Of All The Tools We Bring along on the trail, there's really only one that can help save the entire vehicle, and that's the fire extinguisher. Most everybody carries an extinguisher, but often that's only because nearly every organized run requires it. Little, if any, thought is given to an extinguisher's actual effectiveness-if the gauge registers in the green zone and it gets us through the safety inspection, life is good.
Yes, life is good. We have 4x4s and trails to drive on with our friends. There's the occasional breakdown and stuck that adds to the fun and camaraderie, and for the most part everybody has the tools, winches, parts, and know-how to get going again. With one notable exception: a fire. Chances are that several people will come running with their extinguishers only to find that they don't work. Dry chemical extinguishers' media can compact inside when subjected to vibrations, whether it's mounted upright or on its side, and let's face it: Trail rides have a few bumps along the way. After a few years in the vehicle the extinguisher may well be useless. This is one of the reasons these extinguishers are supposed to be inspected every year in commercial buildings, even when just hanging on a wall. It's a good idea to bonk a dry chemical extinguisher against a tire, tree, or something a few times before attempting to use it.
Fire extinguishers come in several varieties and sizes. Pictured to the left is H3R's HalGuard (No. HG250R) which is a 2.5-pound clean agent unit with a UL rating of 2 B,C, meaning that it's effective on flammable liquids and electrical fires but isn't all that good for trash and wood. On the right is a 1-pound MaxOut (No. MX100C) from H3R containing dry chemicals, also rated 2 B, C. With both equally effective-at least in theory-on class B and C fires, and with the chromed MaxOut costing approximately half of the $120 that the larger HalGuard fetches, it could be a wash as to which one to choose. At least until you had to clean up the aftermath of using dry chemicals, which may still be far better than the result of an uninhibited fire. Either way, do get a good fire extinguisher now, and remember that bigger is better with any kind of extinguisher.
An Alternative To The Powder Room
Gases don't clump, and that's one reason extinguishers come with halon and other so-called clean agents. Unlike dry chemicals, clean agents are, well, clean. Halon has been the medium of choice for putting out fires in aircraft, computers, and other sensitive and expensive equipment, but it's getting pricey and harder to come by. H3R Performance has been a source for halon extinguishers for years, but with dwindling supplies it recently introduced HalGuard as a less expensive, yet highly effective alternative available in 1-pound through 15.5-pound bottles. Expect a 6- to 10-foot effective range from a 2.5-pound HalGuard extinguisher.
With halon becoming unobtainium, H3R has released the MaxOut line of extinguishers, but these use a dry chemical. They use siliconized sodium bicarbonate based chemicals in the 1-pounders and fluidized, siliconized mono ammonium phosphate in the larger, Coast Guard-approved size. You may want to keep one of these in your garage or trailer as they are more effective than the cleaner HalGuard when dealing with wood or paper fires. A 1-pounder will work at 5 to 8 feet, while the 2.5-pound units will go 9 to 15 feet.
Both gas and dry-chemical versions have their strong points and both starve a fire by changing the reaction between the heat, oxygen, and fuel. Dry chemicals such as the MaxOut are often more effective per pound and let you see exactly where the agent is going. In contrast, the HalGuard doesn't leave a mess, but can be trickier to use in windy conditions since you can't readily see where the agent ends up-granted, that is not an issue with underhood and interior fires. Both kinds can be had in a chrome or red bottle and are nonconductive, which could be quite valuable in case you end up spraying down a hybrid car. Dry-chemical extinguishers are one-time-use only, regardless of how little was squirted out, while clean agents won't mess up the valve, leaving the unit useable. We'd get one of each, and then use the MaxOut if the HalGuard didn't do the trick. Regardless of type and manufacturer, make sure the extinguisher you buy is UL-approved and suitable for its intended purpose. Then mount the extinguisher(s) securely and within reach. You don't want a heavy steel container smacking you in the head during a rollover, and you most certainly would like to be able to grab it if upside down and on fire.