What could this adhesive be? Undermounted sink.

[i&e JOHN]

It's really ROCK HARD in its cured state, glossy, black, seems very good, would love to buy more to glue more stuff at home. As mentioned in an old thread here about undermounting a sink, it seems countertop manufacturers are secretive about what products they use. We've just had this laminate countertop with an undermounted sink delivered from DFI-Geisler (who have a policy of not even responding to inquiries from private individuals/end customers), and the sink is glued with this black glue that is reportedly epoxy but what kind? TEC7 is used extensively here at home but this seems better, harder!

 

[InsidersUnited]

Looks a bit like some hot glue?

 

[Torsten Er]

It is really HARD AS A ROCK in its cured state, shiny, black, seems very good, I would love to buy more to glue more things at home. As mentioned in an old thread here regarding under-mounting of sinks, the countertop manufacturers seem secretive about what products they use. We have just had this laminate countertop with an under-mounted sink delivered from DFI-Geisler (which has a rule not to even answer inquiries from private individuals/end customers), and the sink is glued with this black glue which is said to be epoxy but what? TEC7 is used extensively here at home, but this seems better, harder!

Looks a bit strange, but isn't it boat glue? I know it's used frequently for this type of work.