PVC is common stuff--it's in your walls and can be found dirt cheap at any hardware store. Would be very easy to scavenge up post-collapse. Durable, too.
With some gentle heating - in an oven, indirect heat over a campfire or BBQ, using a heat gun, whatever - you can get it nice and bendy. Insert knife for be sheathed and flatten the PVC pipe between boards. You can form a belt loop out of the PVC or use some cordage. Pretty simple, quick n' dirty. Paint if desired.
From Randy -
Natives by mid 1800 were using what the White men were throwing away. We are the Natives of today. There is a ton of this stuff laying around. Kydex material is expensive so if ya'll are going to use this crap I have to find an alternative re-use material for my End of the World Brothers. You could also texture it while it is still warm with leather stamps ..etc..
Not fancy, but functional and inexpensive. Common man, TEOTWAWKI recycling stuff. And of course, there's all kinds of other stuff you can do with PVC pipe - caches, blow guns, quivers and on and on. Good stuff to have.
A PVC sheath like this is especially good for inexpensive machetes that come without anything. It doesn't make a lot of sense to drop $50 on a good sheath for a $5 to $15 machete. Some PVC, heat and a bit o' work would do the job.
I have a beater Cold Steel panga machete that currently rides in a rigged cardboard/duct tape sleeve, and I'm going to have to give this a try. Was planning on doing it today, but real life and work threw a monkey wrench in that plan. I will post a step-by-step when I get it done.
Big thanks to Randy for passing this along! Check out Church & Son's to peruse more of his knives.