Linda, place a fire brick in the forge just under one of the burners.
set the pressure at 5 - 6lbs. you will reach a welding heat in approx 3 minutes,
and the firebrick will protect the floor of the forge from further damage.
I've used NCTool gas since 1996 - and find that the more the floor is damaged,
the more fuel is required to achieve / maintain forging temps.

Added 3 minutes later:

You might want to check the availability of a "re-build" kit for your model.
I did mine in 2002 - with great results. just now looking to rebuild / replace
this forge.