Slinky for 10 Meters and other bands when...

If you can put that up between two masts on the roof, you have room
for a real wire dipole for each band you want to operate. I think you'll
be happier with that. If they don't fit between the masts (or hanging
from one mast as an inverted vee) then run the center of the antenna
as far and as straight as possible, then bend the ends to run out to
corners of the yard or whatever you have to do to make them fit.

It is true, folks HAVE used slinky dipoles before. And with a tuner and
balanced line, I'm sure it radiates. The resonant frequency will depend
on how far out you stretch it and how the coils are arranged. Here
is an example: say that you tie the end off to a particular length and
bunch all of the coils by the feedpoint - this will make a center-loaded
antenna and you can get a good idea of the resonant frequency by
calculating the coil inductance (from the number of turns, diameter and
length of the coil) and the total length of the antenna, since the few
turns in the rest of the antenna won't have much effect. Now if you
move all of the turns to the middle of each side of the dipole you have
the same inductance, but the antenna will resonate at a higher frequency.
If you move the turns to the end is will resonate even higher. So by
moving the turns around on the wire you can vary the resonant frequency
by some amount - perhaps as much as 2 : 1. But you may find that,
unless the Slinky is made from bare metal so you can short turns together
to remove them from the circuit, it is difficult to get it to resonate as
high as 10m. And moving the coils around isn't a convenient thing to
do whenever you want to change bands, especially if it involves
climbing up onto the roof and lowering one or both masts.

I think you'll be a lot happier with wire dipoles.