This may be incorrect forum? I created my own external curtains on a 1986 SR AJ but don't remember what gauge of clear vinyl I used for them. I believe it was 20 gauge but it may have been heavier. I understand that there is 40 gauge now available, but I don't know if my old Singer or Kenmore sewing machine will penetrate the vinyl sandwiched between two layers of TOP GUN fabric that I plan on using to hold the snaps. Also, are there any companies who make separating zippers that have an adhesive backing that I can tape onto curtains and sew into place? This would eliminate pinning zippers into place. Any suggestions or videos would be appreciated!