Hi! Is there a simple nondestructive method to tell whether aluminum is powdercoated or anodized? Coating is black. I tought of rubbing surface with brake fluid (shouldn't harm anodization, should bite powdercoat), but I've heard that some powdercoats are resistant to brakefluid. Electrical conductivity (both are insulators)?. Flame heating (will impair alloys' structure)? A drop of some acid or alkali? Any ideas?
Thanks!