Recently I received 2 stainless steel tanks and the mounting brackets on them had been broken off. I had a local machine shop weld the brackets back on to the tanks. Unfortunately, they did not have the ability to passivate the welds. These tanks will be exposed to weather, so it was important that they be treated. I purchased a Passivation Test Kit and some Wonder Gel. I used the test kit on the new welds and just for fun I tested a small stripe on the factory weld. The new welds tested positive for needing passivation, but what surprised me was the small area on the factory weld that also tested positive. I applied the Wonder Gel as instructed and rinsed it off after 20 minutes. When I later tested the areas again, they passed the test! Both products were quick and easy to use. I recommend them highly if you work with stainless steel. Photos below.
After cleaning a groove from a grinder was discovered.
For more information about our line of Derustit products for passivation and pickling of stainless steel, please visit our product page.