Liquid Penetrant Developer Layer Thickness Regulation

The dye penetrant test only shows you defects that reach the surface. The developer sucks the dye out of the crack and makes it visible. If you apply the developer too thinly, it won't pull the dye out properly. If you apply it too thickly, you'll smear the image and small defects will be lost in the contrast. Spray the developer evenly so the surface is just covered. Let it dwell briefly, then the indication will be sharp.