Technical data

13773-001
51-20
Page 1
COMPOSITE REPAIR
1. DESCRIPTION
The quality of all repairs is directly related to application of proper repair procedures. This includes: clean-
ing and preparing the damaged area, cutting reinforcements, mixing and applying resin and curing the
repair.
The following are general practices used during most composite repairs. A repair technician must be famil-
iar with these practices prior to attempting composite repairs on this airplane.
2. MAINTENANCE PRACTICES - GENERAL
A. Resin Mixing
WARNING:
Use only approved resin systems for repair. Never substitute another resin
system. Resin must be mixed in accordance with the procedures described
herein. Always follow the manufactures recommendations.
CAUTION: MGS L418/418 resin system will not cure at room temperature to a condition suit-
able for handling or processing in any manner. At room temperatures this resin
system will only reach an early stage of cure and will be very brittle and easy to
irreparably damage. Never bend, twist, pull, or push repair area prior to initial
cure.
High ambient temperatures will decrease worklife and viscosity. High ambient
temperatures are acceptable, but will shorten application time. An increase of
18°F or 10.0°C will decrease the application time by 50%. High humidity (above
65% relative humidity), accelerates reaction and shortens application time.
(1) Acquire necessary tools, equipment, and supplies.
(2) Zero scale, to assure accurate measurements.
(3) Place mixing cup on scale and record mixing cup weight (MCW).
(4) Pour required amount of base resin into mixing cup.
(5) Place mixing cup with base resin on scale and record the total weight.
(6) Subtract mixing cup weight from total weight (mixing cup and resin), to determine the base resin
weight (BRW).
(7) Record the base resin weight.
Description P/N or Spec. Supplier Purpose
Resin (structural repair) MGS L418/418 MGS Laminate repair
plies
Mixing container (cup) - Any Source Mix resin system
Stir sticks - Any Source Mix resin system
Scale 18605T84 McMaster-Carr Weigh chemicals
30 Nov 2000