How to fix corrosion from leaking battery cap?

Rod in Forfar · Apr 19, 2015

When I bought my low-hours 2005 Kubota B7510 two years ago it had a piece of tape over one hole in the battery. Eventually I replaced the cap, but in the interim the fan drew a bit of acid as far as the screen. Of course the HST cooling tubes lie between the battery and the mesh. Now they're a bright orange and there's a white precipitate sitting on the ledge below them.

What do I do?

Thanks,

Rod

Sysop · Apr 19, 2015

Take a can of Coke and pour on everything to saturate it really well. (being in the mesh part you may even want to use some sort of brush and brush it in really good). This will stop the reaction of the battery acids. Clean the Coke off really well and spray everything with something to protect it.

peterc38 · Apr 19, 2015

Sysop said:
Take a can of Coke and pour on everything to saturate it really well. (being in the mesh part you may even want to use some sort of brush and brush it in really good). This will stop the reaction of the battery acids. Clean the Coke off really well and spray everything with something to protect it.

I'm curious about this as Coke has phosphoric acid in it and is a pH of 2.8. So how does it stop the reaction of the battery acid?

Sysop · Apr 19, 2015

Never really made sense in my mind either; but I'm not a chemist so I can't explain it, I just know it works. It's been something folk have done for decades to dissolve the corrosion and stop the reactions on battery terminals and other components that've been leaked on for longer than I've been alive... Pour some on a corroded battery post and watch it all go away. Clean it up, coat it with some good stuff to prevent it from happening again. Fixed.

Quick search on the net said: Coke and many other soft drinks contain high levels of carbonic acid, which dissolves many substances easily, while still being weak enough to leave others unharmed. The carbonic acid eats away the corrosions, while not dissolving pure metals as quickly.

I would guess the main benefit is it removes the existing corrosions while rinsing away the more harmful acids, then getting it cleaned up and treated to prevent future occurrences is the actual fix.

boomer1025 · Apr 19, 2015

I always use baking soda mixed with water for cleaning battery terminals or anything else that got battery acid on it.

peterc38 · Apr 19, 2015

boomer1025 said:
I always use baking soda mixed with water for cleaning battery terminals or anything else that got battery acid on it.

Right me too. Baking soda is a base (pH above 7).

peterc38 · Apr 19, 2015

Sysop said:
I would guess the main benefit is it removes the existing corrosions while rinsing away the more harmful acids, then getting it cleaned up and treated to prevent future occurrences is the actual fix.

It makes sense on some level I guess. The main ingredient in naval jelly which is used to remove rust is also phosphoric acid. It would still make sense to neutralize with a base afterwards to me. I know coke works great on frozen lug nuts

Gator6x4 · Apr 19, 2015

I am like Sysop and use Coke. I pour one of the 2 liter bottles in a hand sprayer, pump it up and really wet the area down. Let it set, wash the coke of, clean the area real good and then apply, a rust arrestor and inhibitor , primer and then paint or something like Eastwood Internal Frame coating, Amazon.com: Eastwood Internal Frame Coating Rust Prevention w/Spray Nozzle: Automotive, WD 40 also has a product for rust inhibiting. Be careful with the WD 40 products as they contain a lot of silicone. Trying to spray paint something that has been exposed to silicone will test your nerves.

s219 · Apr 19, 2015

I believe in this case Coke is just acting as a mildly acidic cleaner which will get rid of the existing corrosion deposits (which themselves are basic; i.e. , opposite of acidic). While the cause of the original corrosion is acidic, the crust that's left over is a basic. I'm not a chemist and was a mediocre chemistry student, but I have seen mild acids used to clean the white oxidation off corroded aluminum and that's how it was explained to me.