What is the primary purpose of this standard?

To simulate natural weathering (sunlight, rain, dew) in a compressed timeframe to evaluate the durability and degradation of paint.

How is the test duration determined?

The duration is not fixed in this base code; it is specified in the individual product specification code for the particular paint or coating.

How are the results evaluated post-exposure?

By comparing the exposed panel to an unexposed control panel, looking for defects such as loss of gloss, colour change, chalking, cracking, and blistering.

IS 101 Part 4/Sec 1

: 1988

Methods of sampling and test for paints, varnishes and related products: Part 4 Durability tests Section 1 Accelerated weathering

CurrentSpecializedTesting MethodMaterials Science · Painting, Coatings and Surface Finishing

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This section of IS 101 details the methods for testing the durability of paints, varnishes, and related coatings using accelerated weathering techniques. Engineers and material scientists use this test to rapidly simulate the effects of long-term environmental exposure, such as sunlight, rain, and humidity, on painted surfaces.

Specifies methods for assessing the resistance of paint films to accelerated weathering conditions.

Quick Reference Values

Standard test panel dimensions150 mm x 75 mm

Mild steel panel thickness1.25 mm

Tinplate panel thickness0.315 mm

Practical Notes

Accelerated weathering results are highly comparative; they provide an estimate of relative durability but do not translate to an exact lifespan in real-world outdoor exposure.

Proper preparation of test panels (cleaning, application method, and drying time) is critical for reproducible results.

Evaluation should be done strictly against an unexposed control panel to measure defects like chalking, blistering, and colour loss.