(4) Apply one coat of 3918 cement to third (largest)
patch. Apply cement to corded side of patch. Apply one coat
of cement to the second patch. Allow cement to dry and place
smooth patch on the third patch; center the smaller patch on
the large patch. Roll and stitch the cemented patches
(5) Refer to figure 5-12 and complete patch assembly
as follows: Apply one coat of 3918 cement to the remaining
side of the second patch and one coat to the first (small) patch.
Allow cement to dry and center first patch on second patch.
Roll and stitch the small patch thoroughly.
(6) Apply two coats of 3918 cement to the cleaned area
around break on drum (fig. 5-13). Allow cement to dry
(7) Apply one coat of 3918 to the patch assembly; apply
the cement to the underside (containing the small patch) and
allow to dry.
(8) Refer to figure 5-14 and position patch assembly over
break areas. Roll and stitch thoroughly.
(9) Apply one coat of 3918 cement to the outside edge
of the patch and allow to dry.
b. Interior Patch (Fuel Drums).
(1) Clean damaged area of all contaminants and foreign
matter and wash with detergent solution.
Do not buff through nylon barrier
(2) Buff drum wall 5 inches (12.7 cm) in all directions
around break; remove dust and rewash with MEK (Methyl-
(3) Prepare patch assembly as follows:
(a) Cut a patch from 42171 stock large enough to extend
3 inches (8 cm) beyond break in all directions.
(b) Cut a second patch from 42171 stock 1/2 inch (1.3
cm) larger, in all directions, than the first patch.
(c) Cut a third patch from 42114 stock 1/2 inch (1.3
cm) larger than the second patch.
(4) Apply one coat of 3985 cement to the large patch
and one coat of cement to the second patch; allow to dry.
(5) Reactivate both cemented surfaces with freshner No.
C-3339. Position two cement surfaces, centering the small
patch on the larger patch. Roll and stitch thoroughly.
Use separate brushes for the 3985 cement and
the C-3339 freshner. Do not use the same brush
in more than one cement.
C h a n g e 3