Common Fuels for Combustion Spudguns - Revision history

Jimmy101 at 17:18, 26 September 2015

2015-09-26T17:18:18Z

← Older revision		Revision as of 12:18, 26 September 2015
Line 610:		Line 610:
	[http://www.burntlatke.com/lpmapprussets.html]) comparing the		[http://www.burntlatke.com/lpmapprussets.html]) comparing the
	muzzle velocities of propane and		muzzle velocities of propane and
	MAPP~~</a>~~. Using a 1.5"D riffled barrel shooting spuds, Latke found that		MAPP. Using a 1.5"D riffled barrel shooting spuds, Latke found that
	MAPP out performed propane with		MAPP out performed propane with
	muzzle velocities of 444 (+/-34) FPS for MAPP and 398 (+/-34) FPS for		muzzle velocities of 444 (+/-34) FPS for MAPP and 398 (+/-34) FPS for

Jimmy101: /* Common Fuels for Combustion Spud Guns */

2011-02-21T00:31:26Z

Common Fuels for Combustion Spud Guns

← Older revision		Revision as of 19:31, 20 February 2011
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	fairly irrelevant since the shot to shot reproducibility is so poor. It		fairly irrelevant since the shot to shot reproducibility is so poor. It
	really doesn't matter, with this type of fuel, whether the predicted		really doesn't matter, with this type of fuel, whether the predicted
	[[muzzle velocity]] is 10% ~~great~~ with one fuel		[[muzzle velocity]] is 10% greater with one fuel
	versus another since the shot to shot variability is probably more like		versus another since the shot to shot variability is probably more like
	50%. (Even with precisely metered propane,		50%. (Even with precisely metered propane,

Jimmy101: Undo revision 4244 by 83.234.245.140 (Talk)

2010-12-05T17:44:45Z

Undo revision 4244 by 83.234.245.140 (Talk)

Show changes

83.234.245.140: CLICK HERE TO ENTER DRUGSTORE

2010-12-05T07:03:51Z

CLICK HERE TO ENTER DRUGSTORE

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Jimmy101: Fixed percentages for butane (was 3.67% and 3.81%)

2009-09-30T17:39:27Z

Fixed percentages for butane (was 3.67% and 3.81%)

GalFisk: H20 -> H2O

2009-08-13T21:29:07Z

H20 -> H2O

← Older revision		Revision as of 16:29, 13 August 2009
Line 20:		Line 20:

	The stoichiometry is determined by the fuel you are using. For example, the balanced chemical equation for the complete combustion of propane (C<sub>3</sub>H<sub>8</sub>) in air (~21% oxygen, O<sub>2</sub>) is;		The stoichiometry is determined by the fuel you are using. For example, the balanced chemical equation for the complete combustion of propane (C<sub>3</sub>H<sub>8</sub>) in air (~21% oxygen, O<sub>2</sub>) is;
	C<sub>3</sub>H<sub>8</sub> + 5O<sub>2</sub> = 3CO<sub>2</sub> + 4H<sub>2</sub>0		C<sub>3</sub>H<sub>8</sub> + 5O<sub>2</sub> = 3CO<sub>2</sub> + 4H<sub>2</sub>O

