I recently purchased a 70 Charger R / T that came from California. The car was Plum Crazy Purple from the factory. It looks to have never been repainted. Purple was known for peeling off when these cars were new. It looks like the paint peeled and burned off the car, and someone sanded off what was left, and just left it out.in the weather. The car is nearly rot free, but the panels have a fairly heavy surface rust coating. I am wondering if maybe dust less blasting or something like evaporust would work to remove the rust. Then what would be the best way to prep the surface for body work and paint?

I'm in same situation with a 62 sport fury. No rot just surface patina from Texas. I was told to use Muric acid in panels but haven't started yet. Curious to see what suggestions come in.

DA sand it with 60 or 80 grit and acid etch with rust-mort or equivalent then epoxy prime.

Best? Have it blasted. Second best? Wire wheel it, sand it, then epoxy prime it.

Muriatic acid will remove the surface rust , even deep pitted rust, but be aware it is a very dangerous chemical that can KILL you or cause injury. First off DO NOT USE INSIDE ANY BUILDING , the fumes will KILL YOU!!!!!!!! and also the fumes will cause anything that is metal to corrode. If you decide to use it do it out side when the wind is blowing away from your house or garage , no wind? get a big fan as the fumes will not allow you near the car. Keep your kids and pets away. Use heavy gloves and eye protection, have a water hose on hand to rinse off the metal and you if you happen to get any acid on yourself. Also note that the acid and rust will stain your driveway . You'll need baking soda to neutralize the acid, then another chemical to neutralize the baking soda as the baking soda will react to paint and cause lifting. All in all it will work but you better be careful, I have did a whole car that had surface rust with deep pitting with good results. Google is your friend .

Listen to this! Muriatic is bad stuff. I used it to remove CAD Plating from some parts. Did it outside with heavy gloves, face mask, and wind blowing away - I still felt like I was handling radioactive lava!

Muriatic acid you buy now is duluted down to 5% . Like anything that's works its bad in a sense, how else would it work. Phosphoric acid, numerios names it goes by, viniger-lemon mix is good for "surface" rust, but the deep pits needs a harsh liquid to get down into those pores. Most blasting can't get in there. Use silly puddy to make dams for using the liquids ( evaporust, muriatic, ect) has to be submerged to work. A couple drops of Joy detergent will thin out the mix. If you had a swimming pool that's not being used, could do the dc charge and washing soda, annode-cathode thing, works very good. Everything has a risk, research it before using.

I haven't started to strip the rust yet, but it is more of a heavy even surface rust, but not deeply pitted. Out west they don't have the humidity that we have here, so I don't think the car is deeply pitted

You're going to have to sand it a number of times during the paint job, sand it now to give you an idea of what the surface really looks like.

R.

What's the preferred media type to blast exterior body panels with?

Soda ash or walnut shells and only by someone who knows what they're doing. Heat the panels up and you'll warp them. Your body man will love you or you'll want to shoot yourself trying to straight a heat warped panel. Most places prefer to dip cars now. It's much safer and removes prior plastic body filler.

Ive had good luck using baking soda for lightly rusted areas, and havent had an issue with warping. I was using a smaller siphon feed unit from harbor freight though

Regarding muratic acid, Ive only submerged parts in it, never applied it with a rag. It works wonders but you have to watch how much time you let it sit because it will begin to eat metal. Throw a bolt in overnight and watch the threads disappear.

That would be my suggestion... and what I have done. DA and/or wire wheel, treat the surface and epoxy prime.

Acid, if not neutralized, can keep eating the surface after the paint goes on. Sandblast can be very messy and get media in all kinds of hard to clean places.

The muriatic acid had me scratching my head. I suppose full strength it's pretty nasty but you can by it over the counter at a pharmacy .05% for use in baby's eyes! I'd work very carefully with lower concentrations.

I sand and then muratic acid. Flush the panel with water while the acid is still wet. I then follow up with ppg metal prep. Get a respirator the fumes will sneak up on you even outdoors. Buy it at the hardware store.

That is what I did on the roof of my own 70 Charger. It had a vinyl top that was mostly shredded when I got the car. This was in 2002 and no signs of rust coming back.

I used a sponge with a scrubby on it to apply the acid.. When muriatic acid is applied to rusty metal it will foam up green till the rust is eaten away. Surface rust will dissolve quickly,deeper will take longer. It is best to sand off as much rust as you can first. I used those plastic woven disc from Harbor freight that fit a 4 1/2" grinder. They will quickly remove the paint, bondo and surface rust . You can not leave any rust on or in the metal surface or it will come up under your new paint. Another thing to keep in mind , when stripping metal bare, moisture in the air or applying water will cause flash rusting within minutes, so you have to be prepared for that also. As stated above buy some ppg metal prep

I use the 3M wheels on a die grinder or 6" grinder. Wire brush on a drill for the really deep pits, then treat with rust convertor. Then sand with 180 on a DA, and bodywork from there. Thus far it's held up on several cars, going past 10 years for one of them.

If it were mine, it would get dipped. Only way to make sure all of the rust is removed and no more metal removed or damaged.