How to build a gun that shoots wet towels?

Question

If you've never been in a shower fight you cannot possibly imagine the pain a wet towel can inflict..

_{Pete Williams, 12b Avergreen Road, 4th grade, likes Brussels sprouts¹}

---

A towel can be many things. It can be a means to wipe oneself dry after a dip into the cold wet. It can be a used to cover a chair before sitting, or coat an ugly cousin's face. It can be a friend in the dark. And, it can be a weapon.

Towels are the probably meanest armament to make it into the arsenal of grade schoolers and above. And while they may be perfectly confident with drenching their dry-off-implement before whipping it at each other; we are somewhat more ambitious!

Our plan is to create a gun with the following characteristics:

• can shoot wet towels ammunition
• mostly precise over a distance of roughly 3–4 lengths of a standard towel
• the ammunition should achieve this nasty whip-slap effect on skin that we know and enjoy from towel-fights
• make us the king of towel-fights

---

Q: How to create such a towel gun so we can achieve that satisfying wet whipping effect?

_{¹Honestly, what kid who on God’s green Earth likes these things? NO ONE, THAT'S RIGHT!}

Answer 1

Shooting

I was at a basketball game and the costumed entertainer was giving out T shirts using an air gun of some kind. The shirt was folded flat and rolled up with rubber bands. A towel would work just as well. A wet payload work work the same, if you adjust for the increased mass.

The range was considerable, shooting from the playing floor up into the lower tier of seats.

This is the first thing I thought of, and I think they are commercially available. But shooting a compact projectile is not what you had in mind. But, the only answer posted thus far does that, so I decided to mention it too.

Whip-slap effect

You did specify

should achieve this nasty whip-slap effect on skin

so this rules out a rolled up projectile.

You need to perform the whip motion. This means a device that grips one end and like a robot arm will shake it just like you would. It can be a simple piston, but with computer control to time the swing.

The problem is that you can’t throw a whip! The device is limited to holding the towel at one end. If you “cast” the whole towel, it will not do the whip thing.

So, make the arm long. It telescopes or unfolds to a considerable distance while imposing the whip motion, so the snap is delivered at the farthest reach.

If you want the effect without the same mechanism, consider just the tip that delivers the blow to the skin. A small corner is propelled to high speed (faster than you can throw) via a transverse wave moving through a tapered media.

But if you just want a square inch of wet cloth to hit the target at high speed (matching the hand towel whip, based on experiments), you can use an air gun that fires a wet wadded piece of cloth of about 2 square inches. Just the corner of the towel, in other words.

Practical issues

Today, you would not be able to bring a pistol-looking device into the locker room and wield it while people are showering. Just having it would be too much of a spectacle.

So make it not look anything like a gun. Any wand-shaped piece of sporting equipment, chosen to match what is around, is used to conceal the barrel. A hose can lead to a hidden compressor elsewhere, or make use of an existing compressed air source on the premises.

Answer 2

Compressed air gun

A younger and sillier me used to use PVC pipe, some glued on fittings, and a portable air compressor to give projectiles some oomph. You can absolutely blow parts of a fence out with baseballs that way, not that a mild mannered kid like me would ever do such a thing.

I hesitate to call it a potato gun, because we always used baseballs. The secret to success was learned watching Revolutionary War re-enactments: wrap the baseball in wet paper towels and ram it into the chamber using the axe handle. Then, when you blow the air in, you get a good seal the entire way down the barrel and pretty solid muzzle velocity (it helps if you grease the inside of the barrel with Crisco, too).

To adapt this for a towel, simply wad the whole towel up, soaked in water, and put it in the barrel. That should provide a plenty good seal for some serious muzzle velocity.

Older kid variant

As I got older, simple compressed air didn't do the trick any more. We needed FIREpower. If you glue a BBQ grill starter into a 'chamber' of a PVC pipe, then fill the chamber with ether (most combustible thing we found), you can then ram in your baseball wad and get a pretty good pop.

Make this even more effective by soaking your paper towels/actual towel in gasoline. Not only does that provide more fuel in your chamber, but also tends to send the payload out on fire. Especially useful for night fire exercises, though to be honest, I think the air cannon had more muzzle velocity.

Answer 3

Initial thought was a balled-up towel, but you want the sharp slapping effect, so I'm gonna go a slightly different route.

