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<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> Just a few thoughts about using the Titanium rod. FROM http://www.pemnet.com/design_information/galvanic.html Since TI is at the lower end of the chart and Stainless Steel is 4 to 5 levels above I would think the electronegativity difference would yield very little corrosion potential. Aluminum is at the top end of the chart. Aluminum forms a protective oxide with the air that prevents further corrosion. Oxygen and Nitrogen would be way, way off the top of the chart. FROM http://www.deutschetitan.de/eng/profi/kb21.html Contact corrosion in titanium materials In the active condition titanium is a relatively unnoble metal whose standard potential at <1.75 V lies between those of aluminum and magnesium. However, already at room temperature titanium forms a firmly adherent and dense passive layer on the surface which characterizes its corrosion properties. In oxidizing and neutral media, as well as in reducing media containing amounts of oxidizing components (inhibitors) which allow formation of the passive layer and inhibit its destruction, titanium displays high corrosion resistance. Due to this passive layer there is no significant difference in electrochemical potential between titanium and the corrosion resistant 18/8-CrNi steels, Monel and Hastelloy. The risk of contact corrosion on surfaces of roughly the same size in seawater and chloride-containing solutions for example is therefore extremely slight. However galvanic contact of titanium with magnesium, aluminum, copper and their alloys can result in increased corrosive attack on these partner metals. Deutsche Titan, Nov. 2000 FROM http://www.webspinners.futura.net/apurdy/periodic_tabl.htm Using the periodic table you can select an element and look up the electronegativity. This will give the galvanic potential between the elements and the tendency for corrosion to develop. The electronegativity of TI is 1.54 and the FE is 1.9. For reference Oxygen is 3.44, Nitrogen is 3.04, Aluminum is 1.61, and Carbon is 2.55. Corrosion potential is the difference between the electronegativity of the two metals. Example: 1.9 (FE) - 1.61 (AL) = 0.29 (Do you have the aluminum elevator brackets with the press fit bearing and steel bolts?) 1.9 (FE) - 1.54 (TI) = 0.36 Slightly greater than AL / FE 3.44 (O) - 1.90 (FE) = 1.54 (Makes rust) 2.55 (C) - 1.61 (AL) = 1.06 What does all this mean?? For myself, I would use the Ti rod with a light coat of grease. Just my 2 cents. Ranny LML website: http://www.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com.