This is an unusual method of joining 2 sets of live sts, but it’s worth the effort as the finished result is neat and structural and really rather decorative.
As with any I-cord bind-off or applied I-cord, you will want to cast on or pick up sts as per your pattern instructions. If this is to be the edging on a circular seam or similar, then you may wish to provisionally cast-on, so that the beginning and end can be grafted together to complete the seam free look. Alternatively, you can cast on 3sts as you would an normal I-cord. Or you could pick up the sts from a bottom edge.
This is another technique used in my Asymloche pattern but it can of course be used anywhere where a decorative, structural seam is desired!
1) After casting on, work one round of purled I-cord (just the same as a knit I-cord, only the sts are all purled) then with the yarn at the back, transfer the 3 sts to the left hand front working needle. As with the 3-needle bind-off, you will want to have your live sts held parallel, with WS together and RS facing.
2) Bring the yarn from the back to the beginning of the purl sts, and purl the first 2sts. Keeping the yarn in front, slip the next sts to the right hand working needle.
3) Bring the next stitch on the back needle to the front needle
4) And purl it together with the next st on the front needle.
5) Then pass the slipped st over the p2tog just worked. Slip the I-Cord sts back to the left needle and repeat from step 1. Continue until all sts have been bound off, then finish the I-cord by drawing through the remaining sts, or grafting them to the edge of the fabric (dependent on pattern instructions)
6) To compensate for the differences between row and stitch gauge, and to avoid any puckering, you will want to work one plain round of purl I-cord every 3 or 4 joined/decreases sts.
As always, if you have a question about this technique or need some help with it, leave a comment below! I’m afraid I’m unable to offer help via email or private message but you’re welcome to post in our forums.