	For every molecule of propane we need 5 molecules of oxygen. Combustion produces 3 molecules of carbon dioxide (CO<sub>2</sub>) and 4 molecules of water. Gases have the handy property that the number of molecules is proportional to the volume at a constant [[pressure]] so the volume ratio of fuel to air will be the same as the ratio of molecules. Since air is only ~21% oxygen we can calculate that for every unit of volume of the chamber we need (1C<sub>3</sub>H<sub>8</sub>/5O<sub>2</sub>)*(0.21) = 0.042 volumes of fuel. 0.042 volumes of fuel is the same as 4.2% of fuel. (There are some subtleties about calculating the actual volume percent that'll be discussed below.)		For every molecule of propane we need 5 molecules of oxygen. Combustion produces 3 molecules of carbon dioxide (CO<sub>2</sub>) and 4 molecules of water. Gases have the handy property that the number of molecules is proportional to the volume at a constant [[pressure]] so the volume ratio of fuel to air will be the same as the ratio of molecules. Since air is only ~21% oxygen we can calculate that for every unit of volume of the chamber we need (1C<sub>3</sub>H<sub>8</sub>/5O<sub>2</sub>)*(0.21) = 0.042 volumes of fuel. 0.042 volumes of fuel is the same as 4.2% of fuel. (There are some subtleties about calculating the actual volume percent that'll be discussed below.)
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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> 2H<sub>2</sub> +		face="Helvetica, Arial, sans-serif" size="-1"><small> 2H<sub>2</sub> +
	O<sub>2</sub> = 2H<sub>2</sub>0</small></font></small></td>		O<sub>2</sub> = 2H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> CH<sub>4</sub> +		face="Helvetica, Arial, sans-serif" size="-1"><small> CH<sub>4</sub> +
	2O<sub>2</sub> = CO<sub>2</sub> + 2H<sub>2</sub>0</small></font></small></td>		2O<sub>2</sub> = CO<sub>2</sub> + 2H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> 2C<sub>2</sub>H<sub>6</sub>		face="Helvetica, Arial, sans-serif" size="-1"><small> 2C<sub>2</sub>H<sub>6</sub>
	+ 7O<sub>2</sub> = 4CO<sub>2</sub> + 6H<sub>2</sub>0</small></font></small></td>		+ 7O<sub>2</sub> = 4CO<sub>2</sub> + 6H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>2</sub>H<sub>4</sub>		face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>2</sub>H<sub>4</sub>
	+ 3O<sub>2</sub> = 2CO<sub>2</sub> + 2H<sub>2</sub>0</small></font></small></td>		+ 3O<sub>2</sub> = 2CO<sub>2</sub> + 2H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> 2C<sub>2</sub>H<sub>2</sub>		face="Helvetica, Arial, sans-serif" size="-1"><small> 2C<sub>2</sub>H<sub>2</sub>
	+ 5O<sub>2</sub> = 4CO<sub>2</sub> + 2H<sub>2</sub>0</small></font></small></td>		+ 5O<sub>2</sub> = 4CO<sub>2</sub> + 2H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>3</sub>H<sub>8</sub>		face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>3</sub>H<sub>8</sub>
	+ 5O<sub>2</sub> = 3CO<sub>2</sub> + 4H<sub>2</sub>0</small></font></small></td>		+ 5O<sub>2</sub> = 3CO<sub>2</sub> + 4H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> 2C<sub>4</sub>H<sub>10</sub>		face="Helvetica, Arial, sans-serif" size="-1"><small> 2C<sub>4</sub>H<sub>10</sub>
	+ 13O<sub>2 </sub>= 8CO<sub>2</sub> + 10H<sub>2</sub>0</small></font></small></td>		+ 13O<sub>2 </sub>= 8CO<sub>2</sub> + 10H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> 2C<sub>4</sub>H<sub>10</sub>		face="Helvetica, Arial, sans-serif" size="-1"><small> 2C<sub>4</sub>H<sub>10</sub>
	+ 13O<sub>2 </sub>= 8CO<sub>2</sub> + 10H<sub>2</sub>0</small></font></small></td>		+ 13O<sub>2 </sub>= 8CO<sub>2</sub> + 10H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" bgcolor="#dddddd" nowrap="nowrap" valign="middle"><small><font		<td align="left" bgcolor="#dddddd" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>3</sub>H<sub>4</sub>		face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>3</sub>H<sub>4</sub>
	+ 4O<sub>2</sub> = 3CO<sub>2</sub> + 2H<sub>2</sub>0</small></font></small></td>		+ 4O<sub>2</sub> = 3CO<sub>2</sub> + 2H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="left" bgcolor="#dddddd" nowrap="nowrap" valign="middle"><small><font		<td align="left" bgcolor="#dddddd" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>3</sub>H<sub>4</sub>		face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>3</sub>H<sub>4</sub>
	+ 4O<sub>2</sub> = 3CO<sub>2</sub> + 2H<sub>2</sub>0</small></font></small></td>		+ 4O<sub>2</sub> = 3CO<sub>2</sub> + 2H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>

