Antifreeze + electricity, what can we learn?

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http://www.audizine.com/forum/showthread.php/263790-Antifreeze-Experiment-amp-Testing Anyone feel like digesting and interpreting? I'm kinda busy... Every week someone posts about mixing antifreeze, whats ok to run? can you mix G12 with Peak? with Dexcool? well i set up a little experiment to see what exactly happens when you do. http://www.peakantifreeze.com/ It says right on the front page "Mix with any color antifreeze". we shall see.... http://www.getahelmet.com/jeeps/maint/dexcool/ some dexcool info. there also happens to be a class action lawsuit against the makers. more about that here. http://www.dexcoolsettlement.com/ Heres how its going down. i set up two different experiments to deal with two major problems associated with coolants- the "gel" supposedly formed when mixing G12 and anything else, and the galvanic corrosion that takes place over when you put regular old Peak antifreeze in an Audi engine that has many dissimilar metals. Experiment 1: mixing of coolants. undecided as how to accurately test this, as gelling occurs over time in the engine when you mix coolants. it has to do with contaminant build up in the cooling system getting trapped in the mixture, and also the heating/cooling cycle and getting pumped thru the radiator and water pump over and over. unfortunately i sold my little 12v D5 pump a few months ago, which would be perfect to circulate the experimental fluid. i may update this experiment in the future, but right now i have 4 cups- 1- control- 100% G12 2- 50% G12 + 50% Peak 3- 50% G12 + 50% Dexcool 4- 50% Peak + 50% Dexcool in each of those, i added 50% by volume of distilled water (1 part antifreeze mix to 1 part water) no real changes have been observed in regards to gelling or changing consistency. when i think of a good way to test viscosity il update this section later. (its the back row of 4 cups in this picture) Experiment 2: Galvanic corrosion Ok so this is a tough one to do on a timely basis. Galvanic corrosion occurs with two dissimilar metals, an electrolytic liquid, and an electric current. Over time coolant breaks down in an engine and forms substances that act as electrolytes. Couple that with the many different metals our engines are made out of (aluminum head, iron block, various other metals and alloys in sensors and other parts) along with fact that the entire chassis is one big negative electrode (12v ground) and you can see where galvanic corrosion comes into play. In this test, we are looking to see the rates metals corrode in different soloutions of antifreeze. There are 6 test subjects. (all mixtures are- half 50/50 mix antifreeze + half distilled water.) 1- Control - Distilled water. 2- G12+Distilled water - 50:50 3- Peak (green stuff) + Distilled water - 50:50 4- Decool + Distilled water 50:50 5- G12 + Peak 50:50 6- G12 + Dexcool 50:50 (bottom 6 cups in the above picture, left to right) To test this in a timely fashion, we need a stronger electric current to speed up any reaction we may see. I dont have 6 months to let the mixtures mix around in my engine. With this setup i got results almost instantly. I used pieces of aluminum about 1.5" and pieces of mild steel (couldnt find anything around the house that was pure iron, so this will do) I wired them all in parallel for two reasons- because i dont have 6 identicle power supplies to put on each of them, and by doing it this way, the current will take the path of least resistance and we will get a bigger reaction from the antifreeze with the most electrolytic capabilities. The mild steel pieces are wired on the negative side of the transformer, the aluminum is the positive. Results!: Ok, well almost immediately there was a reaction in a few of them. here are my notes, i observed the action at 10 minuits, 1 hour, 2 hours, and il leave it going over night and do a final look in the morning. #1- 100% water- 10 minuets - just about zero action, nothings happening 1 hour - no change 2 hours - few bubbles, not really anything still 24 hrs - still next to zero change, 100% pure water isnt a great conductor/electrolyte @2hours #2- 100% G12- 10min -some bubbles on negative side. 1 hour -no change 2 hours -no change 24hrs - very little change, although there is a small amount of green buildup, probably oxidization of the copper, though its only on the part where the copper touched both the liquid and air. possibly getting oxygen from the air to oxidize the wire, not from within the liquid. note- slightly less green buildup then dexcool. #3- 100% peak- 10 min -rapid bubbling on steel, green buildup on aluminum 1 hour -negative side still bubbling, heavy buildup, steel has darkened 2 hours -still progressing same as before, tons of green buildup on aluminum 24 hours - massive amount of pitting in the aluminum. tons of solid buildup in the antifreeze. copper wire was disolved completely. small discoloration in the negative side. test stopped. @2hours #4- 100% Dexcool- 10 min -some bubbles on steel, strange milky gel forming around both electrodes 1 hour -same, some green solid forming on the positive side wire 2 hours -same as before but slightly more progression 24 hours - almost the same as the 100% G12 although slightly more green buildup on the copper wire, except below the liquid line not on the surface. il let this go another few days. @2hours #5- 50/50 G12+Dexcool- 10 min -some bubbling on steel 1 hour -same, not much change 2 hours -sort of milky around the negative electrode, bubbling 24 hours - roughly no change, im going to let this go another few days and see how it stacks up with the strait G12 and strait dexcool. @2hours #6- 50/50 G12+Peak- 10 min -rapid bubbling at the negative side, milky haze around the steel. very heavy green buildup on positive side 1 hour -even more green deposit on the aluminum. lots of action. 2 hours -same as before plus the whole cup turned an opaque milky color. lots of green deposits on aluminum 24 hours - obviously lots of buildup although different from the 100% peak sample. the G12 definately limited the amount of solid buildup more then 50% (concentration of G12:Peak) and the way it built up was much different as you can see in the pics. the corrosion is limited to a small area, as opposed to the 100% Peak where the corrosion/solid formation just spread across the whole dish. slight discoloration (darker) on the negative side, some pitting. test stopped. @2hours right now it looks like G12 and Dexcool are very similar in regards to protecion from galvanic corrosion. Peak is garbage as you can see. it just about instantly started corroding. we will see what the electrodes and fluids look like after 24 or possibly 48 hours. UPDATE DAY 2 Well its confirmed. Peak antifreeze is total [censored] and has no place in our engines. Although- there was a twist on the results i expected. when comparing the 100% peak to the 50/50 peak and G12, the sample with the G12 in it did a great job at stopping more then 50% of the corrosion that occured in the 100% peak dish. the corrosion was limited to the point of origin and did not spread thru out the disk as happened in the 100% peak sample. also there was very little pitting on the aluminum in the 50/50 sample, but there was a pink solid layer that formed. i think that the G12 solidified on the metal to stop the reaction of the Peak. Below are some pics comparing those two samples. il let the other 3+control samples run a few more days to try and get a more pronounced reaction (the two samples with Peak in them corroded so much that it short circuted the whole line to the point that it was only reading ~8v. i cut the wires on those two samples and the voltage returned to ~16v) 100% peak @ 24 hours Frothy solid formed across the whole dish. Re: antifreeze experiment notes- i agree the copper could be taken out of the liquid for a more controlled test, but its important to note that it didnt corrode in all the samples. it had no reaction in the 100% water, and very little in the 100% G12/ 100% dexcool. also there is copper used in our engines, some gaskets and seals. i believe the test is still valid. and i agree that heating them up to ~185*F would be a bit more accurate, so would experimenting with used fluids with contaminants in them, but there isnt any practical way for me to do either of those. il update in a few days after i let the 100% G12, 100% dexcool, and G12/Dexcool mix and control dish run longer to try and get a clearer difference between them. UPDATE: its been a week since the test started, not a huge difference between dexcool and the G12, however theres something to note. compare these two pics, first is 100% G12 and the second is 100% dexcool theres a slight green buildup on the copper in the G12 sample where the copper met the air and liquid. however on the dexcool side, you can see there is some significant buildup on the whole wire all the way around, definately more then the G12. the 50/50 dexcool and G12, was similar to 100% G12. i figure thats a pretty solid result. now before i declare G12 the champion, i decided to reverse the electrical current, making the mild steel the sacrificial annode (positive side). i figured what the [censored], i could either throw everything out at this point or see what happens. il update in a few days with changes. there hasnt really been any change in the piece of steel through out the whole experiment, with the exception of it turning a little dark in a few samples. lets see if it will do something with some positive current thru it. its also important to note the control- 100% distilled water. its got some white deposits around the steel after 7 days. FINAL EDIT Ok folks, there has been some pretty good results with the reversed electrical current. At the end of the test i also measured the Ohms across the dish to determine how easily electricity was allowed to flow. First off, here is the control dish of distilled water... lots of rusting on the steel.
 
