Idea to raise heat

[dtec1]

hey guys so as i have said before i just got a new propane forge. i was playing around with forge welding a stack and see if i can get a pattern out of it. but anyway i notice with this new forge it has trouble getting the steel stack to that real yellow color it kinda hovers right on the border of bright orange and just a lil bit of yellow. i actually sent the guy that made this forge a email a lil while ago cause i have seen one of his vid's and it seems to get yellow a little bit easier so maybe its me i am probilly missing something. but this is a round forge with a inside diameter of 5 in and length of 10 in. so i was thinking if i dont need all that space for this project say i added some pieces of fire place brick so maybe instead of it being 10 in long i add brick so its like 6in or 7in long. or even if i cut the brick to the right sizes and stacked them up the sides so maybe i could bring the diameter from 5 in to say 3 in. So in my mind (m mind doesnt always translate to reality well) if i add these bricks it would bring down the volume of the inside of this forge and therefore the burner has less space to heat up and it should be able to get hotter. Yes? No? like i said this kinda works in my head but my brain doesnt always get along with the real world. any thoughts on this or any thoughts at all on how to get a lil more heat out of the forge would be appreciated. THANKS GUYS

oh one more thing maybe some one can clear this up what is the best way to tell if the steel is at forge welding temp....some people say when it gets real yellow others say when the flux is dancing around but both of those are different i found flux to dance around at bright orange not real yellow.