Given that stealth is the main strategy used to keep people from asking questions or causing problems, it is important to have a vehicle that looks, sounds, and drives fairly normal. If you are starting with an older used vehicle, there is a good chance that the exterior might need some love. I’d recommend replacing or painting anything on the exterior that has any rust. Rust and oxidized paint are two big eye sores that make a vehicle stick out unnecessarily. Worn lettering from a previous owner or company also ranks up there.
Because of this, you may want to paint the vehicle. Paint jobs often cost thousands to have done professionally. Usually, this is something that is not undertaken by a DIY person, but it is quite doable. Especially if the vehicle has a work vibe to it. For the work truck vibe, you don’t need the paint job to be flawless, just clean and even. It needs to look okay from a distance.
Automotive paint is not the same as most other paints. It is a two part catalyzed paint similar to epoxy. You could use tractor and implement paint or rustoleum enamel, but for a little bit more money, you can just buy actual automotive paint. Whichever paint you use, I’d recommend using white for the body and black for the rims/ wheels. This is super generic and will help the vehicle blend into almost any parking lot.
The paint that was recommended to me was Axalta Imron, or formerly Dupont Imron. It is one of the most common kinds of paint used on commercial trucks. It apparently has a high resistance to stone chips and environmental conditions like salt. It is a topcoat finish meaning that the color is also the finish coat. It is a catalytic polyurethane finish with the paint and activator . I have used many types of paints and finishes over the years and I have never seen anything quite like this. This paint is typically applied professionally using sprayers, but it can also be applied using a roller by using a rolling additive. It is super sticky and will adhere tenaciously to probably any surface it touches. The coverage is pretty good, but white will most likely still require two coats to get total coverage. For reference, I was able to get about 500 square feet per gallon coverage. Plan on needing two coats.
Surface Prep
Be sure to wear an N95 dust mask respirator and safety glasses when sanding any existing paint finish. Depending on the existing condition of your vehicle, you may need to do a bit of work to prep the surface for painting. Stepvan bodies are typically made from aluminum. Aluminum doesn’t rust per se, but it does corrode. You will want to sand / abrade any corrosion before you paint. The corrosion under the paint is a chalky powdery white and is not solidly adhered to the metal underneath anymore. You will want to remove any corrosion so that the new paint will not flake off eventually with the corrosion. If you have a typical vehicle made from steel, you should be fine to sand and repair any surface rust. Anything more than surface rust will be a problem. If there are actual holes in steel panels due to rust, you will be spending quite a bit of time trying to fix and fill those. Good luck with that. I’d recommend finding a vehicle that has minimal rust or surface rust only.
Sanding down to bare steel in an environment with any decent amount of humidity will cause the bare steel to rust again pretty quickly. Overnight dew will cause it for sure. Because of this, you need to do this on nice sunny days when rain is not expected. You also need to reprime those fresh bare metal spots almost immediately. Bare steel can be brutal, even with just hardware like hinges and bolts.
Some vehicle lettering and logos are painted on instead of vinyl lettering. Vinyl lettering can be taken off with a heat gun. The remaining residue or surface underneath can be sanded to remove any surface inconsistencies that might leave letter ghosting through the new paint. Painted vehicle lettering absolutely must be sanded and feathered at the edges so that ghosting doesn’t appear. This can be time consuming and laborious.
You can use multiple tools to sand the existing finish. A 120 grit nylon wheel in a corded drill works well for aggressive sanding and irregular shapes. I found the wheel style worked way better as opposed to the cup style. Use a nylon wheel on an aluminum vehicle as a normal steel wire wheel will create problems with dissimilar metals.
Whenever you are painting over an existing finish with a new finish, you typically want to sand the existing finish to help adhesion of the new finish to the old. If the previous finish is not rusted or corroded and just needs to be scuffed for the new paint, use 1/4 sheets of 220 grit sandpaper and sand by hand. I was told specifically not to do this by multiple people and the internet, yet it worked great. I tried multiple times to use a sanding block, but it just seemed ineffective and didn’t work as well as sanding by hand. I suppose if you are going for a showroom finish, hand sanding might be bad news. I recommend 3m Pro Grade Precision 9 sandpaper because it has a sticky back that makes it easy to use. You may need to go down to 180 or 120 if the 220 just isn’t scuffing the finish well enough.
