I use to have a Sailrite Sailmaker machine when I was sailing. I could sew thru heavy dacron sails with it and also Sunbrella for making bimini covers. It was one heavy and very tough machine. It wasn't cheap, but was the only thing I could find that could do sails and wasn't an 'industrial' machine. At the same time I had a White Jeans Machine that I was told (by the salesman) could sew thru 12 layers of denim. NOT! Hated that machine.