Fiber Reinforced Polymer (FRP) repair systems on pipe substrates have been used successfully for leak sealing and for reinforcement. Due to corrosion mechanical damage or both some small defects such as pinholes cracked welds and small punctures can be repaired by such composite repair systems. The repair method consists of the design of a circumferential composite wrap which is laid-up and bonded to the pipe substrate in the field where a defect exists or is expected to exist. The effectiveness of the composite repair system is highly dependent on the adhesive fracture toughness between the two substrates pipe and composite. The interfacial fracture toughness through the use of small circular defects known as “blisters” has been characterized through the use of the “blister test”. In some cases a repair may not have proper surface preparation in the immediate defect area due to severe corrosion. However proper surface preparation is available in areas slightly removed from the defect. The repair for this type of defect will create a large encapsulated blister. Although large the general shape of the blister and its front can be easily controlled. Therefore it is desirable to optimize the geometry to create a blister front which will result in the greatest performance. This study analyzes one textile glass/epoxy composite repair system manufactured by Neptune Research Inc. This paper presents the results of an investigation including theoretical analysis full-scale experimentation and analysis of results to better understand and design reliable methods to optimize initial blister shape and front geometries.