Hi guys,

> Is it just regular epoxy with black pigment?                                                    

No.

Bonding epoxies are usually a high viscosity resin without reactive diluents and usually they are tixotropic (liquid when agitated, solid when left alone, kind of like ketchup). They often are also filled. The hardeners often contain substances which allow variable mixing ratios and adhesion to different surfaces, sometimes lower Tg and make the cured resin kind of tacky. Depends, there are many different epoxies out there.

The skinning epoxy sold by EC seems to contain a component which promotes adhesion to certain surfaces and they are coloured black, otherwise it seems to be more or less standard low viscosity laminating epoxy. At least that's how I interpret the MSDS.