Don't try this at home or adult supervision required, sound familiar? At the risk of more embarrassment and a few of the self righteous people on the forum calling me an idiot( may be some truth to that) I thought I should share this experience so that someone else doesn't have to repeat it. About three weeks ago I bought a plastic stock tank at the local farm and ranch store and borrowed Stan's 36 volt battery charger. I have some House wire wheels I thought I would clean up using electrolysis to remove 4 layers of paint and a little rust. I had some rebar, bought some Arm and Hammer washing soda and away I went. The first 5 wheels I did it went fairly well, although it took longer than I figured it would. Yesterday I decided to do two more, so I drained the tank, scrapped all of the junk out of the bottom, added water, two cups of washing soda and hooked up a set of jumper cables to the wheels and the negative cable on the battery charger. The positive cable was attached to the rebar and I had some 6 gauge wire run from one group of rebar over to the other rebar. I noticed it was pulling 35-40 amps on the meter which was about 10 more than what it had been doing. I assumed better contact with the wheels, cleaning up the rebar, fresh water and baking soda made the difference. I had previously let the tank run all night and although the water and wire was warm, it was not hot. The phone rang about 12:30 and my son said the police just called him and the garage was on fire. Half a sleep I stumble downstairs and go out the back door. I have 4 fire trucks, a rescue vehicle, and squad car sitting there. The fire was put out by the a local police officer with his fire extinguisher. I unlocked the garage and went over to the charger which was still running and shut it off, didn't notice what the amp gauge was reading. All I can assume is that the jumper cables got hot enough to ignite the plastic stock tank which burned down to the water level. Luckily the damage was limited. The tank was outside, partially covered to keep the dogs and kids out, but had plenty of ventilation. I believe the charger still works, it was on a 20 amp circuit breaker which did not kick, I don't think the circuit shorted out, but that I was drawing to many amps for the wire. It may remain a mystery. I forgot to go out at before I went to bed and check on it. I got lucky on this one, the downside is I now have to clean the outside of the garage as well as the inside.
John, glad this didn't turn into a real tragedy.
If I understand this correctly, it is essentially Stan's fault?
Glad to here that all worked out that well. YA
I think you can blame Stan, he's has strong sholders,but just don't ask him for help again GRIN. Did the wheel get clean?
PS Haven't been there or done that but I could have. Thanks for the heads up.
how could this have been avoided though? Sounds like you didnt do anything dangerous. How were you supposed to know the wire couldnt handle it. I guess the moral of the story is put it on a larger circut? Im glad it turned out okay in the end.
Wait until you get bills from fire and police. You'll need the ambulance...
Glad no one was hurt. Now I'm also glad I don't have to hear Stan's response... On a positive side you just may become another of Stan's many stories.
Rob--now that's starting to sound like a lawyer!!! LOL
I'm glad you are ok. All the rest can be repaired, repainted, etc.
Thank you for sharing -- and hopefully someone will be able to tell us why the extra current draw etc. I.e. it worked fine the first couple of times but at a lower current/Amp draw.
Hap l9l5 cut off
Rob, I think your right, essentially it's Stan fault.
Did they bother to ask you what you were doing with that contraption?
That thing looks home built reactor!
I am glad I live far enough away that I can't here Stan. I hope the charger still works. LOL
"Shouldn't play with matches !!"
I could not tell for sure, but it sounds like you changed the set-up for the second batch of wheels. I believe the current draw would increase if you increase the surface area of electrodes (number of wheels or number of rebar rods). More attention to the set-up with some limit to the current(amps) to prevent over-load of the power source and cables should prevent the problem. Just checking the temperature of the conductors as well as the amp meter should tell you whether to decrease the electrode size/number to prevent over-heating cables.
I could not tell for sure, but it sounds like you changed the set-up for the second batch of wheels. I believe the current draw would increase if you increase the surface area of electrodes (number of wheels or number of re-bar rods). More attention to the set-up with some limit to the current(amps) to prevent over-load of the power source and cables should prevent the problem. Just checking the temperature of the conductors as well as the amp meter should tell you whether to decrease the electrode size/number to prevent over-heating cables.
Higher amounts of dissolved solids in the water will increase the electrical resistance. I have built load banks to test the output of gasoline powered generators using a 30 gallon plastic barrel filled with water and some table salt added. The generator leads are connected to rods placed in the barrel opposite each other. The generator is run and salt is slowly added to the water. The generator will work harder and harder until it gets to the point where I can kill a 20 hp gasoline engine with a shot glass full of salt.
