Start your fire with coke left from prev fire, when going well, cover with coal and fines dampened like mud/mortar as the fire burns it will turn into a shell and for delicate welding you can just feed it through the front or you smack it hard with your coal shovel to colapse it on itself and recover with fresh damp coal and fines. In that kind of cave there is not much to cause a problem with a weld. Wire brush the scale from surfaces to be joined. The first 2 hammer blows are critical and make the weld.. they are light blows, not forging blows and they squeeze the weld together, squeezing out the flux and any trash. The first blow should strike the surface of the metal at the same instant the metal touches the anvil, an anvil sucks heat super fast and that can ruin a weld before the first blow. The second blow is on the reverse sideas fast as you can flip the piece and the weld is made. The 3rd and 4th blows are to the ends of the scarf if any (thats why you can sometimes "see" the weld). After that you are cleaning it up/squaring/straightening etc. After some practice it happens as fast as you can strike 4 times and the people watching thinks you must have a magic hammer while you realize the thought and planning it requires.. you learned it, practiced it, programmed it into your reflexes and ran that program at the instant you needed to.. and that you had practiced many hundreds or even thousands of times.. be proud but humble of your skills, none of us learned them without the experiences of others, and forgive me for my preaching to those newer to the forge (I'm pretty old now and all I know can best be attributed to the vast number of mistakes I have made along the way so don't worry about mistakes.. keep some around so you can see your progress and remind you to stay humble).. also it takes a year to learn to start and tend a forge fire.. look at your fire in a year and roll your eyes at the improvement.. also forge a few feet of chain to learn the quickest and build your confidence.
