1. Repair

2. WHEN IS REPAIR NECESSARY?
Quality Assurance applies acceptance criteria during in-process inspection, final inspection, and/or field inspection → part may be discrepant (defective) and rejected
Discrepancy report (DR) written

3. QUALITY ASSURANCE/ENGINEERING HAS TO CLASSIFY REPAIR REQUIRED
apply judgment
may be explicitly stated in repair criteria guideline (General Repair Specification)
repair classifications
rework
standard repair
Material Review Board (MRB) - members include Quality Assurance and Engineering

4. EXAMPLE OF GENERAL REPAIR SPECIFICATION
Class IV - cosmetic, negligible repair - rework - non-structural repairs to bring part up to required drawing finish
Class III - minor structural repair - standard repair procedure applicable
Class II - major structural repair - standard repair procedure applicable
Class I - major structural repair - requires MRB review

5. TYPES OF COMPOSITE REPAIRS
bolt on repair
filling
resin/adhesive/syntactic foam/composite
removing/filling
scarf repair (50:1 if possible)

6. REPAIR MATERIALS resins/adhesives syntactic foam/foaming adhesives
viscosity
cure time and temperature
syntactic foam/foaming adhesives
reinforcing fabric, milled fibers
preimpregnated fabric and tape

7. WET SYSTEM ADVANTAGES room temperature cure
can use minimal process materials and equipment

8. PREPREG SYSTEM (HOT BONDERS) ADVANTAGES
resin content control
cleaner system to work with
may provide better match with existing material
Wichitech Composite Repair Systems

9. REPAIR PROCEDURES in general, these four steps are followed
surface preparation
application of material
cure: time, temperature, and pressure
finishing