I make a beehive fire and poke a hole in the front. put the stock in and bring to an orange heat. Pull out, brush, apply borax. Put stock back in the fire. When you are looking at the fire in the beehive you will see three shades of yellow. Heat the iron, using a low air flow, until it is the same as the of the three colors you see in the fire. The surface of the steel also looks oily. When you pull the stock out it should be smoking pretty well (that's the Borax burning off). Use lights hits down the center of the area to weld. Brush at orange, apply more flux, repeat process for entire surface to weld. I also find I get a stronger weld if I work the welded area at a near welding heat. Working it cooler than that seems to cause the welds to fail for me.