Neoprene
fabric is a synthetic rubber material that is used in
products that are designed to be both flexible and durable. It comes
in several foam styles and densities with the most common and least
expensive being an SBR foam. Most neoprenes have a laminate such as
a nylon Lycra or Velcro loop on one or both sides. It comes in
thickness from 1.5mm to 7mm.
Stitching Techniques
Any neoprene over 4mm in thickness will be difficult to
sew with a home sewing machine and should be glued edge to edge.
Overlock:
The overlock stitch is the easiest, least expensive stitch. It is
very durable but when used on a garment may cause discomfort due to
the ridges left on the inside. (see edging below to soften ridges)
Flatlock:
The flatlock seam provides both durability and comfort. This
technique requires taping to hold out leakage from the seam holes.
Gluing the joint adds additional strength. A double stitch will
provide a much stronger hold than the single stitch.
Needle
You will have better results using a large needle such
as a Universal 16 or 18. The smaller needles will not make a large
enough hole to allow the thread to pass through easily. Neoprene is
sewn best with longer stitches which depend on the neoprene
thickness and your sewing machine. Experiment with stitches until
you get the results you want. Your needle will heat up with the
friction of sewing through the thicker neoprene so go slow to avoid
melting your thread.
Seam Sealing
Gluing: Use a seam sealer that is made for
Neoprene such as
McNett's Aquaseal. Gluing the seams together
before sewing will increase the durability of the seam.
Taping: The pieces are glued or sewn, then a
heat sealable tape is applied across the seam. This method insures
a waterproof seam. Use a Melco or Bemis seam seal tape, preferably
meant for sealing against nylon tricot fabrics. You'll really want
to experiment with scrap pieces here as getting the correct
setting/time/pressure to get the tape to bind without damaging the
nylon cover or neoprene foam.
Edging
Add a strip of Lycra or
fold-over elastic that has
been folded in half around the rough side of the neoprene edge.
This will create a non-chafing surface. The item on the right was
sewn together with a flatlock and the raw edges finished with Lycra
binding.
If
you have used an overlock stitch to join the neoprene edges then you
may also want to “smooth” out the seam by taping a
Lycra binding or elastic over the seam like this shown here.