Steps used for a concrete acid wash must be strictly adhered to. If this process is not followed to the letter, you may find that the entire process has failed and you will need to start over at the beginning. You will find information below that will help you avoid these mistakes.
Avoid Working Large Areas
Do not work in areas that are so big that etched residue on the working surface will dry before it is flushed off. Areas that are allowed to dry can leave white stain or residue that you'll find hard to remove.
When applying the acid solution, pour it from a 5-gallon plastic pail. Do not splash the solution onto adjoining concrete surfaces that are not to be acid washed or stained.
Proceeding with neutralizing before you have checked the etched surface can result in failure of the entire process. The etched concrete surface should have the same feeling as 80 to 100 grit sandpaper in order for you to proceed to the etching step.
Neutralizing the Acid
Failure to properly neutralize the acid may necessitate your having to re-apply the acid. Uneven dispersing of the neutralizer will cause the same failure. Be sure to scrub aggressively and sure not to leave any area from being neutralized.