Antifreeze Experiment & Testing
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)
Attached a copper lead wire to each
and for the electric current. 800mA 12v DC transformer
although it said 12v its really 16.4v but it will still work. your cars electrical system is around 14-15 volts when the alternator is running anyways so this is pretty close.
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.
theres about 15.5 volts sustained across all 6 cups.
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.
@2hours
@24 hours
#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
@24 hours
#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
@24 hours
#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
@24 hours
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 crap 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.
after some cleaning, notice the pitting
50/50 G12 and Peak. notice the localized green stuff and the formation of a pink film like substance and very little pitting.
cleaned up
liquid turned pretty milky, but not nearly as much solids as the 100% peak.
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Originally Posted by JaVa
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