Try Van's
They used to put a template of the airfoil on the shipping crates. Since I picked my kit up at the factory with a rental truck I had the same problem. Fortunately I bought a set of tip tanks from Farn Reed in Grants Pass, Oregon and they are full chord Aluminum tip tanks that extend the wingspan by 1.5 feet. I was able to trace around them and transfer it to plywood for aligning every element of the wing to conform to the airfoil. I do not know if the RV-4 airfoil is identical to the RV-6 but if it is and he is still in business you may be able to get him to trace the airfoil for you. If you get the airfoil design, you could trace your wing tip and plot the upper and lower camber from where the wing skin ends to where the airfoil ends. If someone with an RV-4 would reverse design the airfoil at the tip adjacent to the aileron and give it to you that would work as well and I would guess that is what you are looking for as a minimum. I got rid of everything like that when I moved. Farn Reed's business is/was "Bladder Buster Tanks, Reed Mfg., 315 Lathrop Lane, Grants Pass, OR 97526.
Bob Axsom
