I am using an "insta-forge" that is working fine for me using a similar style torch. I believe the Bernzo8000 puts out the same as my TurboTorch.

What I am reading is that your forge is a simple brick and cement, with no layer of actual insulation to prevent the heat from radiating outwards. Combine this heat loss with the added heat sink of a piece of steel for the floor, and you probably are not generating enough heat too raise temp as fast as you are loosing it. How big is that steel flooring?, does it stick outside of the forge when you are working? Let the forge run full on for 15 minutes before putting your blade in. If the forge is not up to temperature, by then, you may need to add a second (or larger) torch.
here is a link to my forge just so you can see it if you care to look.
http://straightrazorpalace.com/forge...rst-forge.html