Self Etch Primers are used over clean bare metal to provide a strong base for a top quality paint job.
Eastwood Self-Etching Primers
Self-Etching Primers contain an acid which etches the metal to provide a strong bond. Use self etch primers on steel, stainless steel, and aluminum panels. After applying self etch primer, you will typically follow up with a urethane primer to provide a high build surface which can then be block sanded smooth.
Other Eastwood Primers