TM 10-8400-203-23
I
2-6. REPAIR AND MAINTENANCE OF PNEUMATIC MATTRESSES–Continued
(c) Allow the cement to dry at least 10 minutes, then press the two parts of the seam firmly into place.
Allow the bonded seam to dry at room temperature 18-24 hours before stitching. (Proper drying
will allow the seam to develop optimum green strength; incompletely dried cement will cause
debris to form on the needle).
(d) Stitch along the seam, 5/16 ± 1/16 inch (0.79 ± 0.15 cm) in from the outer edge. Start 2 inches
ahead of the defective portion of the seam and stitch 2 inches beyond it.
(e) Seal the stitch holes with 3 coats of the cement, allowing 10 minutes drying time between coats.
When the final coat has dried, dust with talc or mica dust.
(f) Allow the sealant to set overnight, then inflate and test for leaks. This may be done by immersing
the repaired edge in water, or by applying soapy water. Alternatively, the inflated mattress may be
allowed to stand overnight; although this method will not give the location of any leaks that maybe
present.
f. Repair of Blown-Out Border Seams.
(1) Recommended sewing machine equipment. Use the finest practicable size chrome plated round
point needle. Teflon presser foot, knurled feed dog, Singer needle cooler. Thread may be run over a
pad saturated with water. Use no wax, oil, or grease thread lubricant. Avoid high sewing speeds. Stitch
Type 301; 8 to 10 stitches per inch.
(2) Repair procedure. The repair consists of cementing together the separated border seam, stitching
the seam along the inner edge, and sealing the stitch holes. The detailed procedure is as follows:
(a) Open the blown-out seam so that the seam separation extends the full width of the seam, i.e., the
separated area is squared off.
(b) Prop the seam open and apply a heavy coat of cement to both sides of the open seam. (Excess
cement beyond the seam will do no harm).
(c) Allow the cement to dry at least 10 minutes, then press the two parts of the seam firmly into place.
(Incompletely dried cement will cause debris to form on the needle.)
(d) Stitch along the seam, 5/16 ± 1/16 inch (0.79 ± 0.15 cm) in from the outer edge. Start 2 inches (5.1
cm) ahead of the defective portion of seam and stitch 2 inches (5.1 cm) beyond it.
(e) Seal the stitch holes with 3 coats of cement, allowing 10 minutes drying time between coats.
When the final coat has dried, dust with talc or mica dust.
(f) Allow the sealant to set overnight, then inflate and test for leaks. This maybe done by immersing
the repaired edge in water, or by applying soapy water. Alternatively, the inflated mattress may be
allowed to stand overnight, although this method will not give the location of any leaks that maybe
present.
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