I'm thinking a design similar to a crossbow, except instead of firing in a linear fashion, a high speed arm moves in a semi-circle with one end of the towel (preferably with weighted ends to maintain speed and shape) before release, causing it to fly similarly to a bola or tomahawk, delivering the satisfying wrapping smack so iconic to wet towels.

It doesn't even need to be high-tech, you could probably build one spring-loaded with a trigger release. Especially at short/mid range without becoming lethal. Although practicality probably depends on what size is "standard towel", if we're talking skimpy-wrap hotel-pool towels, then definitely. But if we're talking proper large'n'heavy beach/bath towels then there might be a problem.

Answer 4

A bola-launcher, modified, should do the trick.

Since you're looking for the "whip-slap" effect, you need a projectile that is long, thin, flexible, and hits sideways. Obviously a whip is the first connection, but that's still at close range. The possibility I thought of for a longer range weapon, that has the same kind of strike, is the bola.

A bola consists of rope with heavy weight on the ends. It is swung and thrown, and it hits the target with the rope, letting momentum wrap the weights around the target to tangle. Obviously, since this is a weapon, the momentum behinds the weights striking can do a good deal of damage - not ideal for our purposes, and the reason the concept needs some tweaking.

So, the bola needs weights on the ends to make it easier to launch, otherwise there's no way for a light rope to get enough momentum. A towel would probably weigh less, generally, than a bola - but this is indeed counteracted by the weight of the added water. A towel would also have more mass in the middle, less on the ends. This would not be great for the spin-throw that a freehand bola uses, since the weight differential helps build up momentum, but since we are using a bola launcher anyway, that is less important. I think we will still need weights on the ends, for launching and stabilizing the throw, but they can be smaller.

With more weight in the middle of the towel and less on the ends, and greater air resistance to the volume and mass of a towel compared to rope, this "towela" is probably nudges itself out of the dangerous-weapon range and back into the merely painful category. I'm sort of picturing a longish, narrow towel with each weight connected to both corners on the narrow ends, for the little parachuting imagery it gives me.

On to the bola launcher. A bola launcher, from what I see, uses two parallel (and identical) mechanisms that grip the weights and launch simultaneously when the trigger is pulled. The mechanism could be similar to a (double launching) crossbow, or as complex as any mechanical launcher or firearm.

Our "towela" launcher would need to be somewhat stronger, as a wet towel will be heavy and the distribution of mass would mean more resistance - so more power needed to effectively launch the towelas. The loading mechanism would also need to be modified, towels being thicker and the connections to the weights would be wide and clumsy compared to rope connectors, making it harder to reliably grip and release the weights unless some thought went into it. It would take some practice to learn to balance factors like distance, strength, and materials to make precise effect desired, to quickly load, arm, and otherwise manage the towela ammunition, and to reliably aim at and strike the targets.

Of course, since we're modifying the towelas anyway, there are some extra possibilities. A cotton towel (think tea towels or dish towels) is thinner and lighter and so will need stronger weights than a heavier terrycloth towel, but can generally act more like a bola in strength and force. If the towel is straight between the weights, it will have more air resistance, less force, and more surface area hit than if the towel is twisted (it will then act more like a rope than a parachute). The towela can be loosely or tightly twisted for further control over the force vs resistance balance. And, it may be possible to add some padding to the weights themselves, to minimize the distraction from the blow when the weights land, in order to maximize the snap-whip effect from the towel's sideways blow.

Answer 5

So we are looking to create a weapon that causes the whip-slap effect at range. I think the power involved is called Torque. It needs the water in the towel to store the energy. With a pivot point to give it the momentum. Aka, whip.

Now, we don't want a long arm to dish out this wet towel whip-slap. That can get nasty in the closed environments where we do battle with towels.

---

The whip-slap Towel Catapult

Theory

Create a way to rotate the wet towel to hi speeds and send it off to intended target.

Now, in idea it is close to the Shuriken Catapults of the Eldar (Warhammer 40K). But alas, I could not find blue prints...

Build

So we have 2 round plates that hold the wet towel (smallish towel ~60cm (2 feet) diameter). Those are mounted on a frame that let's you spin them up to speed with a cordless power drill. When you hit the release button the spinning plates, with the wet towel, move ~1m forward over the frame. Here forward speed is created with rubber tubes (youtube) that work as springs. At the end of that open up a bit to release the towel. That will fly towards the target, Frisbee style.

