I have arrived at a totally non-destructive method to clean and rejuvenate a Clogged/Dead Coleman 400 Generator. It is not Heat & Quench! I need a badly clogged, non-functioning generator as a conclusive and unequivocal test platform. So far, testing on my end with 4 generators has proven extremely successful and encouraging, but I don't know just how bad my generators were to begin with. Generators will not be damaged in any way and there is a strong possibility participants will get back a functional generator in "Like New" condition. That's what this testing will determine. ONLY Generators from Coleman Stoves: 576, 400(400-499), 400A(400A701), 508 (not 508A/508B)! Please contact me at @Boron40 via this post if interested! Thank you! Ron
Am all ears on this one. Any chance of sharing this wondrous method with us mere mortals? I have a Coleman 533 and 442 both of which clog regularly, but I find heating them with blowlamps temporarily bring them back to life. No idea how or why.
Hi MFM ( @manfrommanchester ) I absolutely do intend to share it, but for the moment patience is appreciated. That is because I am on a quest to solve this "method" on my own and I have not proven its efficacy. I am enjoying this challenge and its resolution and all the bumps in-between. So until its ready it's not ready. The guys who report back that little flames and smoke come out the ends with the Heat and Quench made me call those carbon deposits "wet". I arrived at this after John @presscall included a few pics from a generator post mortem / autopsy that showed a whole dry carbon deposit. ------------------------------------- From John ---------------------------------- Alas, I can perform no miracles on Coleman generators of this size. Nearest I got to trying was in THIS post where I tried heat/quench/ultrasonic clean/compressed air. Finally, defeated, I sliced along the length of the generator to see where the internal crud preventing it from working properly was lodged and why the various ‘treatments’ hadn’t dislodged it. The hard carbon deposit was here … … and only the cutting disc of the Dremel dislodged it. I concluded that it was immovably bonded to the interior wall of the tube and only mechanical scraping or cutting (as with the abrasive cutting wheel) could shift it. It gave me even more cause, if needed, to avoid burning pump gasoline - with consequent deposition of additive residue - in my stoves. ------------------------------------- From John ---------------------------------- END------------------------------------------------- I wondered about what is actually doing the clogging inside the pipe. Plus the 400-499 stove is a smaller diameter generator tube with bends and a valve soldered on one side. So there are no user-removable items like in the bigger stoves. It has to be done in place... if it can be done at all. When I heard about Heat & Quench it I couldn't really see how that could ultimately work. It sounded like more burning on the generator via a torch (aka Blow-Torch and NOT a FLASH-LIGHT) (OMG!, speaking English to The English and Americans is a challenge) that initially got clogged from being burned by the flames of the stove itself didn't seem like a real solution. In fact, it reminded me in principle to an analogous solution I hear HERE in Florida when a huge hurricane is approaching. Someone will suggest we should just throw a nuclear bomb into the eye of the hurricane and that will fix the problem. In reality, none of the meteorologists and physicists thinks that is a good solution. Looking into the incineration thing further it is suggested that carbon deposits will start to burn away at 1022F or 650C. And since brass doesn't melt till 1750F or 950C it might just work. When someone with a torch (see above) that hot wants to experiment, I too, will be all ears. So I think there are wet carbon deposits and dry carbon deposits. The wet takes up more volume and gets reduced in size to dry carbon deposits. Eventually these dry deposits will build up and up with repeated Heat and Quench treatments. Eventually, comes the day to pay the piper. Would it be prohibitively expensive to ship it one way to Florida for me to try to clean????? I am assuming it will be less than $10 USD 1 way (7.50 GBP)
Oh, and I didn't say that I will ship it back when I am finished whether it is repaired or not. But it will be none the worse for waer from my treatment. Can't speak about the shipping!
My understanding of heat and quench is probably way to simple to a real scientist. But, I thought that the quench was an introduction of high temperature steam and pressure that REMOVED the deposits. They blew out the ends. My negative experience with heat and quench was the cracking of the brass tube from, I assumed, the pressure inside the tube. Old methods to clear generators was - Heat and Blow -. A pump simlar to a bicycle tire pump was used to blow air into a heated generator that was mounted onto a fixture on the end of the air tube (pump). I believe that they knew then the risks of heat and quench. There are photos here, somewhere, of such devices.
@snwcmpr Like you, I have assumptions about the Heat and Quench generator cleaning technique. I know metallurgy science deals in depth with the Heating and Quenching of metal to increases its strength and also brittleness. Its a whole big science that I know nothing about other than it exists and Quenching has a big role to play. I would be reluctant if not loathe to HEAT and QUENCH anything repeatedly because I do not know the exact ramifications of that technique. But I know it will do "something" to the metal, though no idea if I would be helping or hurting the generator. The generators I am focused on are the Coleman "400" et al. generators that have turns and angles built in and are a much smaller diameter than the standard Coleman generators making it more difficult to work on. I do not see any possibility for steam pressure to be created because #1 the tube is not a closed vessel to build pressure and more importantly #2 the volume of water overwhelmed the amount of heat stored in the metal never allowing any water to have its temperature raised to the point of creating steam in the micro-second of the QUENCH. Its quite the opposite that occurred. My #5 Running Assumptions: #1 - I believe multiple HEAT and QUENCH cycles would hurt/damage/compromise the generator in some way. #2 - I believe the cracking of the brass tube you experienced was a negative consequence of the QUENCH that caused brittleness. #3 - For generator cleaning I would think the HEAT does all the work and the QUENCH is relatively unimportant and merely allows the human to touch it safely. #4 - As for the HEAT, there are reports on flame and smoke coming coming out the end. I can't see that coming from burnt on dry carbon so I think there are wet gooey deposits of some sort that are greater in volume and clog the generator. When HEAT is executed the wet deposits are burnt down further to a dry carbon that is reduced in volume allowing for continued generator use for a limited time. #5 - I believe successive bouts of Heat and Quench puts successive layers of dry carbon deposits atop one another making for a more severely compromised generator by actually compounding the problem and making rectification all the more difficult if not completely impossible. If I am completely wrong I would welcome correction. I am fascinated but in the dark about this stuff. Other theories always welcome.
