NOTE: Do not use toluene near open
flame, heat, or electrical sparks. Avoid
prolonged contact with the skin or
breathing the fumes. Use toluene only in
well ventilated areas.
Do not touch the cleaned raft areas when
handling. Clean both the pieces to be cemented
with four applications of toluene. Apply the
toluene with back-and-forth strokes on the first
and third applications and one-waystrokes on the
second and fourth. Allow the areas to dry between
Prepare cement and accelerator mixture.
Prepare only enough mixture to last for 8 hours,
as this is the effective active period for the
mixture. Dispose of any remaining mixture after
Using a disposable brush, apply cement to
completely cover surfaces to be cemented.
Apply two coats of cement to both pieces,
allowing the first coat to dry for approximately
When the second coat of cement becomes
tacky, place the pieces together. If the cemented
area is a cut or tear, butt the edges of the damaged
area before applying a patch. Roll out the bubbles
using a wooden roller.
Allow the cemented area to dry for at least
48 hours, and then dust the area with talcum
If the seam tape is only damaged, trim the old
tape and replace it with new tape. Overlap the
other seam tape a minimum of 1 inch. All tapes
and patches are applied to the life raft without
tension. The tape is applied in such away that
an equal amount of tape width is on each side of
the seam edge, which it covers.
To patch a damaged area on a life raft, select
the applicable color and type of raft cloth,
depending on the type of raft to be repaired. Cut
a rounded patch 1 inch larger than the damaged
area on all sides. Scallop the edges of the patch
if it is larger than 5 inches in diameter.
If the damaged area in the floor is larger than
1 inch, patches must be applied to both sides.
Intermediate maintenance activities have the
prerogative to declare rafts beyond the capability
of maintenance if internal patching is required.
Center the patch over the damaged area and
trace an outline of the patch on the raft fabric.
Cement the patch to the damaged area in
accordance with the instructions previously
discussed in this section. After all repairs
have been made, perform a leakage test on the
raft and dust the repaired area with talcum
The flotation tube is separated into two
compartments by internal vertical bulkheads.
Bulkheads are constructed of laminated cloth and
are of a six-gore hemispherical design. The
bulkheads are installed amidships, equidistant
from the bow and stern so that the volume of the
two compartments is equal. A 4-inch-diameter
patch of laminated cloth is securely cemented to
each side of the bulkhead, at the manifold, to
protect the bulkhead against abrasion by the
manifold diffusers when the raft is packed in the
An inflatable seat is installed in certain
multiplace life rafts; for example, the LRU-12/A,
LRU-13/A, and LRU-14 series. These seats are
circular and are made of laminated cloth. The
ends of the seat are tailored to fit the curvature
of the flotation tube. The inflatable seat is an
independent air chamber and is manually inflated
through the topping-off valve by using the hand
pump provided. It is attached to the bottom of
the raft with Y-shaped hinge tapes made of
laminated cloth. This method of attachment
allows for expansion and prevents undue stresses
between the bottom of the raft and the seat.
Each LRU-12/A, LRU-13/A, and LRU-14
series life raft contains a supply pocket that
measures approximately 8 x 8 x 2 inches. The
pocket is attached to the starboard side of the
flotation tube surface inside the raft by stitching
the pocket to a patch and cementing the patch to