Antifreeze ruined aluminum tanker

[Jim_P]

The company I work for hauls antifreeze in bulk. We had been using aluminum tank trailers almost exclusively. The consensus was that the antifreeze is used in engines with aluminum components there should not be a problem.

In the past few months, several trailers had to be put out of service, due to pitting and general metal loss. There are published minimums for the thickness of the barrel.

After some investigation, we found the PH of some antifreeze is rather high. One 50/50 premix had a Ph of 11. Most online sources say anything over a Ph of 9 will damage aluminum.

So, how is it we can put the stuff in cooling systems with aluminum components and not damage them?

 

[ctechbob]

Complete, fully formulated mixes? Have to say, that's interesting. You wouldn't expect it to be all that different, even if the tankers are a different alloy.

 

[JimPghPA]

Along with worrying about the PH, if ANY copper is in any of the antifreeze ( which probably would come from older vehicles with copper radiators if your company was working with used antifreeze ) it would interact A LOT with aluminum. Aluminum and copper are at the opposite ends of the electro-negativity chart and throw in any fluid that can act like an electrolytic and it will make a great battery, but a lousy way to prevent corrosion.

Copper in the antifreeze in your aluminum tanks will cause major corrosion problems.

Also never use any copper or brass ( which has copper in it ) pipe or fittings with systems that have aluminum, if water or any other electrolytic is in the area.

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Another thing that destroys aluminum even much faster than copper is mercury. But it is not likely for that to be in the mix.

 

[Chris142]

I bet it is electrolosis of some sort

 

[JHZR2]

I thought aluminum corrodes above a pH of 9 or so. I was also under the impression it accelerates as pH changes, I guess the protective oxide cannot re-form. So I suspect it was just too high, past the “sweet spot” where when mixed with water pH of ~7, it can protect aluminum without issue.

 

[mfewtrail]

I thought aluminum corrodes above a pH of 9 or so. I was also under the impression it accelerates as pH changes, I guess the protective oxide cannot re-form. So I suspect it was just too high, past the “sweet spot” where when mixed with water pH of ~7, it can protect aluminum without issue.

pH is higher than 7 when mixed with water on some coolants. Last one I tested was supertech LL antifreeze mixed 50-50 w/ distilled water at a pH of 9 for example. The SDS for the pre-mixed version of this same coolant also listed 9 as the pH.

 

[Chris142]

Is this antifreeze ready to be sold and used?

 

[JHZR2]

Is this antifreeze ready to be sold and used?

Chock full of dissolved aluminum?!?

 

[Jim_P]

This was all new antifreeze.

 

[Chris142]

This was all new antifreeze.

Any idea on what brand it was or was going to be bottled by?

 

[CatCam2]

But Bar's Leak seal makes a copper infused......used it many times with no issues.???

 

[Kira]

Does "all new antifreeze" mean a completely formulated product ready for retail with corrosion inhibitors?

Are the effected tankers old or purchased used? I'm thinking there isn't any load that the tanker manufacturers can't coat against.

 

[Jim_P]

We have switched to hauling the antifreeze in stainless steel tankers. There is an investigation going on right now. Antifreeze is a hazardous material that requires a placard to transport. The shipper is not supposed to load into non compatible equipment. In theory, the high PH antifreeze could have caused a spill if the product ate through the aluminum.

 

[Chris142]

Chock full of dissolved aluminum?!?

Ya no kidding!