From: John De Armond Subject: Re: burning a tire Date: Sun, 03 Oct 1999 04:54:49 EDT Newsgroups: rec.outdoors.rv-travel "Light, Ed" wrote: > > Neon John <johngdNOSPAM@bellsouth.net> wrote > > > Been there, done that, have the pictures :-) Tossed a few tires on > > a bonfire. Neighbor called the cops. Cops threatened the death > > penalty unless I put it out. Couple of squirts with the garden and > > viola! A pile of smoking gooey carbon. Tires were easier to put > > out than the bonfire. BFD. > > Thanks for the info. I wonder why some tire fires are so impossible. Look at how many acres of them typically burn in a dump fire. When the fire is 10 or 20 layers down, it's kinda hard to get water on it. > Is it your impression that the tire has to be completely smothered by the > water? Maybe it's something a fire extinguisher can't do. A fire is extinguished one of 3 ways: 1. remove the fuel - not an option in this case. 2. cool the fuel 3. deprive it of oxygen. Any of the three will extinguish the fire. The other consideration is to cool the surroundings to the degree that rekindling is not possible. Water both cools and smothers the fire. The steam produced smothers fire not directly contacted by the water stream. Dry chem ONLY deprives the fire of oxygen by covering the fuel and by decomposing and liberating CO2. Ordinary dry chem is nothing more than baking soda. A more advanced extinguishing agent, Purple K, is potassium carbonate, first cousin to washing soda. it works better on materials that are pyrophoric (tending to spontaneously ignite in air) or reactive because it melts easier and flows over the fuel. This is just a plain old Class A fire. If you can get extinguishing agent on it, it will go out. QED. Getting the agent on it in the case of a small dry chem extinguisher might be a trick. If I ever thought I had any risk of a tire fire on my RV I'd arrange for a water hose off the system's water system. Water is probably the best agent for this type fire. Biggest problem is figuring out you have a tire fire. I once flagged down an 18 wheeler with a trailer tire fire. Driver didn't have a clue. Fortunately it was a flatbed or it would have burned down. From: John De Armond Subject: Re: burning a tire Date: Mon, 04 Oct 1999 04:01:03 EDT Newsgroups: rec.outdoors.rv-travel "Light, Ed" wrote: > > So, John, what do you think of putting out a tire fire by smothering it > with a blanket? Is that a myth or a good idea, if the fire extinguisher is > inadequate? Well if the tire was laying out flat on the ground and the blanket was one of those GI heavy wool ones and I had nothing else.... OTOH, one of these modern poly blend blankets - I suspect it would melt into a little ball of goo almost instantly. I'm sitting here trying to visualize cuddling up with a burning dually trying to tuck the blanket all around the tire so air can't get in. Hmmm... If you kinda toss it over the top, well, you've just added some fuel to the fire. One of the things they hammer into you in fire school is to think outside the box. If a blanket is all you have, you use a blanket. Might not work but OTOH, if you do nothing.... John From: John De Armond Subject: Fires and Re: burning a tire Date: Mon, 04 Oct 1999 18:08:02 EDT Newsgroups: rec.outdoors.rv-travel "Light, Ed" wrote: > > Neon John <johngd@bellsouth.net> wrote in message > news:37F85EEC.BD30B730@bellsouth.net... > > > > John, another question. > > Is there a fire extinuisher small enough to take along that's big enough to > douse a tire fire? Or is it a case of you'd never cover it well enough? I didn't mean to imply that the little extinguishers most of us carry in our vehicles would be too small. I don't know that. The problem would be since the small extinguishers lack a hose or a long nozzle, getting close enough to get the agent on the burning tire, particularly that part of the tire that is up under the cowling on an RV, might be impossible. The dry chem provides no cooling like a water spray would and it discharges so fast that it would be difficult to walk the stream into confined areas. Dry chem extinguishers will extinguish amazingly large fires for their size. If the powder adheres, it will probably put the fire out. Getting it on there will be a problem. I don't use dry chem in my restaurant. They make too big a mess and there is no hose or nozzle. I use 20 lb CO-2 extinguishers. These blow a cloud of atomized dry ice at the fire. It leaves no residue. These are probably too large for an RV. Too bad. They make really good beer coolers too! Just put the can in the horn pointed at the sky and squeeze. Instant cold :-) Speaking of fires, I saw a large class C burn down on I-75 today near here. Driver had enough warning that something was wrong - probably electrical - that he had time to pull into a rest area. Burnt to the frame. This brings up some more thoughts. We all have lots of money invested in our RVs. I wonder how many of us have systems installed to manage the stored energy sources in our vehicles. I'm speaking now of the battery system and the engine and fuel systems. Some items: * Central battery disconnect switches operable from outside the RV. This is standard hardware on a race car and the switches are fairly cheap (<$50). This switch can stop an electrical fire before it gets started good. I had the starter cable on my 68 Fury contact the exhaust manifold once and burn through. The large deep cycle battery that I use in that car almost immediately lit the 2 gauge wire red hot, exploding the insulation off of it. All