SORRY about all the newbie questions but what exactly is HF acid, and also to clear things up I was not going to mix the soap and the acid in a bucket, I was going to T-off my injector line and pull from my acid and my soap buckets (I guess still a was of time????). I have 1 more ? will the citric acid hurt the windows real bad, Just wondering I am going to try two-stepping today, wasn't sure if i should put acid on the whole truck or try to stay away from the windows. Thanks Philip