I worked in two body shops over the years. All the vehicles I've worked on came out best using corn cob. It's agressive enough to clean the surfaces(though not like sand, glass beads, etc.) but doesn't generate much heat which warps sheetmetal. I've even used it to clean the inside of electric motors. The bad areas can then be spot blasted to remove rust but usually those areas are cut out before installing patch panels anyway. Baking soda is a good medium also but usually more expensive. Whatever you use, follow up with a good primer A.S.A.P.!

Rob

 

and use gloves when handling bare metal

 

I would definitely have whatever you can work on first blasted, rather than the whole thing, no sense it all sitting around blasted unless you work real quick or have little work to do. Media blasting will remove all paint, body filler and rust down to bare metal, but that bare metal will be very susceptable to rusting almost instantly. Just touching it with bare hands will produce rust prints overnight, a sweat drop will rust in a couple hours. If you are going to work on a piece within a couple of days and you have dry storage then handle the piece with rubber gloves and give it a phosphate wash. If the parts are going to sit more than a couple days, and/or your shop is humid then give the parts a washing with prep solvent and nylon pad or at least mineral spirits and pad (wearing rubber gloves!) then shoot them with a light but complete coverage of a catalized primer surfacer, wrap them tightly in plastic and seal air tight with tape. When you are ready to work on the part, sand off the primer with 80 grit paper wherever you do welding or filling, then shoot with a full coat of primer and sealer. Cover again and put away until you are ready to assemble and paint. Remember regular single part primer is porous and will rust thru if exposed to moisture.
The magazine pix of complete vehicles in bare metal look really cool, but they are in a heated and dehumidified shop and were still likely freshly sanded for the pix.

 

Anyone try Soda Blasting? done with water, no distortion!

 

AFAIK Soda blasting is done dry, but it is very gentle, will not remove old filler. Other blasting media that works well is walnut shell or walnut shell mixed with plastic media.
You should never use sand or glass beads on body panels (some very experienced or lucky blasters may get away with it, but not on any panels of mine thank you!).

Re sanding: yes, painting is the easy part the real work and quality is in the prep. Even the guys at Earl Schibe can turn out a good paintjob if you do all the prep work yourself first.

 

Personally I think the soda blasting is another conspiracy by the baking soda people. It'll help dough rise, it'll remove odors, it brightens white clothes, it settles an upset stomach, and now it removes paint and rust!

Actually, the guy that media blasted my cab also offered soda blasting, said it was originally developed for the Statue of Liberty, when she got her overhaul. The sodium bicarbonate was gentle enough it didn't affect the copper at all and hardly any heat is generated. May check into it if I ever feel weak and start another truck project.

 

I've often polished tarnished silver and copper by scrubbing it with a baking soda paste. When I was a kid it was quite common for people to brush their teeth with a salt and baking soda mix. Baking soda does a great job of cleaning the corrosion off battery terminals, and for getting kamakazi bugs and road film off windshield!

 

if my previous post misconstrued anyone...the blasting shop should also primer the finished pieces{ may cost extra) before they leave their shop. thus blast/prime then when you get it back into your garage then start the bodywork. the primer will allow you to see the dents a little easier too.

 

I don't know too many blasters that will prime the pieces after blasting, I'd be happy if they would phosphate wash it to keep it from surface rusting before you got it home.

 

I had mine bead blasted 2 years ago here in vegas cab and doors cost me 400.00. only three places in town did blasting and the other two didn't want to do it. cab and doors came out very nice. I had to primer it myself but replaced all four cab corners before I primered. I presently work at sin city motorworks and we just had the blaster do a hummer frame for 500.00. So I expect the price has gone up a little for a cab. fyi.

 

I had my cab, doors (removed) grill, valance and several small pieces soda blasted. commercial blaster does this work and it is a wet process... so no heat...no warp.

It leaves a very fine grain to the metal, not nearly as agressive as glass beads. The soda will leave a film on the surface that will retard rust if kept in a decent waterproof shelter for several weeks... mine sat for about 2 months before we got it in primer.

BUT... before you prime you must neutralize the soda with a vinegar rinse. As you apply the vinegar you'll see what appears to be flash rust but as you wash the vinegar off with water it's gone ...and nicely saved in your driveway and in your clothes...

Another thing is that the soda accumulates EVERYWHERE. Every nook (what the heck is a nook ??) cranny, joint, seam... under the dash.. inside the doors... EVERYWHERE... the best bet is to air blow as much as possible before the rinse... beat on the panels with the heel of your hand while blowing (wear appropriate safety glasses).. and blow some more... when you think you have it all out.... blow some more and you find more.

We used about 15 gallons of white vinegar with brushes, pump sprayer, scotchbright pads, screwdrivers, fingernails, toothpicks, ice picks, rags and copious amounts of cussin .... it was hot that day and we used some beer also.

I'm very pleased with the result... after the rinse and dry cycle... lots more air blowing and a heat gun in the cracks and crevices... we shot it inside and out with Dupont Europrime primer... we found NO rust from the cab sitting for that several weeks...

My price ?? free... (don't hate me cause I have friends, hate me cause I'm beautiful) but it did take the guys doing the work several hours. It will take most thin filler out... but there were some 'wads' of bondo over 3/8" thick that it only dulled the edges on... that was ground out later...

later
John