VDI 3958 Blatt 13:2012-11

Subject of the guideline is the test of resistance of varnishes, which are supposed to be used in an environment with humid-subtropical or tropical climate (tropical suitability). Those varnishes are regarded whose functioning or life time is mainly defined by the conservation of the required features of their surface or areas close to their surface. It concerns amongst others high gloss varnishes, especially those for automotive industry, for which an impairment or even loss of the designated optical decorative features might lead to the loss of the whole product concerned (high loss of value).The guideline describes both the test of tropical suitability under natural environmental conditions (outdoor weathering) and the test of tropical suitability in test chambers (artificial weathering), in which the specific environmental situation is simulated. It addresses manufacturers and user of varnishes for outdoor use as well as operators of weathering stations and test laboratories.