Sometimes I get a good looking row of stitches on top but on the bottom of the fabric is an unruly mess. What causes this. BTW, I have an old (1921) Singer with a walking foot. Fabric is vinyl.
I am trying to sew a welt into a seam. Four layers all together. When I do this the above happens more often than not. I think it is probably tension adjustment but I don't know which way to adjust. (tighten or loosen?). BTW if I simply place 5-6 layers on top of each other the machine sews quite well.
All advise appreciated.
Thanks,
Ivan Vegvary