We couldn't afford the
sailrite machine, so looked around and bought a Janome HD. Very basic all mechanical with
steel drive train and
aluminum body. It has no problems with 5 layers of sunbrella and a plastic window at the same time. Used it to see new
cushions throughout the
boat as well. This involved in sewing through 4 layers of
marine vinyl which it also did with ease.
YouTube has videos of people sewing through
wood yardsticks with these things.
Look for a heavy duty machine with no electonic gizmos. Most can handle thicker cloth and even some sail
work with care. Old thrift store units can be good, but note a good older machine will likely be very heavy due to the solid
steel construction.