Sanding any previous lettering or surface imperfections can take quite a while. You may also want to use an orbital sander with 120-220 grit discs. The coarser 120 grit may be needed for smoothing and feathering bigger surface imperfections. You need to be careful with the orbital sander though as it can QUICKLY cut through the paint and leave sanding marks which then need to be sanded out again themselves. If the orbital sander still isn’t feathering the edges, you may need the wheel drill.
I would note here that because the new paint will be rolled on instead of sprayed on, some surface imperfection is tolerable. The rolling nap itself will leave a slight orange peel texture that will hide some surface imperfections. You will probably also find that it is super easy to accidentally sand right down to the metal on corners and such by accident. Be careful and try your hardest not to do this. That being said, the Imron paint is so tenacious, it probably doesn’t matter if that tiny little edge is bare metal. Just makes sure to cover it well with paint. That goes for really any small imperfections that go down to bare metal. Take some time and prime the bare metals spots in general, but if there are some spots that just keep sanding through, it’s not the end of the world. A good example here would be rivet heads. Even one good swipe with sandpaper can accidentally show bare metal again. Don’t worry, the paint will take care of it.
The sanding is done once all flaky rusty corroded surfaces are smooth metal and the general paint has been scuffed. All surfaces should be sanded to 220 grit at this point. You might have large areas of bare metal at this point depending on how much sanding had to be done. If you have any small dents or dings, you may want to fill them with Bondo. Things like deep scratches or sharp dents can be smoothed over using Bondo body filler. Dent repair is beyond my abilities and the scope of just painting. Feel free to investigate that on your own if you need to.
All of this sanding creates a ton of dust that basically cannot be avoided. Sanding dust will find its way into the vehicle. Realize that you will need to do some serious vacuuming and cleaning once the whole process is done. Or if you can, take care of the paint first.
Technique
You will want to remove as much hardware and trim as you can before painting. Things like door handles, side mirrors, rear lights, headlight trims, grill etc. Some stuff you won’t have easy access to, so you will need to tape it up with masking tape. Tape up rubber window seals, lights, and hardware. Try not to leave the tape on too long though as it can leave a sticky residue.
I rolled both the primer and paint on my van. I was quite skeptical about this at first as I thought it would look really bad. I can say that it has turned out surprisingly good for being rolled on. In fact, most people that see it are fairly impressed that I painted it myself, and with the overall finished product. If you can do a decent job rolling paint in a house, you can probably do a decent job on a vehicle.
WARNING. Both the primer and paint I used are nasty professional grade products. You need to wear protective gear, specifically a respirator. A respirator is disposable and is only good for roughly 40 hours of use. Do not put it on until you are ready to start mixing, and take it off and store it in the air tight bag when you are done. If you leave it exposed to air, the charcoal filters will be used up and you will need a new one. In order for a respirator to work, you must have a freshly shaved face. When it is really working, you should not be able to smell the products at all. If you can faintly smell anything, you don’t have a good seal. Also, do not get any product on your skin or in your eyes. Wear safety glasses, rubber gloves, and be fully clothed. I primed and painted my van outdoors which mitigated the fumes substantially. DO NOT prime or paint indoors with these products without a fresh air supply respirator.
