This topic has been brought up quite a few times,But!!!!!,I have stripped manny a/c in my life and still do, from window units to 350 ton chiller units I have sold them clean and dirty depending on the condition of the coil,located in fort lauderdale the sea air and salt rots away the aluminum fins and some times cleaning them would be a negitive for me.Have any members or guests for that matter ever weighed a clean coil before removeing the copper out of the fins and then figured out what they have lost or gained?I dont want to hear your opinion of what you think it was, we need some real weights,I feel you are costing your self,after your labor,blades, and the time need to do this,please PROVE ME WRONG with facts and figs not what your opinion is,Thanks a 56 year old hard headed Scraper.