If you are using a quality epoxy primer (I like SPI) plus have some sort of "tooth" in the bare metal, there should be no need of etch - you have to get any rust off tha bare metal first, so that will give you that "tooth" to bond to the metal. Also, and my opinion only, most Eastwood products are overpriced (to pay for their advertising) and seldom no better, and often worse then their normal professional counterpart - they're a Central PA cpmpany and haven't even made the NSRA York SR Nationals for 8-10 years