Everybody! Please chime in with your inputs on this.
My input: IF you are building a specific pattern into a "can", widening it once getting the can fully welded isn't an option... the reason is that the pattern will quickly distort to beyond recognition.
The route I take is that when I am reducing "the square", I seek to end up with the square being just slightly larger then the width of the blades I intend to produce from it. The "extra" is to allow for grinding/milling off all the can walls.
In other words, if I intend to build hunter size blades, I will forge the square down to something in the 1 3/8" range, and once the "can" is completely removed, it will end up in the 1 1/4" range +/-, which is the width I most often use for hunters. I usually make big "cans"..... and when forging the can down, will often forge a portion to 1 3/4" square for bowie sized blades, and then some into 1 3/8" square for hunters, and maybe even some to 1" square for folder blades and/or scales.
The idea of building canister Damascus is to create a specific pattern or scene, and preserve it throughout the forging process, and into the finished blade/knife. That means much of has to be thought through ahead of time. Just have to change your way of thinking through/conducting the process.
Now.... to widening in a press. Your press is the 12 ton "H" frame... right?
This is one of the big drawback to an "H" frame design, and a plus for a "C" frame design. On most "H" frames you can't get to the dies from the sides. The only answer I have come up with is to build mild drawing dies, with the ends of the dies facing the front/back of the press opening. And even then it's not an easy chore to gently press in different places across the billet...unless you use stop blocks. Then you of course have to change out dies and in order to get things flat again.
It might seem silly, but this is one of the place were I couldn't live without my air hammer!
HEY! Maybe you could talk the Mrs into an air hammer too? (I had to try!
)