The stronger the etchant the more metal it eats away and the faster it works. That can be enough to erase a crisp grind line or deform a plunge cut. How much you have to grind to remove an etch depends on how deep the etch went, with FeCl it usually doesn't take much. Also, the more powerful etch will etch all the types of metal in the billet very quickly so there could be less contrast than with a slow etch where the most sensitive metal etches first and you can stop the etch before the other metals are significantly affected ...
|