I don't have any experience with the stuff, but it seems like more of a strong clear coat than what we need to harden pep models. I can for sure say that this wouldn't be thick enough to absorb into any fiberglass cloth or mat, and it's hard to say if it would even be sufficient for the first layer to harden a pep model. It the stuff is cheap, it wouldnt hurt to test it out on some cardstock! As for the efficiency part of it though, think in terms of spray paint. I guarantee you I go through a lot more spray paint than I would brushing on paint, due to overspray, clearing the nozzle after painting, and the fact that 1/2-2/3 of my paint ends up on my masking tape or the surface my model is sitting on.