Sergers, 3 thread or 4?
Hi everyone, I'm not new to sewing and serging but am interested in purchasing a second serger for my daughter and am thinking a 4 thread model would be preferable to a 3 thread. I've had mine, which is a 3 thread, since the 80s and haven't thought much about it, until I started shopping for another. What is the advantage to having 4 threads?
Also, I'm having a problem with not being able to make my seams tight enough with my present serger and am wondering whether that's due to being a chowderhead and not having the tensions adjusted right, or if it's due to an inherent characteristic of the 3 thread sergers. I make my own exercise wear and the seams on the legs of my stretch pants always pull apart so I just go over everything I've done with the serger with the sewing machine to make sure the stitching is tight enough. That's labor intensive so I'd rather avoid that step, either by figuring out what I'm doing wrong, or by buying the 4 thread serger if that's the issue.
Thanks in advance for your input.