I don't think you will be able to be sneaky, stealthy or fast with this one. But you will have reach. Maybe enlist someone to guard you while you reload and aim. (don't aim for the head)

Happy slapping!

Answer 6

Since there are already plenty of ways mentioned to fire a wet towel somewhere, I have an idea for the 'whip-effect'.

Above mentioned arms etc. are nice, but then the gun becomes a whip again, since OP wants a projectile, how about adding some "breaks" to one end of the towel.

You could use some kind of parachute or even retrorockets, put them on one end of the towel and fire it at your enemies.

Only problem is, that the effect only works for a precalculated/preconsidered range, since the parachute opens more or less always at a certain range, which restircts the range of the towel-whip. With retrorockets one could avoid it by remote triggering the ignition of said rocket to adapt the range of the "gun".

---

Little addendum:

In case you want to "pimp" your little shower friendly RAT-gun₁, you could add a water tank to your gun, to wet your towel prior to shooting some poor fellow. So the towel won't go moldy if you don't use your gun for a few days.

Added bonus, in case of zombie apocalypses, alien invasions or similar events, switching the water tank for a gas tank₂ could give you a little survival boost.

_{1Rocket-Aided-Towel-Gun, not to be mistaken with a device called Rat-gun, which fires vicious little critters and which should be banned in all civilized countries}

_{2A burning towel-whip-projectile, ignited by the retrorockets, has the potential to frighten even a well travelled alien. If the aliens win despite your resistance, at least they have to make new towels and will be hindered to hitchhike to the next planet for some time.}

Answer 7

Take the wet towel, give a mad scientist cackle, and combine it with a spear fishing gun and a T-shirt cannon.

First take your towel, roll it, and add a weight at one end. This weight must be heavier than the towel, even when the towel is wet.

Take the reel mechanism from the spear fishing gun. Attach the end of the line to the weight. Modify it so that you can, on the fly, stop it and control the distance at which it will stop. Add a winching return mechanism.

Attach the reel to the T-Shirt cannon. Beef it up to handle the additional mass of the wet towel, weight and line.

Take aim at your victim, pull the trigger, then hit the stop on the reel just short of the distance. The line snaps taut, causing the weight to suddenly stop, thereby whipping the other end of the towel around at the victim at welt raising speed.

Hit the return on the reel to bring back the towel, stuff the weight back into the cannon, and select your next victim.

Of course this will take a little practice to get the range right and you may cause some concussions in the process with the weight arrangement, but it will be worth it. It's for science and the domination of the pool side and the locker room.

Answer 8

I see two mayor problems with your request (please bear in mind I'm not a scientist and I'm not an English native, I may explain quite badbly... sorry about that).

A) When a projectile whipslaps, it basically kills off a lot of rotation. Space satellites "play yoyo" with dispensable whipslaping parts as a means to stop rotating (https://en.wikipedia.org/wiki/Yo-yo_de-spin). So, your projectile has to whipslap just the right moment, because it will have no energy for a second try.

B) the towel is a non-newtonian object. It's not rigid, it's not solid, and in fact its center of gravity isn't "fixed" in a certain point, since it's a moving fabric and air will effect it in the air.

So, bad news. You need micro miniaturizing...

1) A device to "make it whipslap" at the right distance to target. 2) A way to detonate the whipslap itself.

Antiair rounds in WW2 used a doppler sensing radio device, but that was a shell thrown to a solid object. Maybe a solid core with the towel wrapped around, tied by a cord joining the towel back to the weapon? Throwing the towel as a fabric envolving a rotating axle-like core linked back to a brake back in the weapon? You shoot, the piece rotates "winding up" the towel, cuts rotation when a doppler sensing antenna in the axle notices a solid mass at the right distance and makes the thing to whipslap by inertia.

Could work, but the problem is, the projectile will be rotating in an axis 90° opposite what you need for an stable projectile. It will not stay pointing the right direction. AND projectile tied to the weapon means the shooter will get pulled by the thing when it detonates.

So, to sum up... hard to detonate at the right time, hard to aim, short range, single shoot, bulky as hell, will pull the shooter. Not an easy thing, you know. Not at all... I'll say "possible but unpractical".