PS-28 Cruiser
PS-28N Cruiser
CR-MM-1-0-00
CHAPTER 15 – AIRPLANE REPAIRS
Revision No.: -
Date of issue: 2011-03-08
15 - 12
Manufacturer,
name
Type
Mixing
ratio
Delay
Rate of
setting
Time of
setting
Temperature
Fillers
MGS,
A: L285
B: Hardener
285
epoxy
A:B
100:40
to be
processed
within 50
min (for
0.2 kg
(
0.44lb
s)
mixture)
40%
16 FH
(32 FH)
20-35°C
68-95°F
(17-20°C)
(62-68°F)
thickening:
Aerosil,
microballs
100%
26 FH
(72 FH)
(2 FH)
20-35°C
68-95°F
(17-20°C)
(62-68°F)
(80°C)
(176°F)
Tab. 15-3:
Recommended materials for mixture preparation for application of leveling layer
Sanding
Sanding or eventually sealing the surface is made after setting the mixture and possible
tearing of the used polyethylene. It is suitable to start sanding with grain size up to 160 and
finish with grain size of at least 400. It is carried out by dry sanding equipment with suction
from the sanding area. Al
2
O
3
or equivalent (fused corundum) can be used as sanding
material. Basic material of the part must not be diminished at sanding.
NOTE:
Especially in case of C/K (carbon/Kevlar) stiffener in the basic part, sanding
through up to the stiffener must not occur (complication - see note about
preparatory sanding at medium damage).
Finishing
See section 15.6 - Paint repairs
15.5.3.2
Medium damage
Repair of damage by replacing the stiffener part, by mastic and varnish repair. At such repair
it is necessary to distinguish type of used stiffener (especially for sanding):
•
C/K (carbon/Kevlar), roving of fabric of black color (C) take turns with yellowish (K)
•
G (glass), rovings from milky white to transparent
Preparatory sanding
For good adhesion of repair layers it is necessary to do sanding up to the depth of damage.
It is necessary to do surface sanding from the damage area with overrun at the least 25 mm
(
1 in
) for every damaged stiffener layer smoothly up to the top layer and then about 51 mm
(
2 in
) for finishing and mastic application. It is convenient to do sanding with sanding
material having grain size of 160. It is carried out by dry sanding equipment with suction
from sanding area. Al
2
O
3
or equivalent (fused corundum) can be used as sanding material.
NOTE:
In case of C/K stiffener K roving tend to rise up from the surface at sanding -
it is difficult to sand them, we recommend using diamond sanding tool and
one-way sanding.
Dust removing
Dust is removed by wiping with a clean and dry brush or by a vacuum cleaner.
