Bimetallic Corrosion

Today, I've been researching how different metals, when placed together, can in certain environments cause corrosion in one of the metals.

I'm doing this to make sure that the mixture of metals I've chosen for my metal cylinders, and for their substrucure, won't cause corrosion in either. 

For the bimetallic corrosion to happen, there needs to be an electrolyte, like salt water. Rain will also act as an electrolyte, which is why metals used on the outside of buildings have to be selected carefully.

For my indoor cylinders, which shouldn't come in to contact with rain water, the issue of bimetallic corrosion shouldn't be as much of a threat, however I will be choosing suitable metals and using paint and lacquer to protect surfaces from eachother to prevent any problems.

Here's the chart I've created with the help of various websites, which shows each category of metal, their 'anodic index' and subsequently, the difference in anodic index between each category and another category. This difference in anodic index tells me whether I can safely use one type of metal with another.

I owe an enormous THANK YOU to Roger Francis, a leading expert in the field of metal corrosion for his assistance in selecting the right metals for the job.  I'm hoping he'll be able to make it up for the launch of the commission once it's installed.    http://www.rfmaterials.com/

Thanks to:

http://www.zygology.com/productcart/pc/Galvanic-Corrosion-Chart.html
http://www.estainlesssteel.com/corrosion.shtml
http://www.midastech.co.uk/pdfs/TB002-Galvaniccorrosionguide.pdf
http://www.bssa.org.uk/topics.php?article=89
http://www.galvanizeit.org/hot-dip-galvanizing/how-long-does-hdg-last/in-contact-with-other-metals
http://www.roymech.co.uk/Useful_Tables/Corrosion/Cor_bi_met.html