Perfect for Burning Man, lazy Sunday afternoons or hand-to-hand combat.
Start with an empty propane tank. The bad news is, you can’t empty a propane tank by just burning off the contents or bleeeding out the last bit of it by inserting a tool into the valve. Propane remains – along with methyl mercaptan, the horrible-smelling chemical added to otherwise odorless propane. So the tank is still dangerous and should NOT be worked on with or near tools that cause sparks.
I fashioned a valve wrench out of 2-inch-diameter aluminum SpeedRail, but any stout metal pipe will do.
I then ratchet-strapped it to a post and put a bar on the wrench to get the needed leverage. It takes a *lot* of leverage to break the seal.
Once you’ve unscrewed the valve, take the tank – which still contains propane and methyl mercaptan residue – immediately out back and fill it with water and dish soap. Leave it overnight, then dump it and rinse and drain it dry.
I’ve written about this before, but do *not* attempt to build one of these unless you know how to safely empty a propane tank and get the valve off ot it. Just don’t. Anyway, beginning with an empty, de-valved tank, you start by using ViseGrips to break the welds holding the base in place. You have to wrench pretty hard back and forth to weaken the welds till they snap, but there are only 3 or 4 of them.
I then used an angle grinder to strip off all the paint and grind off the welds from the bottom of the tank.
This leaves a nice, textured finish.
Laying out the pattern with a compass and Sharpie. The concept of building tank drums from propane tanks should be credited to Dennis Havlena, a Michigan instrument-hacker who made his first in 2008 – (plans are here) A lot of people took up Havlena’s open-source idea – some even took off into manufacturing them.
I found a video at one maker’s site that had a tuning I liked, and hand-sketched a 10-key drum based on that design.
Here’s the pattern sketched in with Sharpie.
. Now drill holes at the corners of all the key edges. This lets you bring two cuts together cleanly without making an X if you cut a little too hard.
Then you get to making the rough cuts with a Dremel, top speed, with thin-grade reinforced cutting discs. I go through 8-10 discs during the whole process.
You cut each key a little short of what the template suggests, tape off all but the key you’re tuning, and then use a smartphone tuning app to find what the pitch is on each one.
You can find a few good tuning apps on the App Store – I’m using insTuner.
If a key is sharp – say, an E is ringing at D#, you cut it longer. If the key is flat, you have to carve off the end of the key to shorten it and raise the pitch.
After a lot of tuning (cutting takes a couple hours, and tuning properly can take three or four more) it’s mask and paint time. I’ve already sprayed clearcoat all over the keys, since I liked the way my sketched-in keys looked and wanted to preserve the design process. I then masked it off and sprayed a thick coat of yellow. I purposefully laid on a bit too much so the paint would drip and run a bit.
I sprayed the middle of the drum with this wild green mealflake model enamel I’ve had sitting around forever, and then sprayed the handle in black.
I wanted to add a little accent color, so I masked off triangles at the base of each key and used red Testor’s model paint.
Then – I don’t know what the f$@k came over me – I proceeded to over-pimp the triangles with Sharpie and metallic markers, and the whole thing wound up looking absolutely garishly awful. So …
I masked off everything but the level containing the ugly, and put three thick coats of yellow over it so it would blend with the rest of the top- laid on stripes of masking tape at regular diagonal intervals, sprayed the exposed stuff with black …
… et voila. No less garish, but at least it doesn’t look like a hippie barfed all over it. I even managed to keep a little bit of the detail that I did like.
I epoxied a chunk of slit garden hose to the handle to act as floor protection for the base …
I also found a terrific substitute for the damping material. To help the keys ring well, you have to nullify the entire body of the drum from ringing and overpowering them when you play. On “Little Boy,” my previous 8-key A-minor drum, I used a chunk of garden hose wrapped 7 times around the center, anchoring the ends with metal screws. On this one, I found that self-adhesive rubber strips used as non-skid-plates for stairs worked perfectly – and fit in beautifully with the aesthetic.
If you would like me to make a drum for you on commission, the price is $300 – $250 if you bring your own empty propane tank. Contact me for details.