technique.
I have a couple of “bean bags” I use for heating up my arthritic shoulder. I microwave them to heat them up. I then put the plastic piece on a metal cookie sheet with a bean bag under it. I then put another cookie sheet on top of the styrene piece with the other bean bag on top. The bags are heavy enough to apply pressure to flatten the styrene sheets and the heat softens it up just enough without causing any damage. The bags cool fairly quickly but a quick pop into the nuker and they are hot again.