Wow...

Do not use a grinder and do not sand blast the car at 140 PSI !!!! Even experienced blasters have warped panels...

Some guys swear by dipping and others have seen issues... I would only dip a car if they wash the car very very thouroughly and have e-coat on site... there's nobody near me who does it properly so it isn't even a consideration for our cars...

I don't reccomend soda unles you plan to completely wash the car with a good power washer and a scotchbrite and dish soap afterwards as I've seen many soda blasted cars where the paint simply flakes off after a year or two from not being cleaned properly afterwards...

When we do our cars we sandblast all of the under body, edges, nooks and crannies, frames etc... everything that is solid only, no large unsupported panels. Then we either strip the rest with aircraft stripper and a razor and/or a DA sander with no more than a 120 grit disc... you can use an 80 to get through tough spots but don't brake all the way through to the metal with those coarse grits. This process is extremely easy when all you have left to do are the big flat surfaces..

I've been told plastic media is good and won't warp the larger panels but I haven't used it yet simply becuase I recycle my sand/glass grit over and over again and don't want get it mixed in with that media... attached is a picture from the old shop, the way we used to do it... a $300 blaster and a tarp is all you need if you have a good compressor and a little bit of property...

Media blast is the best - period...
Second to that (from my repeated experience) is the following: Chemical strip.

Buy the following items from your local auto parts store...lowes...home depot:

1. A few cans of aircraft stripper
2. (Thick) Rubber Gloves
3. Respirator - or industrial breathing mask
4. Safety glasses
5. Several CHEAP paint brushes
6. Several cans of high quality self-etching priner.
7. Cheap plastic trash can
8. a few CHEAP metal putty knives for scraping of different widths.

--->
Paint/Apply the aircraft stripper on your car (in one direction as the instruction say) and let it work for several minutes....after a while the paint will start to lift and bubble.

Once it has lifted all it's going to (10-15 minutes) scrape the old paint into the cheap plastic trash can.

Only remove the paint that you will have time to througoughly CLEAN with WATER...DRY...and prime before going into the house.

I personally like to work an area about the size of a hood....or fender and door...etc..

Once the paint has been removed (or most of it), I take a water hose and wash and rinse very very good with soap and water. Then I dry it with a clean towel (after its dry, I wait a few minutes) then applu the (SEM brand self-etching primer) very thick. Any metal that you miss will be rusted in the morning.

You just really need to make sure you wash the metal really good before priming.

If you take your time and just work a few square feet each day (30 minutes at a time) you will have the whole car done in a few days.

NOTE: Be sure to remove any waterproof watch you are wearing before working around the aircraft stripper...I have ruined (2) nice water proof watches doing this. The TOXIC vapors coming from the Aircraft Stripper somehow destroys the little rubber seals in my watch that make it waterproof.
CRAP ! I didnt notice they were damaged until they starting fogging up when I was in the shower, and I didn't really know what caused it until the 2nd one was ruined...

I still prefer blasting, but it also has it's drawbacks.

Good luck

not to hijack the original question but what is the next step after blasting? Vacuum and blow off any remaining media? Metal prep with zinc phosphate solution? For floors and under carriage would POR 15 be a suitable coating before paint (not a concourse restoration)?