I had an old rusty set of exhausts for a Yamaha Virago. You can see the before and after results. Of course I polished them up but I did not have to work to get the rust off as it was pretty much gone or disbonded. It has worked great for me on tanks. I use old metal clothes hangars and basically can stick the anode almost to the back of the tank. I just have to keep reshaping it until it is not making contact with the tank. You will know when you have contact as the charger will ping on and off as you have a direct short and overload the charger. Just keep moving the anode around until you are able to isolate it from the tank. I'm about to do one now on a little 1998 honda interceptor VTR250.