This is some of those "What If" questions from a beginner (I am considering building an airplane cause I already know how to fly them) What If I were to build a "Scratch Built" airplane that utilized a welded aluminum truss structure for the fuselage. What if I were to substitute titanium tubing (of the same size) for the aluminum tubing the plans called for?  I assume that the titanium fuselage would weigh a little less than the same fuselage constructed of aluminum tubing, is that right?  Can the titanium tubing be welded like aluminum tubing? If not welded, could stainless steel gussets and rivets join the members of the titanium truss work together? How strong would the stainless steel gussets be compared to welded joints?  Assuming that the aluminum tubing was replaced by titanium tubing of the same size-how much stronger would be the titanium fuselage?  What is the price difference between aluminum and titanium tubing of the same size?  Does anyone in the EAA ever use titanium tubing for aircraft construction? Your Answers will be Appreciated! THANK YOU!