need advice fast= phosphoric acid prep over sandblasted metal, now flash rust

[stang32]

ok, so I have been sandblasting the interior, dash, inner frame rails, rear seat back panel on my vert, which is on the rotisserie w/no floor in it. .i have been blasting for 3+ weeks, well 3+ saturdays, & i have a small amount of flash rust, since it has taken me so long to get primer on it. it was suggested to me that I should lay down some phosporic acid to remove the flash rust & any unseen rust so I got the etch & prep from Home depot. the directions say:

FOR TREATING METAL FOR PAINTING (Phosphotizing)
1. Remove any oil, grease, & dirt from surface.
2. Dilute 1 part product with 3 parts water in a plastic container.
3. Apply product with a paintbrush, spray bottle or pump-up sprayer to metal. Surface may turn gray/white.
4. Thoroughly rinse with water after 15-30 minutes.
5. Wipe off any loose powder that forms. Paint treated surface within 48 hours of application to prevent formation of new rust.

I did so & when I wet the metal down with water rinse, i immediataly got flash rust over top. of most of the areas treated. I have since resprayed the etch & let it sit, it has been about an hr since I di this & I am trying to decide were to go to from here.
in top of this crap, now it is starting to rain so looks like i am done for the night.
yes the car is outside & yes it is covered.

any thoughts?
my instinct is to let it dry & shoot epoxy primer right over the phosphate but really do not want to do this job again so I want to hear what others have to say
thanks guys

 

[Midlife]

Instead of of water wash, I wipe the dry residue off, then just before painting, clean the metal with wax and grease remover.

Instead of washing the metal with water, did you try a simple damp rag and wipe the metal down?

 

[stang32]

no, I didnt, although after the initial panic past, I did wipe down some areas & they looked ok,. I am just concerned that I cant prime over the acid w/out neutralizing it.

 

[jmlay]

after I blasted my car I pressure washed it & you can only imagine the amount of flash rust after. THe metal prep took care of it instantly. I did not rinse mine after applying the metal prep. I it will be sanded before painting.