help with heating up file

[Shadow44]

here is my attempt at my first knife which failed due to using mild steel, then i side tracked to making a knife from a 7mm thick file which was a 3 hour grinding process ... I'm posting pics as i go...
so to anneal a file i build a small 2 brick forge and inserted 2 propane burners with no luck
I can not get the steel to turn color even after 20 min..
all pics can be seen in the original post....

WHAT am i doing wrong for heat treating?
do i just need more heat?

 

[bluebutcherbird]

I'm assuming these propane burners are large, unless you mean youre using propane torches? Your biggest problem could be a lack of insulation. If you can't seem to get it hotter after 20 min, you're probably losing heat somewhere. I'd suggest trying coal and a hairdryer for something simple. Or heating only the edge with your two burners outside the forge. Takes a while but it will work.