Picked up a 4' X 12" sheet of 0.040" 6061-T6 from Trident. Will be first used to make vertical spar doublers.
I also rummaged with a sales rep in the storage area in search of a 0.125" plate for the vertical tail horn. I found a 6" X 48" piece that was most likely headed for the scrap heap so it was generously donated as a "SAMPLE". This is the kind of customer service that will keep me coming back for all of my materials.
Unfortunately they, and everyone else I've contacted locally do not carry the 0.016" sheet. I sent ZAC Tech Support a message asking if I can substitute 0.020" since it is readily available. The thicker material can be used if I don't mind the weight penalty. The extra 0.004" on a 4' X 12' sheet amounts to 2.7lbs so based on the amount of aluminum required I should plan on an extra 2lb in parts. I don't want weight creep to start this early in the build but I just can't see paying double to have the thinner material shipped to me.
The 3/4" X 3/4" X 0.093" angle is also a non-standard size. Looking for resources on this as well.
