They are both good prducts and work as advertised... ACF50 seems to
make less mess... If you are happy with X, I wouldn't change... I was
just making the point that the exposed metal surfaces in an assembled
airplane are not the major site of corrosion, it is the fayed joints,
and coating them on the outside with paint will not protect them... I
spoze one could spray Variprime and also use ACF50, seems redundant
though...

denny