Welting issue

[MinUph]

We have been having this issue with pillows. I know it has been seen before and can't get past it. Two of our seamstresses have had the same issu. Any comments on why?

[sofadoc]

I've seen that on some really stretchy chenille fabrics. And for some reason, many factories use PVC welt with those kind of fabrics, which IMO only compounds the problem.

[MinUph]

This is 5/32 standard welting. Not a fabric that would normally do this sort of issue. Bias welt also.

[baileyuph]

Not being critical but analytical:  Rip the cushions apart and compare the two templates for equal dimensions (suspect they will be).  Then, if that is a yes, chalk some regisrations marks along the four sides to veify equal fabric flow when seaming.

Might let us know what their sewing sequence is.  Assumption is, this isn't tension related.

Let us know when you figure it out, which I expect you will.

Doyle

[sofadoc]

compare the two templates for equal dimensions

On throw pillows like that one, I don't cut 2 equal plates. I cut one to appropriate size and sew the welt to it. Then I flip it on top of an oversized one and sew them together. Then I trim the excess from the oversized plate.

I've seen that wavy welt problem on factory jobs. But I don't recall personally having that problem.

[gene]

Let's say the pillow in your picture is 16" x 16".

If both pillow panels (top and bottom) are 16" from corner to corner, and the welt cord is 16" from corner to corner, then you cannot get that kind of snaking. With everything being equal, even if you put a big, fat, plump insert in the pillow cover, it will only pull the sides closer together and make more of a 'dog's ear' on the corners. The insert does not cause snaking on a properly sewn pillow cover.

One of the panels, both of the panels, or the welt cord are not all 16", in my example.

Either the top panel is being stretched or shortened when welt cord is sewn onto it, or the bottom panel is being stretched or shortened when it is sewn onto the top panel that already has the welt cord sewn onto it. (If you do your pillow covers the way I do mine.)

Test: Sew the welt cord onto the top panel, attach the bottom panel at the bottom corners, add the zipper, and then staple or pin the bottom panel onto this top panel on the other 3 sides and sew away. If the snaking is not there, then the problem is what I described.

If your sewing machine is OK and not differential feeding the fabrics, then a smaller stitch and a slower sewing speed can help.

I too have found this happens on specific fabrics.

gene

[bobbin]

I agree with all above.  Some fabrics are more "squirrelly".  This is most likely not a "machine issue", but an "operator issue".  

1.)  experiment with different welts for different fabrics.  (I have 3 types in stock, all 5/32)
2.)  I mark the centre of every piece I cut.  Habit, and it allows me to identify "issues" early on.
3.)  I always use bias cut welt.  
4.)  Faced with a loose weave that I suspect could be "trouble" I bump up the differential on my overlock when clean finishing the welting edges and also on the basic cushion pieces.  This has the advantage of stabilizing the fabric and lessens the likelihood of stretch.
5.)  I have the advantage of adjusting the "walk" on my Juki 1541 and I use that feature a lot. 
6.)  I only use the vinyl welt insert on vinyls or really stout Sunbrella... everything else gets a welt insert with a softer hand.  I use a polypropylene twisted variant for really loose weaves or stretchier knit backed fabrics.  

I have a lot of garment experience that demands learning how to "ease" (shoulder caps, lapels, underarm seams on tailored items).  I don't flip out when "ease" seems overwhelming (this is why I always mark the centre of any seam).  If you wish to learn how to "ease", work with a tailor and "do your time" in the garment world. You learn how to "work" fabric to achieve a result.  This detail is the subtlety that escapes many.  It's what's allowed me to excel at cushions, pillows, and slipcovers!

[kodydog]

If its an over stuffed issue try adding a bow to the edges like you would to a down cushion. 1/4" to each side may help.

[gene]

I made two knife edge pillow covers with self welt cord today.

The fabric is linen with a dot pattern. The dots feel like some type of rubber/ rubberized material. The paperwork said "patent pending". (Very high end "New York City" fabric.)

I sewed the face panel (top panel) on top of the welt cord. It snaked worse than that scene in the garden of Eden.

I took the welt cord off, and without changing anything on my sewing machine, I sewed the welt cord on top of the face panel. No snaking. It laid flatter than a squirrel in the high speed lane of a major freeway.

The fabric was being stretched when it was sewn on top of the welt cord. The fabric was pulled along even with the welt cord when the welt cord was on top. This does not happen on all fabrics. I will sometimes sew the fabric on top of the welt cord to get a more flat lay.

I wonder if fabrics collectively are the most variable material to work with - more than metal, wood, plastics, etc.

gene

[MinUph]

Fabrics are definitely more variable than wood or metal. Interesting find gene.

[Dede]

I agree with all above.  Some fabrics are more "squirrelly".  This is most likely not a "machine issue", but an "operator issue".  

I agree, but operators need to know and understand how feed dog action affects "ease" on a straight-stitch.  Experience leading to professional intuition just isn't possible without it.

I was already sewing professionally when a friend joked that she remembered bottom layers feed faster by thinking "the 'dogs' are hungry."  This led to an epiphany; I had never really considered it before.  And my sewing became much better and far more intuitive.

5.)  I have the advantage of adjusting the "walk" on my Juki 1541 and I use that feature a lot.

Seriously?  WHERE IS THIS FEATURE LOCATED??!!

[bobbin]

The feature is a dial atop my Juki 1541N7.  I can adjust the step height of the inside foot by turning it.  If I'd really been "on my game" I'd have added the option to make it pneumatically controlled (like the automatic presser foot life and one stitch back function) although that would require I run the compressor daily (which I don't generally).  Tack and trim work without air, but the automatic presser foot lift function requires it.  I generally run my machine with the knee lift bar in place.

[Dede]

The feature is a dial atop my Juki 1541N7.  I can adjust the step height of the inside foot by turning it.

Ah... that's it.  I have an early production model.  Doesn't even have the legendary safety clutch -- wasn't even available as an option.  *weeps uncontrollably*