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This looks like a cool science fair project. This reminds me a grease mixing study I once did. The only thing I would do differently would be no electricity for galvanic corrosion, just copper and aluminium submerged and connected.
 
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Wow! I would never have thought that there'd be that much difference. Thanks!
 
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Thanks for sharing. I wonder how other "green" coolants, or even Prestone, would perform in this situation.
Originally Posted By: friendly_jacek
The only thing I would do differently would be no electricity for galvanic corrosion, just copper and aluminium submerged and connected.
It would be interesting to do a longer term study like that to compare. Maybe it's unnecessary though. I don't know anything about the effect of an external voltage source in galvanic corrosion.
 
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Its too bad that there was no HOAT coolant in this experiment. I know many including myself use G-05. -Rouphis
 
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Well, I certainly don't know what to make of all this but, Thank You Audi Junkie for taking the time and money to do all of this with pictures. This is a great starting place for others to take to the next level. As I have stated in the past. I have used so many different brand coolants in the same cooling system without knowing what the coolants really were. My main concern is proper engine cooling, heater core life and that I have good heat in the winter time. Radiators have rotted out due to road salt over time and I have replaced water pumps due to age/mileage(over 100K) but, I have never had to replace a heater core in any of my own vehicles and I have kept many vehicles in the area of 16-18 years. The only engines that I had to replace head gaskets or intake manifold gaskets on were engines that were know for these issues.
 
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I realize that others say...Don't use anything other that the proper coolant in your system(Honda Genuine, Toyota LLC/Red, FL-22, GO-5, G-12 etc.)I have used more brands...Maybe they were all the same type! IDK! I have flushed and probably used the wrong type, without issues! I have mixed without issues, meaning just doing a drain/refill. I don't think that what I had been doing was optimum but, I can't say that what I was doing was killing anything as I ended up junking many vehicles due to other reasons such as age/mileage/rot. I'm not encouraging others to do what I did as I am now trying to stray away from bad practices.
 
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