Dry film thickness: the measured thickness of a coating after cure, read with magnetic pull-off or electronic gauges on steel and checked against the specified range for each coat. Inspectors take spot readings in a set pattern per area, commonly under SSPC-PA 2, and thin areas get extra coats while thick ones risk cracking, trapped solvent and poor cure. Applicators control it while spraying by checking wet film thickness with a notched comb gauge.
DFT on the second coat averages 4.5 but the edges are under 3, stripe them before the topcoat.
Also heard as
- dry film thickness
- dry mils
- film build
Related terms
Stripe coat
Extra coat brushed onto edges, welds, bolts and corners to build thickness where spray runs thin.
Mud cracking
Network of cracks like dried mud in a coating applied too thick, typical of inorganic zinc and waterborne paints.
Holiday
Pinhole, void or bare spot in a coating that leaves the metal underneath exposed.
Pull-off adhesion test
Test that glues a dolly to a coating and pulls it off to measure how strongly the coating sticks.