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Unread postPosted: Mon Jan 31, 2005 12:22 am
Author: PCGUY
<div align="center">SPAC 1

Provided By Fiebig - <a href=""></a>

This is the SPAC1. It is a very simple steam powered spud gun I assembled from parts I had left over from various projects. Basically it's a pneumatic mini, and for its size, it's very powerful. The chamber is a 1/2" x 4" galvanized nipple. On the rear end is an end cap, on the opposite end is a 1/2" ball valve. From the ball valve there is a 1/2" to 1/4" bushing. Then comes the barrel, a piece of 1/4" pipe 11" long.

How the SPAC1 works:

The ball valve is opened and water is poured down the barrel into the chamber. I usually use about 2-3 tablespoons of tap water.

Ball valve is closed, ammo is but into the barrel, and the entire gun is put into vice grips

After about 2 or 3 minutes, the water (or at least most of it) has boiled inside the chamber creating a butt load of high pressure steam! Boiling the water really takes longer than it should, because the chamber is galvanized steel it doesn't heat up as fast as possible. If the chamber were copper the water would boil much faster.

The gun is picked up with the vice grips (since holding 200 degree metal pipe with your hands isn't pleasant) and the ball valve is quickly opened releasing all of the steam and launching the projectile!

Here is a video of the SPAC1 launching the screw at a block of styrofoam. I know its just styrofoam, but for a cannon this size, being able to lodge a screw 2 inches into a solid block of styrofoam and send it flying back 10 feet is pretty good.

For the video please visit
<a href=""></a>
Provided By Fiebig - <a href=""></a></div>

Unread postPosted: Mon Jan 31, 2005 3:23 pm
Author: syco kilaa
thats a good amount of power ful such a small cannon, I think that if you used, copper, like you said that it would indeed heat up a lot faster, plus you could probably make a bigger chamber and get higher pressures.

Unread postPosted: Mon Jan 31, 2005 6:47 pm
Author: theexp
that thing is really cool, but it suxs how you have no way of holding it. I think i am going to make one, that is pretty cool. I like how it is so simple but cool. You should make one out of copper. wait, how would you hold the copper welds together? or would it be threaded, not soldered?
BUt awsome gun

Unread postPosted: Mon Jan 31, 2005 9:52 pm
Author: BC Pneumatics
As long as you dont hea it enough to sofen the solder it would be fine. Also solder is harder to melt a second time than it is the first.

Unread postPosted: Tue Feb 01, 2005 9:02 am
Author: theexp
ok, that would explain alot, but if i make one, should i solder it or have it threaded

Unread postPosted: Wed Feb 02, 2005 3:55 pm
Author: syco kilaa
I think that you should probably thread it all together even though you probably can't find threaded copper pipe anywhere.

Unread postPosted: Wed Feb 02, 2005 5:07 pm
Author: theexp
true, but don't they have threading machines, at your lowes,

Wiat the walls of the copper would probalbly be to thin.. right?

Unread postPosted: Sat Nov 12, 2005 4:30 am
Author: deathtodeer666
copper pipe can be threaded but it would be to thin to seal with high presure but Im pretty sure the solder will melt if heated to boil water.

Unread postPosted: Sat Nov 12, 2005 12:22 pm
Author: Animal81182
you can buy commpression fittings which would do the job they slide over the pipe with an olive (Brass 'o' ring) and tighten up using a pair of stilsons - all fittings are standard and can have threaded ends simple to use

OH off topic but i cant seem to keep myself logged in everytime i click a post or other page on the site i am automatically logged out it is damn annoying it aint happened to me before????


Unread postPosted: Sat Nov 12, 2005 12:56 pm
Author: CS
Then your problem would be the o ring melting. JB Weld?
I had that problem a while back and it was super frusterating. This weird but for I use a W XP and the username you signed up under you have to use or you will have the same problem (not sure why but it worked for me) Also there is something you can do with the cookies but Im not real sure how you do it (a-hum BLB or PC) This is obviously not the right question to ask here for future reference though just PM PCGUY.

Unread postPosted: Sun Dec 04, 2005 3:27 pm
Author: pyromanic13
hey I made sorta the same gun but instead of boiling water use dry ice it works 100x better

Unread postPosted: Mon Jan 09, 2006 5:09 pm
Author: cardinals08
I dont think the solder would melt, I just installed a water softener with my dad, and we tried melting the solder instead of cutting the copper pipe, and it wouldn't melt but you could here the water boiling like crazy inside. also, you could heat it in the middle of the pipe, not where you soldered, and might be less likely to melt because of indirect heat, the ends wouldnt get as hot but would boil water still

Unread postPosted: Mon Jan 09, 2006 10:13 pm
Author: Mini Khan
try dry ice and water i heard u can get it up to 900 psi by that, be carful

Unread postPosted: Sun Oct 01, 2006 4:21 pm
Author: brian Casey
sweet gun i would never think to make a steam powered gun alot more dangerous thought if you arent carefull with it your should mount a digital thermomerter to it also that could be preety cool

Unread postPosted: Tue Oct 31, 2006 6:50 pm
Author: kris
tested on myth busters