I think the idea with heat and quench is that the metal generator and whatever is clogging it will expand and contract (from heat and cold) at different rates, and the quick cycling of temperature may break the gunk free from the metal. The risk is that the quick expansion and contraction may cause the tube to rupture. ….Arch
Note: Partial quote only for brevity. I was only referring to closed/blocked cavities. My worst experience was an original Preston Loop that cracked and was later unusable.
I'm really pushing for dry ice blasting of generators. Liquid CO2 from a sodastream/paintball tank turns into high velocity, solid CO2 particles that impact against carbon deposits. At -110F/-80C it also functions as a "heat and quench" but in the opposite direction. A cool and contract, if you will. These low temperatures make things brittle and can aid in causing carbon to fracture off in chunks. The CO2 snow also vaporizes and expands in volume too. This has the effect of dislodging more carbon and forcing it out of the generator. If carbon is soluble in high pressure CO2 then it'll remove every last bit of it too, but that's not something that I've yet to confirm.
I know this is an old tread, but are you still looking for old stoves? Or did you perfect your method? I have a 400A with a clogged generator that I would love to get working.
Hi, They are listed here. FS: Reproduction 400/508/576/505 Generators, only $50! - The Coleman Collectors Forum
That's awesome, thanks, I'll consider it. However, I did get this stove for pretty cheap at secondhand store and was hoping to figure out a way to fix it myself, so if anyone has tips beyond heat/quench (which seemed to make it worse), I'd be interested. This is my first introduction into this world, but it seemed before the heat/quench, if I got the adjustment lever in just the right place, it would work a bit, so I'm guessing that may be where the source of my troubles lie?
My most successful method has been heat and air while the gas tip is remove. Remove the gas tip and carefully warm it up, making sure to not melt the braze. Blow through it with an air compressor to burn off the coke. Be careful with the fragile needle while the gas tip is not protecting it.
Hi @kosmicsea No I am no longer looking for Coleman "400" style stoves. But I have had some pretty encouraging success resurrecting old, clogged geneators. I seem to have had luck with this technique. You may not. I make no claims or guarantees as to its safery or efficacy. All generator blockages may be different. One may be impoosible to clean while another easy to clean. This is meant for the 400-499 Peak 1 Brown stove with metal F/A tube. It will, of course, apply to others in the "400" Stove "Family. My technique uses the following parts/processes: - 1 gallon can Berryman "CHEM-DIP CARBEURATOR PARTS CLEANER" w/ grate to submerge parts from Napa Auto Parts store. - 1 Ultra-sonic cleaner with small amount Purple Power detergent. (Use any cleaner you want or none. Who kows?) - Compressed Air (a compressor w/ A Blow Gun Chuck) - A fully perfectly functioning 400 stove as a "Test-Bed" or more accurately a working "High Heat and Flame and Pressure Bed" to work out the kinks. My technique follows below: - Remove the jet tip from 1 or more "400" style generators and submerge into the CHEM-DIP. - Let it sit submerged for 1 - 3 weeks depending on clog severity. Remove. - Blow inside of tube with compressed air to flush the CHEM-DIP. - Place in ultrasonic tank for 1-5 1-hour cycles. I've never used more than 2 cycles. My model has heat which I turn all the way up to 50 C. Remove. - Blow inside of tube with compressed air to flush water. You can't do this enough!!! - Run a wire carefully through the jet tip orifice to clean it out. Use a bright light and magnifying lens if need be. I use an internal wire from a previous old, dead generator. - Re-Install jet tip. - Re-Install Generator onto fully functioning 400- style stove specific to your specific generator. - Follow normal Lighting Instructions. - It is expected you are a knowledgeable 400 stove user and can light one easily under normal circumstances. - It is expected you know how to turn off the Red Fuel Valve and know when and how to do so immediately to prevent fuel escaping and fires. - It will fail to light. It will continue to fail to light. Keep trying. - Once you get any sort of flame out of it DO NOT RUSH IT. - Why are you running into these ridiculous problems??? - Because the generator and Black Valve are full of water!!!!!!!!!!!!!!!!!!!!! - There are three ways to overcome that. The first is the BRUTE FORCE method above. - Sometimes it works very quickly with just a few minutes of sputtering. - Else pump it up, open the valve to bleed the water and replace with fuel. NO MATCHES OR FIRE AROUND. DO NOT light it. - Else, with NO FUEL IN THE GENERATOR and the Red Fuel Valve closed heat the generator with a propane torch. Not too much, too little or too long. - Remember you are trying to evaporate water not silver braze. - Start again: Follow normal Lighting Instructions. - You should be getting a flame and it may be very good. Or it may be sputtering for the next hour but getting better minute by minute. - Lets assume you got your stove running and burning normally and lets assume that is now. - You may discover an ultra-fine soot like "Lamp-Black" depositing on the inside of the burner bowl right where the flame tips come out. - CONGRATULATIONS! Your internal clog has been broken down by the chemical. It continues to be broken down and ejected by the heat and pressure of stove operation! - This can go on for up to 5 tank-fulls or 6.5 hours of operation. It is very messy but super easy to clean with paper towels and any solvent. I hope this may be useful to somebody. All The Best! Ron