I used a 4.5″ x 3/4″ roller for painting the entire van. I did this because of the short pot life of the primer and the paint used, and the fact that the smaller roller is easier to control and get clean results. I’m sure it took more time doing it with a small roller than a bigger roller. A shed resistant knit 3/8″ nap was used on the roller. Given that the catalytic finishes set instead of dry, each nap is one time use only, which also includes a one per mixed pot use. Both the primer and the paint need to be mixed with an activator prior to application. Because of this, you can only mix up a small amount of product at one time before it gets too hard to roll. The primer sets especially quick. I typically mixed up 16-24oz of primer or paint if I knew I had a big area to cover. If it was less, I tried to guess the amounts to avoid wasting very much. When you are finished rolling a batch, remove the roller nap and wipe down the roller frame with rag. Both the primer and paint set pretty solidly so you want to clean off any product from the frame before it sets.
The mixing is done in plastic quart mixing cups that you can get from the automotive paint supplier. You pour the main product into the cup and then add the appropriate amount of activator to the mixing cup. You then mix the product until is completely mixed together. The ratio of activator to main product is different for both the primer and paint. Given the way the primer sets, you can gently squeeze the mix cup and crack the set primer to remove it and reuse the mix cup. The Imron takes a while to fully set, so you will need a fresh mix cup for every batch.
Primer
Any bare metal should be primered first. Honestly, the Imron would probably adhere to the bare metal, but I don’t recommend that and I didn’t chance it. I used USC Eliminator Polyester High Build Primer. I used this because it can be used direct to metal on aluminum without any extra steps or prep. It rolls on quite thick and sets ULTRA quick. You can probably sand this stuff in like an hour or two after applying it. It is a catalytic primer that needs to be mixed just like the paint. The amount of activator required for each batch is tiny, like milliliters. I used a disposable measuring cup that comes with medicines like Nyquil as the measuring cup for the activator. The ratio is 16oz of primer to 7.5ml of activator.
Wipe down the area to be primed with warm water prior to priming to remove any remaining dust. Mix up a batch of primer and roll it on. I found that it often needed two coats of primer over bare metal. This is not a problem because it sets so quickly. You don’t need to sand in between coats. Apply as much primer as is needed to cover your bare metal completely. The primer goes on thick so it doesn’t go as far as you think it might.
Once it is fully set (a couple hours probably), hand sand the primer with 120-220 sandpaper. Hand sanding allows you to keep from digging in too hard and cutting through to the bare metal again. You will still probably do this, but try to limit it as much as possible. Sand all of your new primer so that the finish is fairly smooth. Once again, the paint will have some texture to it so it doesn’t have to be smooth as glass.
Paint
Wipe down the area to be painted with warm water prior to painting to remove any remaining sanding dust. I painted my van in multiple sections. I found that overlapping seams didn’t appear to be a problem, but even still, it is best to put the seams at a natural spot where they would be less noticeable like a corner or a straight body line. Mix up the paint and roll it on similar to the primer. The paint is much thinner and goes a lot farther. Axalta Imron requires a rolling additive if you want to roll it on instead of spraying it. The ratio of paint to activator is 4 to 1. I commonly mixed up 20oz paint : 5oz activator : 6ml of rolling additive. The rolling additive was also measured using the medicine cup.
Imron takes way longer to fully set, like 1-2 weeks. Because of this, it is way more forgiving for overlapping, even from batch to batch. You can over lap a previous batch and it should look okay. Just like any other paint job, paint from the top down. It is dry to the touch by overnight, but the daytime high temps need to be at least in the 70s otherwise it just doesn’t get warm enough to set.
I actually had really bad weather when I painted my van. I was dodging rain constantly. It seemed as though as long as the paint had a couple hours to set, the rain didn’t seem to bother the fresh paint. I did however have a situation when it rained like 10 minutes after I finished painting. That did mess up the paint. The rain streaks were quite visible. I still haven’t repainted or fixed it yet, as you can’t really tell unless you get close. There were also a ton of bugs, flies, and spiders everywhere as I did this on some property that was quite rural. All of those bugs drove me mad when I was painting it, but in the end didn’t really matter very much. You can’t really see the imperfections due to the bugs at a normal distance.
When it was all done, I probably spent 3-4 weeks worth of labor sanding, priming, and painting my van. You can save quite a bit doing this yourself, but understand beforehand that it is quite a bit of work.