Merry Christmas, I came across this article and it looks interesting. Something to try. As with any acid or alkaline solution, wear protective gear, especially eye protection, do the work outdoors, and closely monitor the progress.
http://tttg.org.au/php/ArticleView.php?id=28
Many different acids can be used to remove rust from iron and steel. Citric acid has an advantage over some other acids, because it is less caustic, not as hazardous environmentally, while remaining effective, cheap (although not as cheap as old battery acid). The chemistry is fairly simple, the rust (iron oxide) is solubilised by the acid (ammonium ion is also acidic) and the citrate ion coordinates to the iron ion forming soluble iron citrate. (more)
http://tttg.org.au/php/ArticleView.php?id=28
Many different acids can be used to remove rust from iron and steel. Citric acid has an advantage over some other acids, because it is less caustic, not as hazardous environmentally, while remaining effective, cheap (although not as cheap as old battery acid). The chemistry is fairly simple, the rust (iron oxide) is solubilised by the acid (ammonium ion is also acidic) and the citrate ion coordinates to the iron ion forming soluble iron citrate. (more)
