Engineering validation was necessary for manufacturing concepts intended to facilitate streamlining of aircraft sealing processes.
The objective of this study was to determine if production cycle times can be shortened for aircraft sealing processes. One of the process timesaving concepts considered in this testing was to omit adhesion promoting or to convert this surface preparation requirement into an option.
A variety of sealant bond surfaces (or substrates) were used in this study to test this concept for operations pertaining to fuel tank structure sealing and general (or environmental and pressure) sealing.
Engineering test results presented in this report are the basis of conclusions and recommendations that indicate whether or not specific process timesaving concepts are valid.
The most significant Engineering conclusion was that application of adhesion promoter should continue as an Engineering requirement during surface preparation for sealing of aircraft fuel tank and body (environmental and pressure) structures. Engineering validated two other process streamlining concepts - single brushcoating (SBC) of fasteners, instead of double brushcoating (DBC), and fillet sealing with Class B sealant (no precoating with Class A material).