I do all of my cutting, welding, and dent repairs (excluding filler) prior to blasting.
As a hobbyist, I can't get it all done at once, so there is bare metal exposed to the elements throughout the process. This is not a problem since everything will be blasted and epoxy primed once I have everything done. Once everything gets back, epoxy primed, I can begin high build primer and filler work on top of the epoxy without worrying about rust.
I never understood why anyone would do the blasting first on a rust bucket, unless they had the ability to knock out all of the repairs in a day or two.
Carl
