I repair a lot of jeans and find a notion called a Jeanamajig or a hump jumper, good for sewing over heavy places. I have always used size 16 needles and all cotton thread. I prefer Dual Duty, but sometimes it breaks. I have had to resort to beeswax or Thread Heaven on occasion. I use the Janome now. I used to use a blue Singer, but it eventually wore out. The 201 can do it. The needle is the crucial part. I have had it cut the thread, if the needle wasn't large enough, but it always went through. In fact that is when I started putting "gussets" in the crotches instead of sewing through that huge lump. Have you ever counted how many thicknesses are in it? People who wore the jeans with the gussets said they were really comfortable. Just cut a diamond-shaped piece and ZZ it down and then trim out the inside layer. I've probably broken hundreds of needles over the years though. Good luck. Oh, wear glasses.
Originally Posted by
ThayerRags
Always size the needle to the thread that you’re using, not to the fiber being sewn, and you’ll have the best luck. Larger needles need more punching power.
My wife sewed many, many embroidered patches on our leather vests with a plastic-geared JC Penney 7057. The reason that she could do it, was that she used a size 11 universal point needle and Tex27 serger thread. She tried leather needles and kept breaking them. It doesn’t take extremely strong stitches to simply hold a patch on, and I know that you’re stitching for strength making a bag, so it’s an apples-oranges comparison, but a household machine can punch a thin needle through some fairly thick and dense stuff. They’re all going to work overly hard punching a size 21 needle through very much thickness. Just IMHO.
CD in Oklahoma