  A thorough study of the effects of mass loss on internal and surface
abundances of A and F stars is carried out in order to constrain mass loss
rates for these stars, as well as further elucidate some of the processes which
compete with atomic diffusion. Self-consistent stellar evolution models of 1.3
to 2.5 M_sun stars including atomic diffusion and radiative accelerations for
all species within the OPAL opacity database were computed with mass loss and
compared to observations as well as previous calculations with turbulent
mixing. Models with unseparated mass loss rates between 5 x 10^-14 and 10^-13
M_sun/yr reproduce observations for many cluster AmFm stars as well as Sirius A
and o Leonis. These models also explain cool Fm stars, but not the Hyades
lithium gap. Like turbulent mixing, these mass loss rates reduce surface
abundance anomalies; however, their effects are very different with respect to
internal abundances. For most of the main sequence lifetime of an A or F star,
surface abundances in the presence of such mass loss depend on separation which
takes place between log(Delta M/M_star)= -6 and -5. The current observational
constraints do not allow us to conclude that mass loss is to be preferred over
turbulent mixing (induced by rotation or otherwise) in order to explain the
AmFm phenomenon. Internal concentration variations which could be detectable
through asteroseismic tests should provide further information. If atomic
diffusion coupled with mass loss are to explain the Hyades Li gap, the wind
would need to be separated.
