propellant

[gypsyman]

Traded for a spudzooka years ago. Don't take it out and play with it as much as I use to. A friend of mine told me that Aqua Net hair spray gives the best power. It's the only thing I ever used. Does anybody hear have a better suggestion? I know I shot a chunk of potatoe over a neighbors pole barn, when he was on the roof. And it's a good 225yds across the field. Thanks for any help! gypsyman

[tapwater]

   Well, Gypsy, I'm still using Agua Net when I (rarely) take the thing out.
It's sticky and messy, but I can't complain about the results. When the
weather warms up, I want to try ether again. Getting the fuel-air mix
correct is all trial and error.
   If you haven't, look at chipmunk's thread.."Beat That". His propane
metering system is similar to those sold on the net. Simple and practical.

[chipmunk]

In my opinion, here they are listed weakest to strongest of the common propellants:

Aqua Net, Ether, Propane


For most people, I'd suggest ether.  Get a can and use it just like the Aqua Net.  It's got a bit more power plus it doesn't gum up the chamber quite like Aqua Net.  It seems just as easy to ignite as the Aqua Net too.   I tried both when I first started out and have never used Aqua Net again.

If you really want to get serious, look into my propane system as tapwater mentioned.  It is a bit more work and it can be hard to get it to ignite consistently, but once you get it right it will give about 50% more distance.  (At least it has for me)

WARNING  - DO NOT TRY THIS IN A PVC GUN...IN FACT...DO NOT EVER TRY THIS!!!
I once knew a guy who built one out of some steel parts he had laying around.  The proportions (chamber to barrel) were off so he could only manage about 100 yards with ether.  In frustration he started using pure oxygen plumbed into the chamber.   Suddenly he was getting 400 yards out of a potato.   We've kinda drifted apart since then but as far as I know it never exploded or anything.  I'd still never try it myself.   Not even in a solid steel piece like that.  Oxygen is dangerous.
AGAIN - WARNING - DO NOT TRY THIS IN A PVC GUN...IN FACT...DO NOT EVER TRY THIS!!!

[Victor3]

 The cleanest setup I made when I was playing with them was with butane from a lighter refill can.

 On the back of the chamber, I installed a brass schrader (tire) valve with a hole drilled in the cap to accept the plastic tip of the butane can. I would put the tip into the hole in the valve cap and tap the base of the can with the heel of my hand, opening both the tire valve and the valve on the can at the same time to charge the gun (I drilled a teeny hole near the end of the plastic tip so gas would flow easily out of the can). The original gasket under the cap of the tire valve sealed perfectly around the plastic fill tube on the butane can, so gas couldn't escape.

 I also installed a capped brass fitting in the chamber so I could take the cap off and blow into the muzzle to clear the chamber for the next shot. That way I didn't have to remove the large 'cleanout' plug from the rear of the chamber after each shot.

[tapwater]

   I feel the need to reiterate what munk said about using oxygen. Also, don't even think about
acetylene. A friend of mine was playing with that mixture and luckily, only the igniter blew out of its'
mount, giving him minor hand burns.

   In my mis-spent youth, we'd fill garbage bags with oxy-acetylene mix and let them drift into a
bonfire. It made a great, chest thumping boom.....until a bag exploded while filling it. The mix is
very sensitive to static electricity. (think about how a garbage bag clings to you)
It blew my co-worker's shirt buttons off, ignited the torch and ruined our hearing for a few days.

      Please....Do not mess with oxy or acetylene.

[chipmunk]

If we are on the subject of warning people...

Hydrogen's a deadly one too.   Doubt many people would have easy access to it but if you do, don't even think about it.   I have a story on that one but I probably don't want this one on the net

[tapwater]

   Is hydrogen sensitive also? I used to make my own in small amounts. There are a couple easy methods.
I'd fill toy balloons, and as they rose, toss a wooden match at them. Nice boom and fireball. Sometimes, I'd let them gain some altitude and shoot them with a .22 tracer. It worked sometimes, but not always.

[chipmunk]

It's kinda like gasoline in that it sometimes won't burn when you're trying to light it but can commonly go off without you expecting it.  The difference is that it is WAY more powerful then gasoline or really anything else I've played with.   Put it in a confined space and add some static electricity and you have a terrifying blast!

[rickt300]

I've used right gaurd spray deoderant in my spud gun.

[Hunter Fishman]

I worked at a pipe & supply landscape store & 1 time had nothing but PVC purple primer to use. You can get several shots out of a good swabbing but it softens the pipe & is messy. I swabbed mine one time & had to hide it from my boss,then remembered it 2 days later in summer weather,couldnt get the cap off to re swab so I just hit the igniter & to my surprise it fired from fumes built up from the heat! Even more hilarious It accidently fired a pvc rocket at my bosses son. I made pvc mortars/ rockets instead of wasting fruit & vegitables. They work better!

[thinwater]

I fired my spud gun today with my acetiline/oxy tourch set but did not put any potato in it because I was afraid of the extra power blowing it up. I am glad I did not put a potato in it, it was LOUD. My son came running out to see what blew up. I won't be doing that again. It was like a carbide cannon, loud but did not shoot anything.

[Hunter Fishman]

I fired my spud gun today with my acetiline/oxy tourch set but did not put any potato in it because I was afraid of the extra power blowing it up. I am glad I did not put a potato in it, it was LOUD. My son came running out to see what blew up. I won't be doing that again. It was like a carbide cannon, loud but did not shoot anything.

If you wanted to blow out all the windows within a city block you fill up one of those BIG punch baloons with helium & a regular sized baloon with oxegen/setaline,Tie the small baloon under the big one, then tie on a loooonnnnggg string & I MEAN LONG! soak it in a slow burning liquid
(I used keresene) let it fly as high as you can get it before you lite it cus 200-400 ft is low enough to blow out every window around! My friends & I learned the hard way!