"Within 24hrs, the 242 will melt the plastic"

Yep, right on the the Loctite 242 label it says "MAY ATTACK SOME THERMOPLASTICS".  The only chemical mentioned on the label is methacrylate ester, but if you go to Loctite's website and look up the MSDS (Material Safety Data Sheet) there are several others in 242 that are also considered hazardous.  I'm not sure which one attacks plastic, although methacrylate ester sounds like a good candidate.

Several years ago I had an experience similar to Angier's in which I discovered that anything containing toluene will also attack thermoplastics. I guess the moral of these stories is, read the product label before you use it.

Tom Gourley