Under ASTM D3359 method B, a cutter scores a lattice of 6 or 11 lines each way through the coating to the metal, pressure-sensitive tape is pressed on and ripped back, and the grid is compared with rating pictures from 5B (no flakes removed) down to 0B (most of it gone). It is fast and cheap enough to run on first parts every shift. A poor result points at pretreatment or undercure.
First piece passed cross-hatch at 5B, go ahead and run the rest of the order.
Also heard as
- crosshatch
- tape test
- cross-cut test
Related terms
Pretreatment
The cleaning and chemical conditioning a part gets before powder, which decides most of its adhesion and corrosion life.
Impact test
A test that drops a weighted punch onto a coated panel and checks whether the film cracks or lifts.
Undercure
A film that did not get enough time at temperature to crosslink fully, so it looks fine but performs poorly.
Recoat
A second coat of powder over a cured first coat, used to fix rejects or build a multi-coat system.