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	<td align="left" nowrap="nowrap" valign="middle"><small><font		<td align="left" nowrap="nowrap" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>4</sub>H<sub>10</sub>O		face="Helvetica, Arial, sans-serif" size="-1"><small> C<sub>4</sub>H<sub>10</sub>O
	+ 6O<sub>2 </sub>= 4CO<sub>2 </sub>+ 5H<sub>2</sub>0</small></font></small></td>		+ 6O<sub>2 </sub>= 4CO<sub>2 </sub>+ 5H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	<tr>		<tr>
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	<td align="center" valign="middle"><small><font		<td align="center" valign="middle"><small><font
	face="Helvetica, Arial, sans-serif" size="-1"><small>C<sub>2</sub>H<sub>6</sub>O		face="Helvetica, Arial, sans-serif" size="-1"><small>C<sub>2</sub>H<sub>6</sub>O
	+ 3O<sub>2 </sub>= 2CO<sub>2 </sub>+ 3H<sub>2</sub>0</small></font></small></td>		+ 3O<sub>2 </sub>= 2CO<sub>2 </sub>+ 3H<sub>2</sub>O</small></font></small></td>
	</tr>		</tr>
	</table>		</table>

Jimmy101: Added MAP/Pro (propylene)

2009-08-07T22:09:45Z

Added MAP/Pro (propylene)

@@ Line 376: / Line 376: @@
 + 4O<sub>2</sub> = 3CO<sub>2</sub> + 2H<sub>2</sub>0</small></font></small></td>
 </tr>
 <tr>
 <td align="center" valign="middle"><font
@@ Line 430: / Line 456: @@
 <li>MAPP gas is a proprietary mixture of various hydrocarbons,
 principally methyl acetylene, propadiene and propane.</li>
-<li>References: http://members.nuvox.net/F%7Eon.jwclymer/Frq/Fhoctable.html<br>
+<li>MAP/Pro gas is a proprietary mixture of propylene and 0.5% propane.</li>
 http://members.nuvox.net/F~on.jwclymer/Frq/Fhoctable.html<br>
 http://home.fuse.net/clymer/rq  combustion calculator<br>
 http://www.nrc.gov/freading-rm/fdoc-collections/fnuregs/fstaff/fsr1805/ffinal-report/f15_explosion_calculations.xls
-</li>
 <h2>"Traditional" Fuels</h2>
 <h3>RightGuard</h3>

Jimmy101: Added combustion limits for dimethyl ether

2009-02-03T18:55:10Z

Added combustion limits for dimethyl ether

← Older revision		Revision as of 13:55, 3 February 2009
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	<td align="center" valign="middle"><font color="#cc0000"><font		<td align="center" valign="middle"><font color="#cc0000"><font
	size="-1"><font face="Helvetica, Arial, sans-serif"><b>329</b></font></font></font></td>		size="-1"><font face="Helvetica, Arial, sans-serif"><b>329</b></font></font></font></td>
	<td align="center" valign="middle"> ~~<br>~~		<td align="center" valign="middle">3.0 - 18.6</td>
	</td>
	<td align="center" valign="middle"><font		<td align="center" valign="middle"><font
	face="Helvetica, Arial, sans-serif" size="-1">-25<br>		face="Helvetica, Arial, sans-serif" size="-1">-25<br>

Jimmy101: fixed the muzzle velocity link ,changed PVC cleaner to PVC primer

2008-06-04T17:11:33Z

fixed the muzzle velocity link ,changed PVC cleaner to PVC primer

← Older revision		Revision as of 12:11, 4 June 2008
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	fairly irrelevant since the shot to shot reproducibility is so poor. It		fairly irrelevant since the shot to shot reproducibility is so poor. It
	really doesn't matter, with this type of fuel, whether the predicted		really doesn't matter, with this type of fuel, whether the predicted
	[[muzzle		[[muzzle velocity]] is 10% great with one fuel
	velocity]] is 10% great with one fuel
	versus another since the shot to shot variability is probably more like		versus another since the shot to shot variability is probably more like
	50%. (Even with precisely metered propane,		50%. (Even with precisely metered propane,
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	<p>One thing that you should keep in mind with liquid fuels is the		<p>One thing that you should keep in mind with liquid fuels is the
	potential for weakening the PVC. Take a look at the ingredients list on		potential for weakening the PVC. Take a look at the ingredients list on
	your cans of PVC ~~cleaner~~ and [[PVC Glue\|glue]]. Anything listed on those cans should		your cans of PVC [[primer]] and [[PVC Glue\|glue]]. Anything listed on those cans should
	probably be avoided as fuels. Acetone and tetrahydrofuran (THF) in		probably be avoided as fuels. Acetone and tetrahydrofuran (THF) in
	particular are probably not the best idea for fuel since they soften		particular are probably not the best idea for fuel since they soften
	PVC.</p>		PVC.</p>