the time it took me to get to the trunk, open the tool box and get a pair of wire cutters the wire was glowing red hot! That battery had a lot of Oomph! I was lucky the wire ran along the metal fender. Had a similar wire shorted under the dash, the car would have burned before I could have gotten the battery disconnected. That's the bad thing about an electrical fire in a vehicle. Until the battery is either disconnected or dead, or the wire burns in two, no matter how many times you put it out, it rekindles by itself. I'd used battery disconnects on my race cars for years but had never given it a thought on my street vehicle until then. Some may think it ugly but mine stick right through the side of the front fender for anyone to be able to operate. * Automatic fire suppression systems. These are standard equipment in race cars. Consists of a bottle of Halon (yes still available despite the EPA ban), some piping and nozzles and either a manual or automatic (or both) release. The nozzles are pointed at parts of the engine where a fire might start, at the fuel system and in the case of a race car, at the driver. A reasonable sized system can be bought for under $500. I have a system on order for my new used Class C. I think I'm going to install one in the generator compartment. Anyone who might think this is un-necessary might consider how often most people leave the RV with the generator running while they're doing something on a trip. All that's needed for a fire is a gas line to vibrate in two. * Heat/fire detectors interlocked with the RV's energy systems. Several years ago I wrote an article recommending that anyone with an indoors washer and dryer should install a rate-of-rise fire detector over the units and hook it up to dump power to the appliances when tripped and then described how to do it. The article had been on the streets for only a few weeks when I got what was probably the most gratifying letter I've ever received. A reader had followed my advice and less than a week after installing the detector, his dryer had a lint fire while he was at work. The fire tripped the rate-of-rise detector (which alarms when the temperature rises faster than 10 deg/minute) which shut off the dryer. His central alarm system alarmed and called the fire department who came to find an already out fire and a lot of smoke. Both he and the fire department gave credit to this detector for saving the guy's house. These detectors are fairly cheap ($50-100 ea) and generate a contact closure on rate of rise. And because they are rate of rise detectors, they don't trip when it simply gets hot. We used these detectors in the power house around turbines and large transformers where the temperature was ordinarily very hot. A simple relay feeds signals to the various energy sources - stops the generator, cuts off the LP, disconnects the batteries, etc. This is going to go on my new MH as soon as I get the time to finish the install. Kiddie makes the best detectors. * means of egress during a fire. Anyone ever think of how they'd get out of their RV if, say, the generator started a fire in the middle of the night? This is very close to home because I was trapped in my burning home (not MH) about 10 years ago and barely got out! If you rationalize that you can figure something out on the fly, you're fooling yourself! For all their high prices, our RVs are little more than mobile homes when it comes to fire. These things practically explode when the fire starts. Think about how you'd break out a window to escape if necessary, for example. Oh, BTW, I'm not a fireman. I'm aa retired nuclear engineer who volunteered for various fire brigades over the years. Legs were too bad to let me play fireman for real :-( John From: John De Armond Subject: Electrical fire Date: Wed, 13 Oct 1999 20:21:30 EDT Newsgroups: rec.outdoors.rv-travel This is in the general category of "teach me to run my mouth"... Last week I talked here about some precautions one can take to avoid an electrical fire in an RV. 2 days ago I got to experience the benefit of those precautions. I had an electrical fire in my 68 Plymouth Fury. Not a MH but the principle's the same. I was driving down the interstate when I smelled something odd. Not really a burning smell but more like overheated chlorinated solvent. A few minutes later the dashboard erupted in smoke. Tried to turn the ignition switch off but it was frozen. Locked 'er down, skidded off the side of the road and was out of the car and was hitting the battery disconnect switch before the car had quit rolling. After a few tense minutes with the fire extinguisher waiting to see if anything had caught fire, the smoke cleared and I could see what had happened. The less-than-one-year-old ignition switch had started overheating. It relaxed the tension of the spade lug connector bringing power from the battery. This let the lug overheat which melted the nylon connector. This was the solvent smell. The hot wire drooped down and laid across a ground wire. When the insulation melted, there was a direct short from the battery to ground. No fuse and on this old car, no fusible link. Had I not installed a battery disconnect switch, this wire would have burned until it melted. It would have surely have set the cellulose-based sound deadening materials under the dash on fire. The battery wire was smoked all the way back to the starter relay where it branched off from the battery lead. I got some alligator clip jumpers I carry in my toolbox for emergencies and jumpered power to the ignition, fuel