I am new to the welding process and am learning through this forum, books, and trial and error. I am using an oxy/acetelyne set-up. My question is as follows. I have a truck receiver that has the hitch stuck in it. Yes, the hitch pin was removed. I even tried chaining it to a tree to pull it out. What is the best way to heat up the receiver to loosen the hitch for removal? What type of tip and size should I use. Your help is appreciated.