There are several places in the plans that allow the use of the MK319BS rivet in place of the 426 flush rivets. Well I was reading another builder site and learned of a narrow head Cherry Max (CM) rivet that can be used as well. The CM rivets are expensive but strong and a structural rivet. I find that mandrel of the CM rivet breaks off slightly above the rivet head. I have read you can shave or sand them down. The MK319 rive mandrel breaks off below the surface, but you can fill this in and once pained you will not be able to see much difference.
I deiced to set one of each and took some pictures. What I learned is the CM once set is taller than the MK319; this comes into play at the trailing edge of a control surface in that once one side is set it might be impossible to set the second side. I might be making a bad comparison since the MK319 is usually only going through 2 layers when called for in the plans. I did this test because I plan to set my elevator "riblet" web facing out which will require blind rivets.
I hope this helps anyone who has wondered like me about CM rivets and the ones Van’s sends on the kits.