	<h2>Other Factors</h2>		<h2>Other Factors</h2>
	The heat of combustion is not the only factor affecting the power of a		The heat of combustion is not the only factor affecting the power of a

Benstern: added links

2008-06-04T06:37:27Z

added links

← Older revision		Revision as of 12:39, 30 September 2009
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	face="Helvetica, Arial, sans-serif" size="-1">105</font></b></td>		face="Helvetica, Arial, sans-serif" size="-1">105</font></b></td>
	<td align="center" valign="middle"><font		<td align="center" valign="middle"><font
	face="Helvetica, Arial, sans-serif" size="-1">3.67</font></td>		face="Helvetica, Arial, sans-serif" size="-1">3.12</font></td>
	<td align="center" valign="middle"><font		<td align="center" valign="middle"><font
	face="Helvetica, Arial, sans-serif" size="-1">3.81</font></td>		face="Helvetica, Arial, sans-serif" size="-1">3.22</font></td>
	<td align="center" valign="middle"><font		<td align="center" valign="middle"><font
	face="Helvetica, Arial, sans-serif" size="-1">58</font></td>		face="Helvetica, Arial, sans-serif" size="-1">58</font></td>
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	face="Helvetica, Arial, sans-serif" size="-1">105</font></b></td>		face="Helvetica, Arial, sans-serif" size="-1">105</font></b></td>
	<td align="center" valign="middle"><font		<td align="center" valign="middle"><font
	face="Helvetica, Arial, sans-serif" size="-1">3.67</font></td>		face="Helvetica, Arial, sans-serif" size="-1">3.12</font></td>
	<td align="center" valign="middle"><font		<td align="center" valign="middle"><font
	face="Helvetica, Arial, sans-serif" size="-1">3.81</font></td>		face="Helvetica, Arial, sans-serif" size="-1">3.22</font></td>
	<td align="center" valign="middle"><font		<td align="center" valign="middle"><font
	face="Helvetica, Arial, sans-serif" size="-1">58</font></td>		face="Helvetica, Arial, sans-serif" size="-1">58</font></td>

← Older revision		Revision as of 01:37, 4 June 2008
Line 1:		Line 1:
	<p>So, you've glued together some hunks of PVC, installed an ignition		<p>So, you've glued together some hunks of PVC, installed an [[Ignition source\|ignition
	system and bought a bag of russets. What should you use for fuel to get		system]] and bought a bag of [[potato\|russets]]. What should you use for [[fuel]] to get
	the most oomph into		the most oomph into
	that hunk of starch? There are many ways to judge the best fuel for a		that hunk of starch? There are many ways to judge the best fuel for a
	combustion spud gun. How		[[Combustion cannon\|combustion spud gun]]. How
	easy is it to use? How expensive is it? And, perhaps most important to		easy is it to use? How expensive is it? And, perhaps most important to
	the average spudder, which fuel		the average spudder, which fuel
Line 13:		Line 13:
	'''You Must Use The Correct Amount Of Fuel'''.		'''You Must Use The Correct Amount Of Fuel'''.

