Media (Soda) Blasting?

[James McClure]

After soda blasting, pressure wash metal. Take your time and do a good job of it, then wash with soap and water and pressure wash it again. Prep surface for etching, then etch and prime. OR, after the last wash, let it surface rust just a little, towel off the rust and paint it with P.O.R. or something of a similar nature. I've been using POR for a long time. If it's good enough for the Navy, it's good enough for me. Prime over the POR and paint from there. DON'T sand the POR!! Get the primer on while the POR is just a little tackey, but mostly dry. (if you can touch the POR without it sticking to your finger it's about right.) Spray the primer and let it cure overnight, then start the prime sand, prime thing till you have a smooth base for the overcoats. When it's all done, let it cure for a month or so, then wet sand and buff out. Let that sit for another month before you apply any polish or surface sealer. I paste wax for the first coat, after that I just use a wipe on wipe off wax. The paste wax is a tough job, but done right, it will last a long time under the wipe on wipe off stuff. jim

[Thumpin455]

If you can get it blasted by a professional who has worked with vehicle sheetmetal it is usually worth the expense, particularly if you are only doing it one time and not planning on more vehicles. Some will go so far as to lay down a coat of primer for you after blasting to prevent flash rust. Its easy to spend a like amount on the tools and equipment needed to do the blasting yourself, but if you plan to do more than two vehicles, it can pay off in the long run to buy the stuff you need and lean to do it correctly and safely.

Doing it yourself:

Soda wont remove rust or hard stuck on stuff like bedliner/undercoating, it takes paint off really well and wont harm trim, rubber or glass. It creates less heat so panel warpage is minimized with soda, so its ok for outer sheetmetal surfaces. Soda is a one time use media, you cant sift it and put it back in, once its been run through the blaster its done. Clean up is with water, pretty easy but still a mess.

The more aggressive media, red garnet, black slag, and silicon sand will easily remove rust and heavy deposits, but they will do serious damage very quickly to sheetmetal. Only use the heavy stuff for frames, door jambs, and parts of the vehicle that wont be seen when its assembled. If you blast the 6 coats of paint off your box with sand, chances are you will have very friendly box sides, the waves will be everywhere and surfers will try to ride your truck. Its like a continuous shotgun blast everywhere you go, so you want to use an angle that glances off the metal rather than perpendicular to it. Avoid blasting into holes or between two panels, like a cowl or the roof of a cab. media will sift out for years if you do that.

I still sand down all exterior sheetmetal with a DA rather than risk warping a panel or making it so wavy I need 2 gallons of high fill primer on each piece to get it flat. You can still make waves with a DA, but you have to be pretty thick headed to do so.

Get the biggest air compressor you can afford and fit in your shop, you will find it much easier to run air tools and they are a good investment. You will find other uses for it, and when you need it its there. How often do you hear someone complain about how the compressor they got is too big? It wont work as hard to keep things supplied, mine will run with a DA and shut off 30 seconds after I stop sanding, I use less electricity that way because it doesnt have to run for half an hour to catch up.

Blasting in a garage is not a smart idea, you need plenty of room to do it. Media gets everywhere, in the outlets, light fixtures, all sorts of places you wouldnt think of. You can use a tarp around the work area, but it still makes a ton of dust and the sand will escape. Heavier media can be swept up, sifted and run again. I use some steel mesh from a screen door wedged between a 8"-6" stove pipe reducer and a short length of 6" pipe. Even sand has a lifespan for blasting, you can only run it though a few times before its rounded off and loses its cutting effect, not all of it, but its vastly reduced.

If you are going to blast you really should take some precautions, a quality hood, eye protection, a quality respirator not a gauze mask, and at least a jacket and gloves to protect your skin.

[Thumpin455]

It makes short work of the really crusty areas that normally arent seen.

It starts like this:




And ends looking like this:



The black parts are new metal, this old Mustang is the most labor intensive project I have ever started. Most people would have just parted it out and scrapped it, but I have an affliction that prevents me from doing that. I always believe I can fix it, no matter how bad it is... Its really a sickness...

Its been bare metal for two years while the patches are welded in.

[msgross]

I used coal slag on my frame, outside. I had to use coveralls, gloves taped at my wrist, hood, respirator, goggles, boots taped as well...

It still sucked and I was cleaning it out of my skin for a few days! I am all for ablasting cabinet or sending it to a pro.