I'm having serious problems with Lastin. Two diapers I've made have blown out elastic in the leg after just a few washes. What am I doing wrong? I use a three step zig zag to tack down the ends, then sew a topstitched casing. I usually go over the zig zag twice, because it seems more secure. Is it possible that I'm tearing the Lastin in some way by doubling up the zig zag? I haven't taken one apart yet to know for sure what's going on. Any Lastin tips would be appreciated!
Lastin is great though!!
I sew mine in a three step along the seam allowance,i.e when I get to the seam allowance section which the lastin needs to be I simply sew about 1/4 inch onto the lastin with the straight stitch,then pull it taut and flip my machine to three step and then the straight stitch at the end for the last 1/4 inch!
It seems to work nicely,I have only ever sewn casings with regular elastic.
It is a fast way to work too!!!!
Yes, I too learned the hard way not to use Lastin just stitched at the ends. Twice I had to cut a slit at each end of a pocket casing to rethread another piece of elastic to replace the ones that snapped even before we tried out the diaper. Now I do the 3-step zigzag instead.
Jayne, what width Lastin do you use? Also, how far do you stretch it? I have been experimenting with 1/4-inch and 1/2-inch. It's very stretchy, isn't it? I've tried roughly measuring 1/3 of the final length as I stretch it to sew it down, but it's able to stretch even more. Do you stretch it as taut as possible or what?
I use a regular zigzag with my Lastin - there's a trick to it though. If you let the elastic bunch up while you're zigzagging it, there's the very probable possibility of the stitches totally missing the elastic altogether. This, in effect, works the same as putting Lastin through a casing - the ends snap, and the elastic just pulls straight through the channel of zigzag stitches!
So, if you use plain zigzag, just make sure the elastic lays flat, and that the stitches actually go through the elastic most of the time. As long as you do that, it works fine.