Does salt spray testing predict real wear on zipper sliders?

Q: Does salt spray testing predict real wear on zipper sliders?

It ranks finishes better than it predicts service life. Salt spray is an accelerated, constant, aggressive exposure that does not reproduce the cycle of wetting and drying, abrasion, hand contact and detergent that a zipper actually sees. A finish that survives 96 hours may still discolour in a few weeks of coastal use, and a finish that fails early is almost certainly a real risk.

Use salt spray as a screening and batch-consistency tool: compare plating baths, thicknesses and suppliers under identical conditions, and set a minimum that correlates with your field returns. Add a wear or tarnish test, and a wash test where detergents are involved, to cover the mechanisms salt spray misses. Keep the test conditions identical between comparisons, otherwise the ranking is meaningless.

State the method, the hours and the assessment area in the specification, and treat the result as one line of evidence beside field performance, plating thickness measurement and supplier process control. A supplier who can explain a failure mode is more useful than one who merely reports a number.