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 TM 55-1905-221-14-3
6-16
PROPELLER, PROPELLER SHAFT, AND STUFFING BOX (Continued)
LOCATION/ITEM
ACTION
REMARKS
REPAIR (Cont)
preheat temperature should be
between 600 and 826 (316
F
F
C
and 427 ). In an emergency,
C
a temperature of 400 (204 )
F
C
can be used. An approved rod
of 1/4-, 5/16- or 3/8-inch
diameter should be used,
especially on propeller
sections over 3/8 inch thick.
Smaller diameters, 5/32 inch
and 3/16 inch, should not be
used unless absolutely neces-
sary, and then only when
considerable preheating has
been done. With sufficient
preheat, lower values of the
current ranges recommended by
the electrode manufacturer can
be used. Although lower
currents are desirable, the
operator's skill and experience
must be considered. Therefore,
higher currents are preferable
to currents too low. Higher
currents risk fine porosity in
the weld metal, but currents
too low risk poor fusion and
slag inclusions.
1. Hot-Flow Process. The hot-flow
process provides a satisfactory
method for major repairs.
This process consists of
flowing molten metal of
approximately the same chemical
composition as the base metal
into the joint. This flow
washes away and replaces the
parent metal and forms a
continuous member upon solidi-
fication. Foundry and mold
equipment is necessary for the
use of this process.
6-181
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