Pickling paste

Pickling paste is an acid paste you apply to the cooled weld seam. It eats away the chromium-depleted oxide layer (the heat tint) created during welding, so that the bare metal underneath is revealed. On contact with air, a protective chromium oxide layer immediately forms again. It's important to use the paste only on stainless steel and rinse it off thoroughly with plenty of water after the required exposure time. If you leave it on too long or don't rinse it off properly, the acid can eat holes into the steel. Definitely wear acid-resistant gloves and safety goggles – this stuff is aggressive.