Qualification of shop primers

Shop primers are coating materials which serve to provide primary products such as sheets, sections or also component segments / subassemblies with temporary protection from corrosion during the storage or the further fabrication in the factory, in the shipyard or also on the building site. 

Shop primers are often also designated as fabrication coatings or colloquially simply just as welding paints or primers.

If it is then necessary to weld these primary products and/or components any further together, the overweldability of the utilised shop primer must be guaranteed according to DIN EN 1090‑2 which has come into force and, in Section 7.5.1.1 for EXC1 and EXC2, demands proof that the coating material does not influence the welding process. The procedure according to DIN EN ISO 17652‑2 in combination with DASt 006 provides this proof. A welding procedure qualification test with fabrication coatings is demanded for EXC3 and EXC4. We carry out these qualification tests - get in touch with us!

With its testing laboratory accredited for this purpose, SLV Duisburg carries out the tests according to DVS 0501 or DIN EN ISO 17652 for them as coating material manufacturers or as users when they want an independent test report and assesses the results. Gas detection tests can also be carried out as an option.

The overwelding of organic coatings, e.g. shop primers, gives rise not only to the formation of pores in the weld deposit but also to the absorption of hydrogen. Particularly in the case of high-strength and ultrahigh-strength steels, hydrogen input into the weld deposit may lead to delayed cracking (hydrogen embrittlement). Therefore, it is recommended to determine the hydrogen input too during the overweldability qualification of coating materials.