frame and tub...necessary to get off rust?

[Gary Nafziger <naffy@netins.net>]

with the advent of por-15 and such chemicals......is it really necessary to
blast frames and body tubs??  whats wrong with a good cleaning maybe with
steam to get off all grease and oil.......some light blasting or scraping to
get off loose rust......and then cover with Por-15......realizing that all
rust throughs should be patched........

has anyone done this with a frame off restoration??.......(skip the removal
of crud down to bare metal) 
                Gary, Frances Nafziger
                Box 25
                Wellman, Iowa 
                naffy@netins.net