pump and alternator and drove home without problems. A couple of hours spent rewiring the battery circuit and replacing the ignition switch with the old 30 year old one that was replaced because the key fit was loose and the car was back to normal. Lessons: Install that battery disconnect switch. If I was doing it over again, I'd install one of the switches with a remote actuation cable that could be operated nearer the cockpit. Every second matters. The battery wire had melted its insulation. It had started melting through nylon tiedown clips that fastened it to the body at various places. When those burned through, the red hot wire would have contacted flammable materials at several places. Have that fire extinguisher handy where you can reach it from the driver's seat. Mine sits on the floor between the seat and the door on the driver's side. Consider a race car-style fire suppression system. My old Fury probably isn't worth it but my MH surely is. Pay attention to odd odors. I normally would have stopped to figure out what the odor was but I'd just passed a bridge that was being stripped and painted and assumed that the odor was paint solvent. Bad move. Carry some electrical jumpers in your tool kit. Mine are 3 feet long and made from 14 ga wire and alligator clips. I keep a half dozen in the tool box. Figure out how to get your vehicle running again if you suffer a massive electrical failure. It might not be practical for a fuel injected engine but for a carburator engine, identify a place to feed power to the ignition module, the electric fuel pump if present, the alternator if it needs it, and to the starter. This can save a very expensive tow or roadside service bill. More importantly, it will allow you to drive the vehicle away from a dangerous area. I learned this lesson years ago when I was fooling with British cars where electrical failure is a daily fact of life. (Sir Lucas, Prince of Darkness!) This wasn't the first time that my little jumper kit has saved me a lot of hassles. John From: John De Armond Subject: Re: Electrical fire Date: Thu, 14 Oct 1999 04:07:06 EDT Newsgroups: rec.outdoors.rv-travel GBinNC wrote: > > On Wed, 13 Oct 1999 20:23:40 -0400, Neon John > <johngdNOSPAM@bellsouth.net> wrote: > > >Install that battery disconnect switch. If I was doing it over > >again, I'd install one of the switches with a remote actuation cable > >that could be operated nearer the cockpit. > > Sounds like an outstanding idea, John. Where would one purchase such a > device, or were you talking about fabricating it yourself? This is a standard race car and heavy equipment part. JEGS racing parts (http://www.jegs.com) has one listed for $19.95. They've gotten so whippy-kool with their java scripts and such that I can't extract a URL to take you directly to the picture. Click "products" to the left, then "ignition & Batteries" and "Jegster Master Disconnect Switch." You'll see a picture. A better switch can be seen at http://www.martelbros.com/flaming/switches3.htm. I've seen these on heavy equipment. This is another source for the same switch that JEGS has: http://calrewire.com/1998_Catalog/Switches/Switches/switches.html. One of my favorite companies for automotive wiring supplies is Waytek. 800 328-2724. They have a web page but it is still inviting you to ask for a free 1998 catalog! In the current catalog, they have 2 full pages of battery disconnect switches. The basic switch, #44030 lists for $18.16. This is the same switch as you see at the JEGS site. Switch #44031 includes an aux contact to isolate the alternator circuit at the same time and lists for $22.80. Recommended, as shorted diodes in the alternator can cause a fire. Cable-operated versions of this switch can be had from race car supply outfits (can't lay my hands on a catalog at the moment) but most guys just drill a hole in the switch handle and fit up a heater control handle and flex cable. Easy push-pull action. Wherever the handle is located, a sticker bearing the standard lightning bolt inside an upside-down triangle should be fitted. This is the standard marker in racing and (I think) aircraft and most emergency responders are trained to know what the symbol means. The switch should come with a decal. From: John De Armond Subject: Re: Electrical fire Date: Thu, 14 Oct 1999 17:35:13 EDT Newsgroups: rec.outdoors.rv-travel "Will R." wrote: > > > > SNIP > > When the insulation melted, there was > >a direct short from the battery to ground. No fuse and on this old > >car, no fusible link. Had I not installed a battery disconnect > >switch, this wire would have burned until it melted. > What happened to the orginal fuseable link? If memory serves me this > car had one. It probably melted or corroded and got replaced with > wire years ago. Well, you see, It's like this. When you use an antique car as a daily driver, you end up with a clip board with several sheets full of to-do items. Rewiring the engine compartment is on that list :-) The firewall terminal penetration had long ago started failing. the previous owner had put individual spade lugs on the circuits that had failed. I did that to the whole mess and sealed it in some fireproof mastic a few years ago. I imagine the fusible link was part of that block. Under the general theory of closing the gate after the horse's gone, I just ordered some stuff from Waytek including a breaker designed to replace the fusible link. fix that problem once and for all. What we do for the vehicles we love! John |
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