What ever you do,do not use HF acid on polished unless you have total control as in getting it on and off as in flashing,its not wise to NOT even get HF acid close to polished.
The film can be brushed off with a weak soap mix,the film does not usually show up until after it dries,right.I do not know what causes it to film at times and not at times........looks bright and shiney while wet but dries with a sorta white dirty film,only way I know of getting it off is to brush it or flash with HF acid which is a NO NO.
IT will help if you'll apply your acid first then your soap,whats how acid works best and the way it is meant to be used.Rinse the dirt off if every dirty if just light dirty apply your acid,apply your soap and rinse off......then if it looks like its going to dry with the dirty film sometimes you can re'apply your acid and rinse off,its has a 50/50 chance getting it off.IF it films every time you wash it which some do some don't,it'll be cheaper and faster to just brush it to start with,these type I give to my competitor,no kidding I do not like brushing,I've have nothing againest brushing tho,I'm lazy what can I say.
First off I'd warn him if he doesn't keep the polished cleaned nomore then once a month,it will be a bitch to you to try to keep it looking like polished especi'lly end dump.If he is asking you to spend alittle more time to make it shinning good again I would have told him to help me keep it that way by aleast getting it washed every two weeks or it will always need a little extra time but it will never look shinny new again unless he wants to polish it back out which will cost him a arm and a leg atleast a half leg,which why he needs to wash it atleast every two weeks if not more ifen running in bad weather.When the polished gets bad enough to not clean up most end dumps usually go to the HF acid wash which will cut the polish off leaving a bright shinny alum end dump,which is alot easier to wash,ha..always apply your acid first.
