A hailstorm on the roof of my tonner panel instantly convinced me to buy vast quantities of sound deadening. I was, quite literally, driving a fifteen foot long kettle drum for an eight-minute jazz solo. My cheapo alternative to Dynamat was Peel'n'Seal wall insulation, found on sale at the home improvement mega-mart. It's thinner, non-aerated rubberized asphalt sheets; still foil backed for thermal insulation and instantly adhesive to any surface. It doesn't silence the interior like Dynamat can, but it stops the giant kettle drum effect. As an added bonus it stops the windowless steel tube from becoming a sauna/pizza oven.
I packed the barn door cavities with closed-cell expanding foam to see how it would work, no roll-up windows to work around back there. I don't recommend it, not because it's ineffective as a sound/heat insulator... it's brilliant at that. I don't even mind that it increased the weight of each door by over ten pounds. The problem is permanence; I have moisture accumulating inside the door below the foam and cancer is starting to bubble the paint again. Imagine that, just fifteen years parked under a tree and my brushed-on Rustoleum paintjob is failing. I'll need to dissolve the foam with a solvent to get to the rust.
I found a 100% polyester comforter and jammed it into the gap between the roof struts and skin. That may be a good direction for the space between body panels, it won't mold or rot if it gets damp. And you can just yank it out and clean the cavities, no solvent required.
Last edited by Hedgehog; 06/03/2017 3:30 AM.
