Long or Short

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Rich" <rdjmgmt-at-socket-dot-net> 

I am going to make inductor to help control current to a transformer. I am 
going to use .025 carbon steel wires for the core as I have a coil of it. 
The question I have is, would it be better to fill the center of a 10ga 
plastic spool that is long or a 12 ga spool that is shorter? For the same 
length of copper wire used should the windings be short and fat or longer 
and fewer of them?

Rich