"Darning" with a sewing machine is a quick way to sew repairs without patches, planning, or much skill. It doesn't matter how rotten and worn away the cloth is to start out.
Make your stuff last forever. Save the planet.

My favorite Makassarese sarong had a big rip in the back. A sarong is a tube of cloth worn as a skirt by men and women in places where the weather is good and the food is tasty. Makassar is a city in Sulawesi, Indonesia.

When I wore this in Indonesia people assumed I was a Moslem scholar from Makassar because I had a beard, this sarong, and a long sleeve shirt. When they asked me about that I would lie and say "I'm from Canada" because at the time the U.S. was being run by madmen. We'd just invaded and bombed a bunch of countries. Usually the person would respond with something like "Is that in New York?".

Step 1: Rip Something

First we'll do something simple.
This sarong was getting weak from salt crystals from using it to change in and out of wetsuits.
The cloth is kind of thin but it's still there. Except for the big rip, which was getting too big for me to use anywhere I might want to have a political career.

This is a perfect candidate for zigzag darning.

Step 2: Get Ready to Zig

Get some thread you don't mind the color of.
If you want to promote mending and conserving, use garish contrasting thread.
This gold thread blends in pretty well with most colors.

Step 3: Get Even More Ready

Line up the edges of the rip so they're just touching.
Use the widest zigzag setting your machine has.
Start sewing a half inch away from where the rip starts.
Straddle the rip with your zigzag stitch as you sew along.

If you don't like the way the cloth is being pulled together,
reduce the thread tension setting by turning the proper knobs and screws.

If the needle fails to grab one side of the rip in places, don't worry.
If the cloth is so rotten the thread starts new rips, also don't worry.

Step 4: Frost Vs. Yogi

You may come to a branch in the rip.
Usually it's easiest to sew the vertical part of a 'T' rip first and then the cross-stroke.
Do like Yogi Berra: "When you get to a fork in the road, take it."
You'll be zigzagging up and down all these rippish roads multiple times.

Don't end up like Robert Frost:

"I shall be telling this with a sigh
Somewhere ages and ages hence:
Two roads diverged in a wood, and I--
I took the one less traveled by,
And that has made all the difference."

If the cloth is rotten, do another row of stitching next to that, and another, and another, until the cloth is all strong and reinforced. This is a great opportunity to use all those weird ornamental stitches on your machine that you'll otherwise never have a use for.

Step 5: Darning a Strap

This strap on my Duluth Pack was going to pieces. I encountered a sewing machine but didn't have any strap to replace it with. So I ran a bunch of straight stitching up and down the strap and bound the edges with some zigzag stitching.

I've noticed a couple of times that baggage inspectors didn't want to touch my bag. Since they are drawn from the class of vandals and thieves, I'm sure that having a much-mended bag like this is a sure protection against such persons.

Step 6: Binding a Frayed Edge

"A stitch in time saves nine" is the saying. With rewards like that in store, let's stitch all over everything!
This edge looks a bit frayed. We'll bind it strong with some zigzag.
No need to clean the wound, just go plowing over that fuzzy stuff with the stitching.

Step 7: Reverse!

When you get to the end, hit the reverse lever to stitch back over it. Repeat repeat repeat.
I'm using my foot so I can take the picture with my other hand.
This is how Jerry Lee Lewis would have sewed on stage if he hadn't been forced to use a piano instead.

and the finished bound edge. Good for another hundred years of hard use.

Step 8: Darning a Big Rotten Hole

What if there's no there there? What if there isn't enough cloth in the middle left to stitch into?
No problem. Set the machine for a straight stitch.
You are going to jump that canyon like Wile E. Coyote, taking steps across thin air.

Step 9: And Repeat

It worked! After a few stitches into good cloth, Jerry Lee the reverse lever and back across the hole again. Thread tension tends to pull the cloth together. If you don't want that to happen you'll have to pull hard on the surrounding cloth to counteract it.

Step 10: Darned!

Darned with reckless stitches
a squandering of golden thread
makes the the broken places stronger than new

Step 11: And Before!

Here's what the bag looked before the repairs seen here.
Can you spot the spot that isn't stitched in this picture but is in reality?

Turn here for the rest of the Duluth Pack story.