hey Guy's, Once you can consistently recognize a welding heat the prime success factor usually is the fuel. Metallurgical, high BTU, Low sulfur, low ash coal really is makes a difference. A pure coke or charcoal fire makes things even easier. Whatever you are using, start with a brand new clean fire. Clear you firepot of all the dregs. keep the fire tight not hollow. With welds that really matter I would always make a few buckets of coke first and use that exclusively for my fire. Try to do all your welding first thing before the fire gets dirtied up with clinker and ash. Results will definitely improve.
Glen.