site for galvanic action rusting referring to fig1 the steel stock 10 is pre treated and galvanized according to prior art techniques while the zinc coating is malleable the steel stock then passes through a shot blasting machine 12 where zinc pellets impinge upon the surface of the zinc to remove the u03b3 layer and to roughen the u03b4 layer a machine suitable for this step is a wheelabrator shot blaster model wcrc 4 subsequently while the treated zinc coating is still malleable it passes through a coating zone 14 where a top coating is applied typical liquid coatings suitable for purposes of the invention comprise polyamide epoxy primers and aliphatic polyurethane finish coats the coatings can also comprise powder coatings collectively these coatings are well known in the art and need not be described in detail other than the fact that the treated steel stock passes through the coating zone while the zinc coating is malleable the coating step per se is well known in the prior art that is the color of the coating its composition and thickness are determined by specification the following illustrative and non limiting example exemplifies the process of the invention steel stock i e an 8 39 i beam is galvanized as shown in fig1 the u03b4 and u03b3 layers of the zinc coating are approximately 4 6 mills and the outer u03b3 layer is approximately 2 mills and has a substantially smooth outer surface 16 see fig2 a the steel member travels continuously through the shot blasting machine 12 at a rate of 2 ft min pure zinc pellets impinge on the zinc surface to remove the u03b3 layer and to treat the u03b4 layer 18 see fig2 b the pellets typically.