sand blasting

to help with the question. Yes you can blast a hood and not warp it. BUT not for the first time blaster or an industrial blaster who does train cars all day long. .

lots of false info/wives tales out there on blasting so ill condense it down to MY reason why stuff warps. DIY people are sold rocks for media and are shocked when those rocks peen the surface and warp it. "fine" media to industrial supply places is usually around 30-60 grit. in my blasting world 30-60 is for gravel boxes and swimming pools. 100-200 is what i use for sheet metal

soda and walnut. great for paint removal. not great at rust removal Wet is 100% a dust suppressant and now you have shitty mud to clean out where you cant get to. wet blasting isn't for cars, its for concrete and still makes heat.

under hood bracing is easy to blast. where the bracing meets the underside hood skin is where the warpage happens. hitting it at a low angle (like 15 degrees) you can get under the brace and work the paint and rust down that way rather than a 45 degree and hope the metal doesn't move. its still tricky and not a fool proof method. (70-80psi at the nozzle)

if i get a hood that i am not 100% sure i wont damage i will do the bracing underneath, edges and 6" or so on the the perimeter topside and let the shop finish the rest (or work down 90% of the paint and primer and leave finishing to the shop)

that being said. in 15 years and hundreds of cars i have replaced stuff three separate times. (i warp it i replace it, no questions asked) all three times were hoods. third time was a couple months ago on a jeep wagoneer hood. i was so careful and didn't see the warping happen. it was the bodyman who found it.

so yes, there are blasters out there that wont warp the hood but its tricky. if its a rare hood you could always get it dipped as well and save the possible chance of damage.

not sure if that helps but gives you a bit of insight.