most of my customers are going soda blasting for there cars these days..
if you do go sandblast mark out all the flat areas so he does not do them..example...centre of roof... side panels where windowless and bonnet and lower tailgate..lower gate may be ok coz its a smaller area but you dont wanna risk it...just paint strip the areas not blasted..

as for priming,most blasters will prime for you at extra cost..either etch or both..

if you do get them to leave it bare metal you really need to prime it straight away to 24 hours depending on the climatic conditions..longer if your in a desert.;)

etch isnt a sealer and neither is acrylic primer...if you were gunna leave it for years i would throw a thick coat of black or whiye acrylic over it...or any mismatch colour thats cheap..

also make sure you seal your repairs when you do them straight away.

DISCLAIMER...i am not a tradesman and i taught myself in conjunction with annoying people that were tradesman back in the 70s and 80s which was very much acrylic painting.so this is just advice on what i have learnt and done...

if you go into the hq sandman thread you will see a pic of my hq and its in high fill which is porous,that pic was taken in 2001 and it was handstripped and etched,primed and highfilled in 1997.. i was told and had been outside in a lean too facing the ocean which was about 2k sitting on top of a hill for about a year b4 i got it..
you can see surface rust bleeding thru in those pics.where the etch prime is but where it has been painted is still clean to this day..


blocker,go back to the guy with the sandman and ask him what he used to paint it with so he can wash it off...i am presuming he has just painted acrylic straight over the bare metal and he will use thinners to wash it off as it wont get a real good bite in the metal..