	An inexperienced spud gunner might think that adding more fuel to the chamber will increase the power of their gun. This is almost always incorrect. For all common fuels too much fuel won't ignite. All fuels have a property called the "combustion limits". The combustion limits is the range of fuel concentration (usually expressed as the volume percent of fuel in the chamber) that will actually ignite. For most hydrocarbon fuels (propane, butane, flammable ~~aerosols~~ etc.) the combustion limits is about 3% to 9% by volume. If you inject less than ~3%, or more than ~9% of the chamber volume in fuel then the gun will not ignite.		An inexperienced spud gunner might think that adding more fuel to the [[chamber]] will increase the power of their gun. This is almost always incorrect. For all common fuels too much fuel won't ignite. All fuels have a property called the "combustion limits". The combustion limits is the range of fuel concentration (usually expressed as the volume percent of fuel in the chamber) that will actually ignite. For most hydrocarbon fuels ([[propane]], [[butane]], flammable [[aerosol]]s etc.) the combustion limits is about 3% to 9% by volume. If you inject less than ~3%, or more than ~9% of the chamber volume in fuel then the gun will not ignite.

	'''If you've built a combustion spudgun and you can't get it to fire the most likely problem is that you are using too much fuel.'''		'''If you've built a combustion spudgun and you can't get it to fire the most likely problem is that you are using too much fuel.'''

	So, your first challenge is to get your fuel in the 3~9% range so that the gun will fire. Your second challenge is to try to get the fuel as close as possible to the '''stoichiometric''' fuel ratio. The stoichiometric fuel ratio is the ratio of fuel to oxygen that allows all the fuel to burn and leaves no oxygen left over at the end of combustion. The stoichiometric fuel ratio will get you very close to the maximum power the fuel is capable of.		So, your first challenge is to get your fuel in the 3~9% range so that the gun will fire. Your second challenge is to try to get the fuel as close as possible to the '''stoichiometric''' fuel ratio. The [[Stoichiometry\|stoichiometric]] fuel ratio is the ratio of fuel to oxygen that allows all the fuel to burn and leaves no oxygen left over at the end of [[Combustion process\|combustion]]. The stoichiometric fuel ratio will get you very close to the maximum power the fuel is capable of.

	The stoichiometry is determined by the fuel you are using. For example, the balanced chemical equation for the complete combustion of propane (C<sub>3</sub>H<sub>8</sub>) in air (~21% oxygen, O<sub>2</sub>) is;		The stoichiometry is determined by the fuel you are using. For example, the balanced chemical equation for the complete combustion of propane (C<sub>3</sub>H<sub>8</sub>) in air (~21% oxygen, O<sub>2</sub>) is;
	C<sub>3</sub>H<sub>8</sub> + 5O<sub>2</sub> = 3CO<sub>2</sub> + 4H<sub>2</sub>0		C<sub>3</sub>H<sub>8</sub> + 5O<sub>2</sub> = 3CO<sub>2</sub> + 4H<sub>2</sub>0

	For every molecule of propane we need 5 molecules of oxygen. Combustion produces 3 molecules of carbon dioxide (CO<sub>2</sub>) and 4 molecules of water. Gases have the handy property that the number of molecules is proportional to the volume at a constant pressure so the volume ratio of fuel to air will be the same as the ratio of molecules. Since air is only ~21% oxygen we can calculate that for every unit of volume of the chamber we need (1C<sub>3</sub>H<sub>8</sub>/5O<sub>2</sub>)*(0.21) = 0.042 volumes of fuel. 0.042 volumes of fuel is the same as 4.2% of fuel. (There are some subtleties about calculating the actual volume percent that'll be discussed below.)		For every molecule of propane we need 5 molecules of oxygen. Combustion produces 3 molecules of carbon dioxide (CO<sub>2</sub>) and 4 molecules of water. Gases have the handy property that the number of molecules is proportional to the volume at a constant [[pressure]] so the volume ratio of fuel to air will be the same as the ratio of molecules. Since air is only ~21% oxygen we can calculate that for every unit of volume of the chamber we need (1C<sub>3</sub>H<sub>8</sub>/5O<sub>2</sub>)*(0.21) = 0.042 volumes of fuel. 0.042 volumes of fuel is the same as 4.2% of fuel. (There are some subtleties about calculating the actual volume percent that'll be discussed below.)

