The Gman 476 #2 Posted April 1, 2019 Didn't know that!!!! Share this post Link to post Share on other sites
WVHillbilly520H 10,373 #4 Posted April 1, 2019 (edited) One of my first factory jobs was aluminum extrusion (think tooth paste, Permatex RVT tubes) are produced very similar to the soft drink/beer can...if there was a pharmaceutical like toothpaste or hair coloring we would spray an epoxy coating inside the tube for 1 or 2 reasons (if not both) to keep the product from turning colors from being packed an aluminum case and the other such as hair coloring would actually "eat" corrode it's way through the .005" thick aluminum wall...to check if the internal coating was capable of its intended job was to sample 2-5/hr with Culprit Sulfate acid after 5mins there would be a "rust" formed on the uncoated aluminum surfaces meaning a failure or NO rust was a pass, this fellow just took it a step or two father, thanks for sharing the video. Edited April 1, 2019 by WVHillbilly520H Share this post Link to post Share on other sites