Cushion Troubles

[jojo]

So I'm doing these cabin cushions. The originals were covered in 1970's burnt orange chenille (top and boxing) and the bottom is vinyl.
The customer picked a microfiber fabric, and I figured I'd do the bottoms in vinyl. Sewed the welt to the top microfiber plate and the bottom vinyl plate, and while the vinyl piece looks fine, the welt has twisted on the microfiber plate and not it's won't lie flat and is misshapen.
How can I remedy this?
At first I thought it would straighten out once the boxing was sewn on, but when you compare the top to the bottom, they don't match at all (the microfiber appears shrunken), and I'm so afraid the corners will get twisted on the finished product.

[sofadoc]

Did you pre-sew the welt? That might help. Micro-fibers can be pesky.

[jojo]

Thanks Doc,
No, I never pre-sew in the interest of saving time. But I will try it now. Btw, should have mentioned that I'm using the foam core welt - do you think that might be contributing to the problem also?

[sofadoc]

I never use foam core welt. But I've seen some that came out really wavy.

[MinUph]

Foam core is good for marine use. It doesn't absorb moisture and allow mold to grow. It is prone to rolling if not taken off the roll properly by unwinding and keeping it as straight as possible. I take it off the roll from the bottom on a rack if at all possible.
 

[Mike]

I only use foam core and and I also always presew I have had fabrics twist I found it to be too much thread tention

[kodydog]

Use both hands to pull the fabric through the machine. One in front and one behind the foot. Slightly stretch while sewing. Microfiber is one of those fabrics that does all kinds of weird stuff while working with it.

[gene]

With some fabrics, I can pre sew my welt cord so that the welt cord is spiraling. It does not lay flat.

When I sew this spiraling welt cord onto the fabric panel the spiraling welt cord makes the fabric panel not lay flat.

If you did not pre sew the welt cord, you may be sewing spiraling welt cord onto the fabric panel. Hence, the wisdom in sometimes pre sewing the welt cord to make sure it lays flat.

I can also sew my perfectly flat pre sewn welt cord onto a fabric panel in such a way that the fabric panel will not lay flat. If I stretch the fabric panel as I sew, this can cause the finished panel to not lay flat. As I start and stop my sewing, sewing about 6" at a time, I am actually sewing 5 1/2" of fabric (stretched out to 6") for every 6" of welt cord, for example.

Using a smaller stitch length, sewing slower, using straight pins, using fabric adhesive on the edges and letting it dry in extreme cases, following the advise of the folks on this forum, cussing and throwing the cat up against the wall, have all been helpful techniques to get my fabric to lay flat. (Before you sent PITA to my door, it's a stuffed cat. I had it stuffed after the first time I threw it up against the wall and killed it.)  :)     :o  8)  ::)

Don't forget that fabric can stretch more on one side than the other, and especially the bias.

gene

[jojo]

Thanks, all. I will follow all of your suggestions, and one I saw on a Sailrite video. The instructor on the video said to put the welt in a pot of boiling water for a few seconds to "relax" it. Can't hurt to try it, right?

[jojo]

Update: Boiling the welt really has made a huge difference! I haven't sewn it yet, but all the kink came right out of it after about 10 seconds in the water.

[Lo]

I just went through a twisted welt mess of an issue with Sunbrella and jute cord. I ended up stapling one end of the welt to the table and then worked it out like pulling taffy ... all attempts at the machine did no good with this tight weave. Have used same approach with other pesky fabrics as needed ... microfiber being one. Must be an OCD thingy with wanting the welt to run smooth and not have wobbles or waves :-)

[baileyuph]

I don't use plasic filler in cording for furniture, several reasons other than discussed.

But, given the boiling water dunking trip worked, a question:  "Do you think steaming the sewn in welt "twist" problem would help?  Maybe some one has tired and has an answer?

Doyle

[Nunyo]

I don't use foam or plastic welt in fabric only in vinyl . I found it is hard to get the welt to lay straight. But the main reason is its to hard at the corners and wears through the fabric

[bobbin]

I don't use the foam core welt on lighter weight fabrics anymore.  For exactly the spiraling you've encountered, Jojo.  A couple of years ago I had a helluva time with a velour fabric that had a knit backing.  It was just awful.  I ended up moving to 69 thread, loosened the tensions, and shortened the stitch length.  It was better but not perfect and certainly not easy.  I made a mental note to diversify welting and thread sizes in my own shop. 

I use the 100% polyester welt from Rowley a lot when faced with lighter weight fabrics.  I really like it.  And I really like the idea of brewing a batch of the foam welt! that stuff can be just brutal when you get down to the end of the roll.  I wondered the same thing as DB, but wasn't thinking about steam as much as I was thinking about using a heat gun on a lower setting?   

[mike802]

I have had good results by taking a seam stretcher and pulling the sewn cushion tight along the welting and steaming.  I mostly use Fiber Flex welting, but will keep the boiling idea in mind for the foam core.