	=Common Fuels for Combustion Spud Guns=		=Common Fuels for Combustion Spud Guns=
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	Percent" gives the amount of fuel		Percent" gives the amount of fuel
	required when the fuel does not		required when the fuel does not
	displace air from the chamber, for example when using a pressurized		displace air from the chamber, for example when using a [[Fuel meter\|pressurized
	meter system. <br>		meter system]]. <br>
	<br>		<br>
	The key value for comparing two fuels based on their heats of		The key value for comparing two fuels based on their heats of
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	difference between the various fuels based on their "Heat per mole		difference between the various fuels based on their "Heat per mole
	Oxygen" values. The only two fuels with significantly higher values are		Oxygen" values. The only two fuels with significantly higher values are
	hydrogen and acetylene, both of		hydrogen and [[acetylene]], both of
	which give 10~15% more energy		which give 10~15% more energy
	than the other fuels.		than the other fuels.
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	<tr>		<tr>
	<td align="left" bgcolor="#dddddd" valign="middle"><font		<td align="left" bgcolor="#dddddd" valign="middle"><font
	face="Helvetica, Arial, sans-serif" size="-1"><b> MAPP</b><sup>(2)</sup></font></td>		face="Helvetica, Arial, sans-serif" size="-1"><b> [[MAPP]]</b><sup>(2)</sup></font></td>
	<td bgcolor="#dddddd"><br>		<td bgcolor="#dddddd"><br>
	</td>		</td>
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	which may or may not be flammable, probably constitute a fairly low		which may or may not be flammable, probably constitute a fairly low
	percentage of the gas. There is the possibility that the other		percentage of the gas. There is the possibility that the other
	ingredients may gum up the spark gap, fan or cleanout plug threads		ingredients may gum up the [[spark gap]], [[Chamber fan\|fan]] or cleanout plug threads
	after several uses.		after several uses.
	<h3>Starter Fluid</h3>		<h3>Starter Fluid</h3>
	<p>By definition, automotive starter fluid is combustible. There are no		<p>By definition, automotive [[Starting fluid\|starter fluid]] is combustible. There are no
	doubt a couple of different formulations. One common formulation		doubt a couple of different formulations. One common formulation
	includes 10~30% (weight) dimethyl ether and a propane propellant. Most		includes 10~30% (weight) dimethyl ether and a propane propellant. Most
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	fairly irrelevant since the shot to shot reproducibility is so poor. It		fairly irrelevant since the shot to shot reproducibility is so poor. It
	really doesn't matter, with this type of fuel, whether the predicted		really doesn't matter, with this type of fuel, whether the predicted
	muzzle		[[muzzle
	velocity is 10% great with one fuel		velocity]] is 10% great with one fuel
	versus another since the shot to shot variability is probably more like		versus another since the shot to shot variability is probably more like
	50%. (Even with precisely metered propane,		50%. (Even with precisely metered propane,
	the shot to shot variability in muzzle velocity for shooting spuds is		the shot to shot variability in muzzle velocity for shooting [[potato\|spuds]] is
	typically in the 10 to 20% range.)</p>		typically in the 10 to 20% range.)</p>
	<p>One thing that you should keep in mind with liquid fuels is the		<p>One thing that you should keep in mind with liquid fuels is the
	potential for weakening the PVC. Take a look at the ingredients list on		potential for weakening the PVC. Take a look at the ingredients list on
	your cans of PVC cleaner and glue. Anything listed on those cans should		your cans of PVC cleaner and [[PVC Glue\|glue]]. Anything listed on those cans should
	probably be avoided as fuels. Acetone and tetrahydrofuran (THF) in		probably be avoided as fuels. Acetone and tetrahydrofuran (THF) in
	particular are probably not the best idea for fuel since they soften		particular are probably not the best idea for fuel since they soften
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	shot variation in velocity that the relatively small difference between		shot variation in velocity that the relatively small difference between
	fuels is not particularly relevant. Latke ([http://www.burntlatke.com/]), as good of a spudder as		fuels is not particularly relevant. Latke ([http://www.burntlatke.com/]), as good of a spudder as
	there is, has done several studies using an accurate chronometer to		there is, has done several studies using an accurate [[chronometer]] to
	measure muzzle velocities. In all of his studies with spuds as		measure muzzle velocities. In all of his studies with spuds as
	projectiles, using precisely metered fuels, the shot to shot		projectiles, using precisely metered fuels, the shot to shot