TM 5-1940-321-13&P
( 3 ) Remove the keel using a heat gun to unglue the keel from the craft bottom
fabric. Proceed slowly when ungluing to avoid damaging the fabric coating.
( 4 ) Replace the keel valve metal insert and inflate the keel. Replace the valve cap.
( 5 ) Perform the air leak test (chapter 6, paragraph 6-3) to locate all leaks, marking
the leak locations with a silver pen. Deflate the keel.
( 6 ) Patch the leaks as described in Appendix F using strongan fabric, MEK solvent
and polyurethane glue. Wait 24 hours to allow the glue to reach adequate bond
strength.
NOTE:
If the keel has numerous leaks and the fabric is extremely worn, a new keel
should be installed.
( 7 ) Inflate the keel. Perform the air leak test (paragraph 6-3) to verify that all leaks
have been corrected.
( 8 ) Reinstall the keel by gluing or perform the Velcro modification described in
paragraph b below. If the keel is to be reglued, carefully note the points at
which it was previously glued to the craft s bottom fabric. Reglue the same
points. The keel is not glued all the way aft to the transom. The glue joints
should stop 4 inches forward of the transom. All regluing should be
accomplished in accordance with Appendix F using MEK solvent and
polyurethane glue. Lightly scuff the material to remove old glue. The weld at
the aft end of the keel should be folded and butted against the transom.
Establish the keel against the transom before gluing the keel to the fabric
bottom. Start gluing the keel from the transom, working forward.
b. Keel Velcro Fastener Modification. This modification is performed by direct support
maintenance personnel. Instead of regluing the keel to the craft bottom fabric, Velcro loop and hook
fastener tapes may be installed. This allows easy removal and reinstallation of the keel and greatly
simplifies removing and reinstalling the keel for cleaning, inspection and repair. The modification is
accomplished by sewing three 2-inch wide by 18-inch long Velcro tape strips to strongan fabric strips of
the same size. The strips are then glued to the keel using MEK solvent and polyurethane glue as
described in Appendix F. One long 2-inch wide Velcro strip is sewn to a 2-inch wide hypalon neoprene
fabric strip which is glued to the bottom fabric using toluene solvent and neoprene glue. Figure 7-32
provides all necessary information to accomplish the modification. Wait 48 hours after gluing before
installing and inflating the keel.
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