OCBen

Well, we were discussing how to neutralize and stop the etching action of the acidic bird bomb. I see you understand that the only way to stop the corrosive action of an acid is to immediately use a base. That’s what is done in the industrial processes of photo etching, chemical milling, metal acid etching, etc. where the material removal process of the acid is halted by an immediate quench in a base solution. Bird droppings are very acidic, typical pH values are from 3.5 to 4.5 (don’t ask, okay, I got it from autopia.org). And to immediately stop the etching action of a fresh one you need to neutralize it by bringing the pH up to around 7 with a base solution of, say, sodium bicarbonate.

Now, it seems that you are addressing the issue of breaking up and dissolving a hardened clump of bird crap, which if it’s already hardened it can be assumed that the acid was fully spent in doing the maximum amount of damage. In which case it’s too late and all you need to do is remove it, which I would do with a simple hosing down with water until it was soft enough to rinse away. I would never use vinegar (an acid) on my car’s painted surfaces no matter who says it’s okay. I don’t blindly follow someone’s recommendation if it doesn’t make sense to me.