I have a question on temper vs weld strength on 2219 aluminum.  I want to conduct a study where I weld a butt joint on 2219 material with one pass and test the weld strength.  Then I want to make another sample where I have several heat inputs.  The purpose of this is to analyze how much the mechanical properties suffer after several heat inputs.  The material condition I want to test if 2219-T62, but suppliers are having a hard time finding that temper.  They do have t81 temper.  Will the temper make that big of a difference in resulting weld strength after a test like this? 

Thanks