Q. I would like to know where I purchase the equipment to passivate weld seams on stainless steel, I do not want to dip the parts, I would like to hand passivate. F.K.
A. Through the help of my readers, in the past I have found a tradename product line called Pasa-Jell products. They are thixotropic, so are shaken to thin them for application onto a large metal surface. Upon standing the gel thickens. These appear to have been developed for the aircraft industry where they also deal with large parts they cannot immerse in a tank. I misplaced the information I had on this after first writing about it in my columns in 2000, so looked it up again on the Internet.
The products are made by a company called PRC-DeSoto which are owned by PPG Industries. A distributor of the products is a company by the name of Bergdahl Associates in Reno, Nevada. The particular product you are looking for would be the Pasa-Jell 101. More information on that can be found at www.bergdahl.com/pasaJell_101.htm.