Epoxy paint failure in B-52 fuel tanks: Part I—Preliminary development of a model for the process

A small percentage of the protective interior topcoat in B-52 integral wing fuel tanks is failing. Two separate modes of failure are observed. On vertical surfaces, fragments of paint detached from the aluminum contain frozen in wrinkles, striations and channels. On the floor of the fuel tank, paint detached from the aluminum is flat and featureless. In this first communication, the BMS10-39 epoxy paint is structurally characterized, with emphasis on the detection of elements of chemical degradation. A preliminary model is then developed for the delamination process operative on vertical surfaces, as supported by interactions of the coating with diethylene glycol monomethyl ether (DIEGME—a fuel system deicer used in military jet fuel) in high temperature distillates from JP-8 jet fuel; and for the delamination process operative on the floor of the fuel cell based on interactions of the paint with mixtures of water and DIEGME.