I bought some new tail gate chains for my unrestored and patina'd 1950 3600 that came all plated and shiny - did not look right on my truck. I keep a pvc pipe on end outside the shop with a glued on pipe cap at the bottom and one to remove at the top filled with dilute muriatic acid for dissolving mill scale from steel bars prior to machining or shaping with a belt grinder. I dipped the chains in there for about 30 seconds and they came out a nice subdued french grey kind of color. They look okay on the truck now. The acid is handy stuff for derusting old tools and other iron or steel objects. It does not freeze either best that I can tell.
