Blue works better for long cuts with the hot
wire tool, on tail surfaces where you are shaping
from a larger profile to a smaller profile over a
short span it cuts the small profile faster than
the large profile and it's impossible to get a
good cut but on the wings it works great and
on the stub wings is absolutely marvellous
only thing is is you get too much wire drag
past 60 inches on the wire.
There is a section of the VARIZE LONGEZE
called Moldless Composite Homebuilt Sandwich
Aircraft Construction by Burt Ruttan that covers
the subject very well
