I went a step further on the windscreen. My propane tank sits inside a 30 gal steel drum with a inner sheet metal liner giving about 1" of clearance around the tank. The drum to liner void space is filled with fiberglass insulation (paper removed). The tank sits on some bricks with a weedburner firing into them. The indoor range scrap we melt has bits of target cardboard and wood that acts as a reducing flux when heated in the covered tank. Its much nicer not being 'cooked' on the warm smelting day by an unshielded melting tank.