I got the idea for this while at a local Goodwill. I saw a turtlneck sweater that I was pretty sure I could make work. On half off day I paid a whopping $3.50 for the sweater. Any type of turtleneck sweater would do but I made mine out of soft merino wool as wool stays warm even when wet.
Step 1: The Sweater - Choosing, Cutting and Sewing.
The sweater should be tested for fit. If you can slip it on over your head and you are comfortable with the way it feels it sould work fine. If it is a LITTLE snug or a little loose that is ok.
Turn the sweater inside out and lay it out for cutting. (see pic 1a) How you cut depends on the fit test you just performed. If it was a little tight or just right, cut so that the lines angle out slightly. If it was too loose, cut so that the lines angle in slightly.
Using your sewing machine set to stretch stitch (see your manual) stitch down either side starting where the neck piece joins the sweater. You are creating a long tube. (see pic 1b)
Step 2: The Fold - Care
Start turning the tube inside out on the wide end. (see pic 2b) You want to end up with the wide end of the tube folded over the narrow end, wrong sides together. (see pic 2c)
Slip it over your head for a test fit. If it is too loose you can unfold and stitch down one side to narrow it up a bit. If it is too tight give it to somone with a smaller head.
Note, if you make this out of a wool sweater DO NOT WASH IN A WASHING MACHINE. The agitation of the machine will felt your gaiter and you will end up with something that your kid's doll can wear. Wool must be washed by hand. Not need to use fancy washes, I use Panteen shampoo with conditioner. Wool is hair and Panteen makes it smell nice and the more it is washed the softer it gets.
To wash a wool gaiter: Add some Panteen or other shampoo to a bowl of warm water. Unfold the gaiter and do a 20 minute soak with very little agitation followed by a warm water rinse. After rinsing, gently squeeze as much water out as you can. Try not to stretch or twist a wet wool garment as it will lose it's shape. Lay out a clean towel and spread the gaiter on top of the towel. roll it up and walk on it barefooted. This will pull out more water and make it dry much faster. Lay it out on a sweater rack or something similar till dry.