Blowpipe & Bag Cover

2026-Apr-05

Bag Cover

This weekend I sewed a bag cover out of an old pair of jeans. Turns out my pant leg is just wide enough to cover the bag, but I had to cut through the butt pocket. Now there’s a butt pocket on the bag, lol. I think it makes it look interesting. And it’s a folk instrument, we aren’t playing at Carnegie Hall here.

At some point I’ll take a photo and post it here. Maybe.

Blowpipe

I also made a bunch of blowpipe designs that didn’t work. One that I was really excited about was a membrane check valve using a butyl bicycle innertube for the membrane. It works great and would be low-maintenance, but unfortunately it doesn’t let enough volume of air into the bag, so I had to go back to the low-tech design David Daye used (this is becoming a trend).

Here’s my fancypants valve:

membrane check valve

Here’s the one I wound up using:

low-tech check valve

I cut a little bit of innertube and tied it onto the flat spot of the tube, then bent it down over the opening. Because the innertube isn’t completely flat, I filled in a bit of a gap with some vaseline. [Update 2026-07-08: petroleum jelly is a bad idea with butyl, the butyl absorbs it like it was water. There’s some fancypants materials engineering reason for this that uses the word “positive”. But if you want to use butyl, lubricate with silicone instead! I’m using vinyl upholstery fabric now.] It’s still not a perfect seal, but it seems to be good enough. I may revisit this later when I get a thicker innertube.

Bonus: Flute Tenons

The innertube also works really well as poor man’s cork for the flute joints: superior to the wound thread I was using before. [Update 2026-07-08: butyl innertubes expand when you lubricate with petroleum jelly. Also they’re messy and gross. I’ve switched to using embroidery floss to wrap flute joints, still using petroleum jelly to lubricate.] Both of the flutes I have sitting around are playing much better now on the lower notes (F, E, D), probably because my thread windings were leaking a little air, and the flute is extremely sensitive to leaks.

So that’s cool, I’ve got two pretty good flutes now.

What Remains

I’m just a few parts away from replacing the entire bagpipe: