I always use black vinyl with premade black welt cord, but now I'm doing a seat in the color cork and have to make the welt cord as I can't find the premade stuff in that color.
I'm wrapping the vinly strip around the poly cord and sewing it with a welt foot. I can't keep the edges aligned while sewing so I stapled the edges together. There must be a better way.
(https://forum.upholster.com/proxy.php?request=http%3A%2F%2Fi306.photobucket.com%2Falbums%2Fnn242%2Fmarko69_photos%2Fcork-welt-cord_zps82d12d0e.jpg&hash=d76a4f87bdb8ed41b357b040eb9646cd) (http://s306.photobucket.com/user/marko69_photos/media/cork-welt-cord_zps82d12d0e.jpg.html)
Are you cutting the vinyl on the bias? This will give you more stretch to the vinyl.
Is your feed dog pulling the bottom part of the vinyl strip through the sewing machine faster than the top part of the strip? I think it may be easier to wrestle with the vinyl to keep everything easy rather than to staple the edges together.
Are you using a big stitch, i.e. the fewest number of stitches per inch? This may help.
Are you sewing slowly?
Remember to keep the stitch away from the needle if possible, then when you sew the welt cord onto the vinyl you can sew close to the needle and your welt cord stitches won't be seen.
If you can get a handle on it, have you thought about sewing the welt cord strip directly onto the vinyl without first sewing the welt cord together?
I hope this helps.
gene
PS: I stitch in time... can sometimes take hours!
The way I do it, is to sew the two halves together away from the piping cord. I do that by having the foot ride along the piping cord, so the sew line is about 3/8" from the cord. Than as said above, when you sew it into the material, you only have one line of stitching and the strength isn't compromised.
What does it hurt if the edges aren't perfectly lined up here and there. It's on the inside ! The outside is what counts. After a while you'll see what works when you are folding your material over the welt cord to get a better result. I always made my own welt for the first 4-5 years I was doing this. Now I stock the white marine I use and make the rest.
You'll get the hang of it. You probably already have.
I'm back, I've had to work on my cars the last few nights, both had bad alternators.
I'll try some of the suggestions when I start on my next piece.
Yes on the bias cut. I cut my material a bit wide and sew in the cord as close to center as possible then I take a 1/2" strip of thin plastic and lay it against the sewn welt and cut it clean. Perfect size every time, super consistent as well, cut it with rotary cutter.
jeff
If you cut the strip to 1 5/16" it will work out just right. That is with 3-4mm cord. I have just done a run of it myself.
Ive dine a fee videos on here were i sew without a welt foot using polycord ridi g mumfoot on top. After cutting strips about 1 1/2" usualy by eye. Then if need be adter sewing i will trim it even sith sissors loke s arab o dont find it critical to be perfect on the inside. Not seen.
For double welt
I learnt a neat tri k here fron stephen.