Rust on your vehicle is almost unavoidable. Whether you need to fix rust or you’re trying to prevent new rust from forming, this post will cover all the ways to combat and prevent surface rust.

What is Rust

Rust occurs when the iron in steel comes in contact with water or moist air, causing oxidation. Salt will speed up this reaction so areas of the US near the coast or where salt is used on icy roads will experience worse rust symptoms than drier climates. Rust is permeable so a surface layer of rust will not protect the metal underneath it and eventually the surface rust will progress to a rot which will, over time, consume the entire metal. Rust will most commonly form where paint gets worn away and water gets trapped up against bare metal such as under plastic trim pieces near the wheels or side skirts, under carpet or where two body panels meet.

How to Repair Surface Rust

Surface rust does not penetrate very far into the metal underneath it so its much easier to repair then rust rot. If you have really bad rust that has weakened the metal, you’ll need to cut that area out and weld in new metal. This post will not cover repairs that extensive. The key to repairing surface rust is to remove as much oxidized metal as possible and starve the remaining particles of oxygen and moisture.

Our van right after we bought it. You can see some rust on the floor near the back doors.

STEP 1: To repair surface rust you must first remove the ALL the visible rust from the area. An angle grinder with a flap disk or wire wheel is a good tool for the job. Don’t start grinding away at rust until you have all the materials ready to repair it that same day. Always wear eye protection when using an angle grinder.

Angle grinder
Flap disc
Knotted wire wheel

Remove any hardware around the rusted area such as door latches or clips.

Floor near rear door after the angle grinder
Side step after grinding rust

Be careful if you’re using a cut off wheel as you can quickly grind too much metal away and be left with a hole. If the angle grinder disc diameter is too large to get into the tight spots, a Dremel and sanding drum might work better. The key to this step is to remove every little bit of rust you can see. Think of it like a cancer that if left will spread. If the angle grinder wire wheel does not work for you, then try chucking one of the regular wire wheels below into your cordless drill. These come in different sizes, shapes and stiffness so you can find one that fits in any space.

Wire wheels
Dremel sanding drums

STEP 2: Scuff up the original paint surrounding the area you ground down. This will make sure the new paint will stick to the old paint really well. I recommend using 120 grit sand paper.


POR-15 System

The POR-15 system consists of three parts. A cleaner, a neutralizer and a rust preventive coating. I’ve used it to restore an old motorcycle frame with great results so I decided to use it again on our van because I think its the best way to fix rust. My one piece of advice if you’re going to use POR-15 products is to follow the directions very closely. POR-15 comes in 1 Pint and 1/4 Pint kits depending on your project size.

STEP 3: Use the POR-15 cleaner and de-greaser to thoroughly clean the area. The surface should be keep wet 10-15 minutes then rinse thoroughly with water and allow the surface to dry. Don’t allow the cleaner to dry onto the surface, it must be washed away with water.

STEP 4: Apply POR-15 Metal Prep to the bare metal surface, keep wet 10-15 minutes then rinse thoroughly with water and allow the surface to dry. It is important not to allow POR-15 Metal Prep to dry on the surface prior to rinsing with water.

STEP 5: Wearing gloves and a properly fitted respirator is recommended when applying POR-15 Rust Preventive Coating. It is recommended to apply two thin coats. Apply the first coat to the properly prepared substrate, then apply the second coat when the first coat is almost dry, slightly tacky to the touch. If POR-15 Rust Preventive Coating is applied too heavy, brush marks may result in the finish. Do not apply this product if the humidity is above 70%. If the humidity is too high the POR-15 will dry too quickly which may result in small bubbles in the finish. A top coat is only required if exposed to direct sunlight.

Cargo area after applying POR-15
Cargo area after applying POR-15

You can see that I covered ever single little area where the factory paint had been scratched with POR-15. Now is your chance to fix this stuff because it will be covered up forever once you start insulating.

Painted over the black POR-15 with white spray paint
Painted over the black POR-15 with white spray paint

I used white Rust-Oleum spray paint over the POR-15 to match the vans original color. Looks good as new.

Although the POR-15 products are more labor and time intensive then regular paint, I believe it’s worth it. This stuff dries SUPER hard, it feels like glass and because it worked so well on my motorcycle, I have no doubt I’ll never have rust problems in those areas again on my van. While you could just spray paint over the area what I like about the POR-15 metal prep is that it neutralizes any remaining rust that was left behind so it cant continue eating the metal under your new paint.


Rust Reformers & Converters

You can buy products that claim to neutralize rust and convert it back to metal. I personally have never used them so cannot speak to their effectiveness but I thought I should mention them in this post. If you did not want to go though all the effort that POR-15 is, maybe you could try one of these converters and then paint over the area. Reach out to us if you have any experience with these products, I’d love to learn if they work.

Preventing Rust

Spray on Bedliner

Bedliner is commonly called Rhino or Raptor liner and dries to a very hard textured surface. Its common to see the wheel arches and side skirts of trucks painted with the stuff. Some go as far as to paint their whole vehicle with bed liner. It could be used as a barrier coat on the floor inside your van before you start building. You can find DIY bedliner in a spray can at any hardware store but for best results it needs to be applied by a professional.

Rubberized Undercoating

People either love or hate this stuff. It sprays on like paint but dries to a rubbery texture. The main concern with this product is that it does not breath so any moisture that gets trapped under the coating will eventually cause rust. The best area to used this product in on PLASTIC wheel wheel liners, not the frame of your vehicle. My suggestion is to avoid it all together.

Rust Inhibitors

These are spray on products intended to be used on the undercarriage of your vehicle. They are popular in areas of the country where salt is used on the roads in the winter. They also starve existing rust of oxygen and moisture, slowing its progress. You do have to reapply these products every year or so for best results.

Touch Up Paint

I carry two colors of nail polish in the glove box of our van, white and black. Every so often walk around your vehicle and check for new paint chips especially on the hood and fenders and touch up any areas you find. You can find perfect color matched touch up paint for your vehicle if you want.

Hope these tips helped you fix rust in your campervanvan. Next step – Sound deadening and insulation. Subscribe to our mailing list so you don’t miss out on more content like this.

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