Iron Man, Vol. 1 #92 (1976)

Burn, Hero--Burn!
Krissy Longfellow and Abe Klein are returning from a meeting with lawyers. One of Stark's competitors somehow has a patent on one of his designs that predates his own patent by two months. On that return trip, the army convoy they are following is attacked by the Melter. Iron Man soon arrives, but the Melter fuses his armour and Iron Man ends up immobilized in the river. Realizing that abandoning the armour is his only chance to survive, Tony does exactly that. In his second showdown with the Melter, he sends a robotized version of his original armour after the Melter first, and uses that to distract him long enough to sneak up behind the villain and ruin his melting ray. Convinced he's seen a ghost, the Melter screams incoherently as he accidentally falls out of his lighthouse and into the ocean below.
Release Date: 1976