Reap What You Sew
Do Your Own Upholstery, Part II: How to Set Thread Tension and … Sew (Finally)
Do Your Own Upholstery, Part 2: How to set thread tension and ... sew (finally)
O K, we apologize. Last month trimmer Jerry Glasgow at McFarland Custom Upholstery showed us the way around a commercial sewing machine. Lured by the prospect of one day doing your own upholstery, maybe you even went out and even bought a machine. But now what? I mean knowing how to thread a machine is a tremendous tease if you don’t know how to actually use one.
That changes this month. Yeah we’re still pressed for space and all but after practicing what Glasgow reveals here, you can honestly say you can sew together at least two panels.
We’ll cover a few very critical (but simple) things. First, we’ll learn how to set thread tension to execute a strong, reliable seam. As part of explaining seam allowance means, we’ll show you how to stitch together two panels. Then we’ll learn how to measure how panels “shrink” when sewn together. Then we’ll show how to make a simple seam a whole lot stronger and better looking. We’ll finish up with how to stitch outside and inside curves, two of the building blocks in the trimming world (the straight seam is the third).
Yeah, we still have a little ways to go. But taken a little bit at a time, you too may one day brag that you did it all, even the upholstery.
How to Set Thread Tension
If you were to X-ray a stitch, you’d discover that it’s basically a series of interlocking loops not very different from the wires in a chain-link fence. The needle moving up and down is but one half of this loop-making process. The other half is the bobbin hook. As the needle moves up and down, the bobbin hook spins round and round. As the needle descends through the material, the bobbin hook swings up to grab the needle’s thread. The hook swings back down, taking the needle’s thread with it. During this trip down, the needle thread and bobbin thread cross to make that loop. As the needle ascends, the take-up lever pulls up on the upper thread, thereby pulling the newly formed loop into the stitch hole.
Now, if the needle and bobbin thread tension match, the two threads will intersect within the material. But if the thread tensions don’t balance, the tighter thread will pull the looser one to its side. And a poor-quality stitch will follow. Fortunately there are only two adjustments.
Because few materials behave exactly the same, set the thread tension each time you change materials. It takes just a few stitches in a couple remnants. This is how to do it.
The other half is how the stitch looks from the bottom. Just as with the top, the material should dimple slightly and you shouldn’t see the topside thread. Glasgow says the only exception is when a slight glimmer of topstitch can show on the underside stitch.
Here’s how a perfectly executed seam looks from the topside. The material should dimple slightly from the pressure and you shouldn’t see the thread from the bottom stitch anywhere on the topside.