ASTM D610:07 pdf free download – Standard Test Method for Evaluating Degree of Rusting on Painted Steel Surfaces.
3.2 The degree at rusting is evaluated using a zero to ten scale based on the percentage of visible surface rust.
3.3 The distribution of the nest fl classified ra spot rust. general rust pinpoint rust or hybrid rust
4 Interferences
4.1 The visual evanigdes that are part stthis test method and the associated nistgrude scale cover only rusting evidenced by visible surtax rust.
4.2 The use of the visual ersamples requires the following cautiotes:
4.2.1 Sonic lintshes are stained by rust. This staining assist not be confused with the actual rusting involvesi
4.2.2 Accumulated din or other material may make accurate determination of the degree of ousting diflicult.
4.2.3 Certain types at deposited dtrt that contain iron or con compourm&s may cause surface discoloration that should not he rrustaken t,r corrosion.
4.2.4 Failure may vary over a given aret Discretion must theeelswe he used when selecting a single rust grade N raM distribution that is to he reptesentative of a large area or structure, or ta subdividing a suucsure for evaluation.
4.2.5 The eokw at the finish canting should be taken into account in evaluating surfaces as lailures will he more apparent on a finish that shows color contrast with rust, such as used in these reference standanis, that on a similar color, such as an goal Li5idmf finish.
S. Prnerdnsre
5.1 Select an area to he evaluated.
5,2 Petennine the type of rust distnbsttion using dehrrinons in Tafile I and sisual esamples in Fig. I, Fig. 2_and Fig. 3.
5.3 Estimate percentage of surfa’e area rusted us.ing the visual evamples in Fig- I. Fig. 2. and Fig. 3 or SSPC.VIS 2. a both, by elecimnic scanning techniques or other method agreed upon by contra.ling parties.
5.4 Do not consider flow of conosion products onto the surface at intact coating that in, “rust bleed” or stainingi as part at the ssalre area rust It nay be helpful to wipe the surface with a damp cloth to renusse the rust bleed before evaluating.