Sewing - Drysack
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- Dual layers of waterproof-breathable fabric, with wrong sides facing, protects waterproof-breathable membrane from abrasion.
- Dual layers have no common seams other than at the opening, so likelihood of water penetrating is negligible, unless sack is cut somehow.
- Because fabric is waterproof-breathable, water which penetrates first layer and get trapped between layers can easily evaporate.
- Closure is by folding top of sack. This is sufficient for rain which leaks into neckpurse or backpack, though not for submersion.
- Final weight depends on fabric. I used 3 oz/sqyd 2-layer Goretex Paclite with polyester ripstop face fabric from therainshed.com, which gave final weight of 70 grams.
- .5 yard lightweight 2-layer waterproof-breathable fabric.
- 100% polyester thread, 80/12 universal needles.
- Seamgrip by McNett or similar seam sealer.
- Cut two pieces of fabric 13" x 40".
- Fold fabric so that it is 13" x 20" and sew together on long sides with 1/4" seam. Repeat for other piece of fabric.
- Seal seams. Allow to dry. Dust with talc or corn starch so sealer will not stick to itself when sacks inserted inside one another.
- Turn one sack inside out and insert inside other sack. Sew together at top. Fold over twice to make 3/8" hem.