RE: Whats happened to Monocoat ?
Monokote did make a statement years ago (at least 12 years ago) that, due to environmental hazards/concerns, they removed an adhesive chemical they had been using in their original formula, and began using another adhesive chemical that was environmentaly friendly.
In my opinion, the new formula has changed the performance of Monokote. It no longer stretches as well or as much as it used to, and is a little more difficult to work with. I noticed that it stretches more in one direction than the other. Thus, when used on a wing, both wing halves (and top and bottom) need to be applied lengthwise of the roll of Monokote.
The new Monokote is also more prone to sagging after it has been applied. It doesn't have the same adhesion as it used to.