I made whole heap of Bronze jewellery recently and after the last firing (when the bronze wasn't fully sintered) I decided to fire them really, really slowly. It worked!
The bangle, which is the thickest piece, was even formed into shape post firing. It stood up to whacking it with a mallet on a bangle mandrel... Hoorah! Success :)
This is how I prepared it:
1) 1 inch of charcoal firing medium in my steel firing pan
2) Bronze bangle and another piece with 1 inch between them
3) Another inch charcoal
4) Some more bronze pieces
5) Another Layer
6) More pieces
7 ) Top up with charcoal, leaving 2/3 inch gap to lid
8) Put lid on & programme Kiln
My Firing Temps & Times:
I used a UK Paragon SC2 Kiln, with a viewing window. The firing pan was slightly raised off the bottom by putting it on my smallest kiln posts. Be careful not to let it touch the Pyrometer at the back of the kiln. I fired it overnight as this is a very, very long firing schedule.
1) Programme 1 - Ramp speed 80 Centigrade per hour
2) Until it reaches 850 Centigrade
3) Hold for 2 hours
4) Remove when cold & sieve out your pieces!
Hope that helps anyone with their own experiments, there are some more close up pictures on my shop blog :)