I went to Yamaguchi's class and he is a master fillet-brazer as well as master frame builder in general, who knows what else he does. He is one of the most interesting people I have ever met and working with him for 2 weeks was the experience of a lifetime. With that said, he will teach you to braze, you practice it his way just about every morning but I would start practicing before you go just so you can get comfortable with the torch and get a feel for brazing in general and working the puddle. If you have a knack for art with your hands and have him as a teacher you should be fine but its much easier when you have a master next to you who can tell you what to do, continueing to braze afterward is when you will start to get your fillets dialed in. I would like to work with him again to learn some more, every morning I couldn't wait to get there to see what he was gonna do, great all around guy, class act.