Rather be lucky than good any day! Lucky you John!!!!
John, glad luck was with you. You might consider buying a lottery ticket.
William, the set up was the same as I had used before, same electrodes, two wheels, same cables, maybe slightly more A&H washing soda(2 cups), but not much. Lesson learned, when doing things like this you may not need to stand and watch, but you better be able to monitor it every once in a while. The barrel sitting by the garage is for my new hot tank. Now I'm not so sure. Randy I used to subscribe to the theory if a little is good then a lot must be great, but I got over that one a long time ago. Your research is interesting, amazing how things work. AND Lucky is probably an understatement. No T's in that garage.
Proves that there is something to be said for cement block garages and steel doors on garages.
First I've heard about this. Would have been cheaper to take the wheels down and get them sandblasted, eh?
I think Randy D has it backwards? I believe that the more dissolved soda (or salt) results in a lower electrical resistance and therefore a higher amount of electricity flowing. Adding some soda could have tipped you over the thermal/resistance cliff. More surface area, differences in the rust surface area or thickness of rust has a similar effect, however is less predictable.
I use a battery charger with an ammeter in it to keep an eye on the current draw. I also routinely put my hands on the cables, clips, and connections to make sure they are not getting warm.
I have run several items overnight, but usually, check it often.
Anyway. Thank heavens it wasn't much worse.
Drive carefully, and enjoy, W2
Wayne, No I do not have it backwards. Do you think I made up the story of how to make a load bank?
I do not mean to offend you. But adding salt to the water increases the capacity for the water to carry electricity (reduces the resistance), therefore adding (current) load onto the generator. Pure water will carry almost no electricity whatsoever (high resistance). It is the minerals in the water that carry the current.
I do not consider myself a "true" expert on electricity (I just know more than 95% of the population). My dad was a true expert. And I have worked in the field most of my life. There are a couple people on this forum that I highly respect, admire, and look forward to their explanations because I am still learning from them.
I don't doubt your tale about loading generators to test them. I can see how it could work. My experience simply says you stated "increase" or decrease the resistance by higher or lower amounts of solids dissolved in reverse.
No offense intended.
Drive carefully, and enjoy, W2
Sometimes if helps to go back to the source.
Ohms Law, V = I R (or I = V / R)
Voltage = Current times Resistance
If you hold the voltage the same and decrease the resistance then current goes up, and vice versa.
You are right, I did have it backwards.
No problem. I was just trying to keep things straight.
Thank you for your participation. Without such participation, this forum would dry up and look like a few others.
Drive carefully, and enjoy, W2
If the charger is putting out 36 volts and you had 40 amps of current flowing then you had 1440 watts of power going somewhere and if that power was converted to heat - well....
I always think it a good idea to limit and thus control the amount of current. Just monitoring it with a meter is not controlling it since what happens if the current increases and you are not there to see it and reduce it somehow? It is easy to play Monday morning quarterback here and state what should have been done but I don't have a good track record myself with my previous near disaster with linseed oil and my shop garbage can fire. I do think that home made shop apparatus ought perhaps to only be used when you are present and can be made then aware that something is awry. I am just glad the whole situation wasn't worse and that you too like me escaped tragedy by an eyelash. I very much appreciate your sharing your story here so that we all can learn.
I too wish to thank John S for sharing this with all of us so that maybe someone can avoid a similar or worse situation. As I recall, I thanked you for sharing your tale at that time. I also thank you for explaining what I thought I knew about the cause but I did not know well enough to explain. You are one that I do very much look forward to postings explaining the how and/or why of things electrical.
As for your past incident; My dad used to say that we are all dumb. Just about different things.
Thank you to all.
Drive carefully, and enjoy, W2
John R. The charger has no way to control output. Would using less rebar or sodium bicarbonate reduce the draw, thus less heat. I know we can probably only speculate on the cause, but people have doing this for years and so far I'm the only one I know who has tried to burn down a garage.
Yes reducing the surface area of the anode (rebar) and/or reducing the concentration of the sodium bicarbonate will reduce the current draw. There may be a problem with not enough surface area of the anode because the process works pretty much in line of sight. If there is not a direct path from the part to the rebar it will not work.
I often use a DC welder and a steel or stainless steel tank for rust and paint removal. The whole tank served as the anode. I only use about 1/4 cup of washing soda in about 10 gallons of water. It does work pretty fast and the water does get hot. I don't leave it unattended very long.
Stainless steel used for an anode releases poisonous chlorine gas.