| abstract |
A shop primer composition comprising (i) fillers and pigments, at least 25 wt % of which have conductive properties; (ii) zinc powder in a weight ratio of between 1:6 to 1:1 to the fillers and pigments; said zinc, fillers and pigments being milled to a sufficient fineness; (iii) anti-settling agents; (iv) optionally, thickening agents; (v) a silicate-type binder, in an amount such that the weight ratio of the SiO2 content of said binder to the zinc, fillers and pigments is of from 1:4 to 1:16; and (vi) solvents. When using this shop primer composition, the welding properties are improved and the health hazards during welding are reduced, without having to remove the primer layer at the welding area. The primer coatings are compatible with the welding techniques generally used in the heavy steel construction industry, including MIG/MAG welding in 3F position. |