D3806-19 – Standard Test Method Technical Guide

ASTM D3806-19a, the Standard Test Method of Small-Scale Evaluation of Fire-Retardant Paints (2-Foot Tunnel Method), establishes a bench-scale procedure to evaluate how a coating protects its substrate and assesses its comparative burning characteristics. Per Section 1.1, it evaluates the flame spread over the surface when ignited under controlled conditions, establishing a basis for comparing surface-burning characteristics without specific consideration of all end-use parameters. Values are stated in SI units as the standard (Section 1.4).

📐 Specimen Geometry and Panel Preparation

The standard test method utilizes a 2-foot (610 mm) tunnel apparatus. Test specimens are prepared