  We investigate the localization of electrons hopping on quasi-1D strips in
the presence of random magnetic field. In the weak-disorder region, by
perturbative analytical techniques, we derive scaling laws for the localization
length, ${\xi}$, of the form $ \xi \propto \frac{1}{w^{\eta}}$, where $w$ is
the size of magnetic disorder and the exponent $\eta$ assumes different values
in the various energy ranges. Moreover, in the neighborhood of the energies
where a new channel opens a certain rearrangement of the perturbation expansion
leads to scaling functions for $\xi$. Although the latter are in general
quantitatively wrong, they correctly reproduce the corresponding $\eta$
exponents and the form of the scaling variables and are therefore useful for
understanding the behavior of $\xi$.
