I work for a John Deere dealer in western KS, there some modification/improvements that have to be added to some of the air seeders. It consists of 27 hours of cleaning off paint and preping the metal and then after the weld, painting. And also 25 hours of welding. It consists of various positions: vert. fillet, overhead fillet, flat fillet, flat groove, and various thicknesses from 3/16-3/4. Some of our customers want a certified welder to perform these mods, i can weld, but i'm not a welder. What certification would be best for me to satisfy our customers. Thanks a bunch.