C I R R U S
A I R P L A N E M A I N T E N A N C E M A N U A L
M O D E L S R 2 0
51-20
Page 23
All
EFFECTIVITY:
(4)
Filler Paste Application
Filler paste may be used to fill dents, gouges, or other voids left in the core or laminate material
after surface preparation. It may also be used for bonding replacement foam core sections and
expanded metal mesh.
For structural composite sandwich repairs, because MGS L418 and L285-based filler paste uses
the same base resin as the structural adhesive, MGS L418 and L285-based filler paste may be
used without curing the repair surface prior to lamination as would be required if using the Epon
862-based filler paste.
(a)
Acquire necessary tools, equipment, and supplies.
(b)
Prepare repair surface as necessary.
(c)
Mix filler paste.
(d)
Using a clean spatula or wooden applicator, fill indentation with paste. Paste should be
approximately flush with surrounding core.
(5)
Backing Plate Installation
Backing plates installed to the underside of the repair area must be manufactured on a surface
with a similar shape to the damaged area. The backing plate shall be approximately 1.0 inch (2.5
cm) larger than the diameter of the hole it is bridging.
If the underside of puncture is not accessible, the backing plate must be installed on the topside
of the puncture. This is accomplished by sanding the repair area and backing plate to a matched
taper to form a scarf joint with a maximum overlap of 0.25 inch (0.64 cm) on the topside of the
puncture.
(a)
Acquire necessary tools, equipment, and supplies.
(b)
Sand installation area according to backing plate location and trim:
Description
P/N or Spec.
Supplier
Purpose
Wooden or Plastic Spatula -
Any Source
Apply filler paste.
Description
P/N or Spec.
Supplier
Purpose
Vacuum
-
Any Source
Cleaning.
Paint Brush
-
Any Source
Cleaning.
Permanent Marker
(Refer to 51-30) (Refer to 51-
Depth tracer.
Sanding Pad
-
Any Source
Abrasion.
Aluminum Oxide Paper
(hand sanding)
60 to 80 grade Any Source
Abrasion.
Orbital Sander
-
Any Source
Abrasion.
Aluminum Oxide Paper
(orbital sander)
120 to 180
grade
Any Source
Abrasion.
5 Minute Epoxy
(Refer to 51-30) (Refer to 51-
Backing plate installation.
Clecos or Small Screws
-
Any Source
Backing plate installation.
15 Dec 2014