Uh, I hang drywall on the side and (unless there's some new high teck sheetrock out there - which I doubt) there is no such thing as "bonding fibers" in standard drywall or drywall mud (spackle is for plaster). Now, the paper backing is full of "fibers" but can't see where that would be a problem.

In a lifetime, the average driver will honk 15,250 times. My wife figures I'm due to die any day now...