Inductance Calculations for iron core

Looking for some help with figuring out how to build my own current limiting
inductor for my pig. Please don't tell me "you can do it
I already know that (I currently use a Lincon 225A AC welder as my limiter.)
I'm just one of those "Build it yourself" type of guys :)

What I am looking for is a guesstimate, or even the formulas to compute
the inductance knowing the approximate cross section area. My plan is to use
a bunch of rebar tie wire I have here, cut to about 20" lengths, to fill
a 2" PVC pipe. This would give me an open core with about a 1.6 square inch
cross section.
Estimated inductance per turn would be best, I'll probably use #10 THNN wire
for about 6 TPI. (roughly 110 turns end to end)

The OD of the PVC is actually 2.4" if that helps.
(and if someone could refresh me on the formula for reactance, I wouldn't
either :) )

Michael Baumann
Coiler, Homebrewer, Nerd. mycroft-at-access1-dot-net