hey Old!

[glennster]

rich when you do a vinegar flush on a rusty cooling system, how long are you leaving the vinegar in? i have a pretty dirty one to do, was planning on overnight.

 

[old]

I fill the cooling system with vinegar and then run it till it gets good and warm or close to over heating if that bad. Then I let it sit and cool and then drain and back flush. If once isn't enough I do it 2 or 3 more times and back flush each time b way of the block drain

 

[glennster]

this tractor has a 40 quart cooling system. guess i will head to costco and buy a pallet of vinegar!

 

[old]

You can filter the vinegar after you have drained it so you can use it 2 or 3 times

 

[showcrop]

The vinegar breaks the rust down by oxidation, which is of course a chemical reaction. Almost all chemical reactions are enhanced by adding heat so as old posted the process is enhanced by running it up to operating temperature. However, the process of oxidation consumes the free acid ions in the vinegar so even though filtering the loosened solids may clear the solution up somewhat, reusing it won't do much for you.

 

[Matt in Oz]

Hey Showcrop

Done a bit of chemistry, how does an acid oxidise something? The acid provides hydrogen ions which in reality form H3O, water is H2O. So not sure how that works cause it is the hydrogen ions from the acid that do the work. Rust is an oxide. Vinegar is a weak acid which means not all the
ethanoic (acetic) acid forms ions so you may be able to reuse it. To confirm, all you would have to do is measure the pH. This could be done using a swimming pool or soil test pH kit (universal indicator). Measure the store bought vinegar pH then the recycled stuff to see if it has enough umph to
do the job again.

Respectfully Matt

 

[showcrop]

(quoted from post at 04:24:11 09/09/22) Hey Showcrop

Done a bit of chemistry, how does an acid oxidise something? The acid provides hydrogen ions which in reality form H3O, water is H2O. So not sure how that works cause it is the hydrogen ions from the acid that do the work. Rust is an oxide. Vinegar is a weak acid which means not all the
ethanoic (acetic) acid forms ions so you may be able to reuse it. To confirm, all you would have to do is measure the pH. This could be done using a swimming pool or soil test pH kit (universal indicator). Measure the store bought vinegar pH then the recycled stuff to see if it has enough umph to
do the job again.


Respectfully Matt

My objective was to not delve into the actual chemistry which no one would care about, but the desirability of adding heat, and the depletion of the effectiveness of the acid through the process.

 

[Geo-TH,In]

Rust is oxidized iron and vinegar is a mild acid.

 

[4520BW]

mild phosphoric works great to

 

[rustred]

no one has mentioned that there is different strengths of vinegar. from 5 percent to 10 percent. that is a biggy . basically a boil out in caustic is the way to go.

 

[OregonAaron]

I have used vinegar with good results as well. I have also ran a solution of CLR in a cooling system and it did quite well too.

 

[Turkeyfoot]

Normally acids will react with reduced metals (metals in their neutral, unoxidized state), not oxidized metals such as rust. In the case of vinegar, it dissolves the rust and ideally there won't be any reduction/oxidation reactions occurring. In fact if they did the hydrogen cation would be the oxidizing agent which means it would be reduced and turned into hydrogen gas. So unless your mixture is bubbling, then you are not doing a redox reaction with the vinegar. Instead, the acetic acid solution is dissolving the rust.

If you take a reduced metal like iron or aluminum and put it in a strong acid you will produce a lot of hydrogen gas, rapidly.