Gab Travelling | Travel Blog

repairing rust on a van ford econovan feature

DIY: How to Easily Repair Rust on Vehicles

DIY Projects, Van Build

Buying a used vehicle comes with a lot of unknowns, for my vehicle it was rust. When I first purchased my van the rust spots seemed small. Later the truth came out when I realized the seller had sprayed paint over the spots so I couldn’t tell how bad it actually was.

As my trip up Australia’s east coast progressed, so did the severity of the rust. Thankfully, repairing the rust didn’t take long and my van is now good to go.

First, I thought a welder would have to fix the rust. Before feeling doomed, I found out there are easy—and more affordable—ways to fix rust, even if it’s already created a hole. 

I think of rust as a cancer, in most cases it can be scraped off, but unless it’s completely gone, it will just return. And without taking care of the rust it will continue to get worse. It’s also important to fix it right the first time. This saves from tearing off more metal and losing more integrity of the vehicle later on.

This post contains multiple ways to remove and repair rust from a vehicle. These DIYs include rust repairs with no holes, small holes and larger holes (up to 2.5cm/1 inch). Also included is all the materials needed and product options!

  • This was the worst rust spot on my van, with a hole going through the metal.
  • vehicle rust before
    This is how the major rust spots looked before they were fixed.

Rust Repair Products

Depending on the hole size, many auto stores sell rust repair kits. Online there’s also reliable options, delivered straight to your house (or equally convenient pickup locations!). The kit I used on Ebay is the Isopon P.40 Kit, which is for holes up to 75 mm/3 inches. Amazon has 3M Bondo Rust Repair kits, which is a similar proces to the Isopon.

Since my hole was bigger than 25mm I went with a fiberglass repair kit. If the hole is smaller you can use the same kit, or just a body filler solution. The fibreglass kit has an aluminum mesh that becomes moulded into the rusted area with the fibreglass glue. Then, a body filler covers up the rest of the area. 

If you have some materials from the kit or only need a small repair, then you may only need to purchase body filler and/or body adhesive patches to repair holes.

A few things to keep in mind before repairing rust with these methods. Even with a fix, it may not look seamless, but it will be a lot better than before. Especially depending on the location of the rust.

I’m really happy with repairing the rust on my van, it turned out a lot better than I thought it would. The area is slightly raised and a bit rough, but it’s only noticeable up close. For the second concern I could have fixed it by adding more layers of body filler to make it smoother. All of these products have a time limit as they set/dry quickly. This makes it difficult to make it smooth the first time around.

  • repairing rust after
    After fixing the rust
  • There’s still some minimum imperfections from the fix, but I prefer this over the rust!

I recommend to do this in a workshop if possible and not while it’s very humid or rainy. These weather conditions can affect the dry time and quality of the paint and the other solutions.

Repairing Rust Without Holes

Materials

Method

  1. Start by removing all rust, either with an angle grinder or sandpaper. Use safety glasses if using an angle grinder, and I keep gloves on during the entire process. I used an angle grinder with a metal sanding wheel, but an 80 grit metal sandpaper works as well.
  2. After removing the rust, clean the area well. Use a degreaser for stuck on grime. Otherwise the paint, primer or rust converter used next won’t hold properly.
  3. (Optional) If it’s not possible to remove all of the rust, use a rust converter to prevent the rust from spreading. Follow to the products instructions before moving on. I like the 3M brand rust converter. To make sure it doesn’t get anywhere other than the rust I put it on with a Q-tip for the small spots.
  4. Apply two coats of primer according to package and paint, if necessary. I found the body paint gives a really good smoothing effect so the rust fix is hardly noticeable.

Repairing Rust With Holes Smaller Than 25mm (1 Inch)

Materials

Method

  1. The begin repairing the rust, start with removing all rust. Either with a metal brush or sandpaper. I used an angle grinder with a metal sanding wheel, but 80 grit metal sandpaper works as well.
  2. After removing the rust, clean the area and remove any remaining particles. Use a degreaser, if necessary. Otherwise dish soap should work fine.
  3. (Optional) If it’s not possible to remove all of the rust, use a rust converter to prevent the rust from spreading. Follow to the products instructions before moving on. I like the 3M brand rust converter. To make sure it doesn’t get anywhere other than the rust I put it on with a Q-tip for the small spots.
  4. Mix body filler to package instructions and apply. There’s a four minute window to fill the hole and make it smooth. Use the plastic card or gloved fingers for this. Beware of air bubbles, this is where the plastic card comes in handy to push it down. It’s okay to leave the filler protruded at this point because it will be sanded down still.
  5. Wait for filler to set, according to package instructions.
  6. Use the 150 grit sandpaper to grind down the mound of stiffened filler so that’s it’s just about even with the rest of the vehicle. Use the 180 grit sandpaper to smooth the area.
  7. If the spot is smooth enough, then it’s ready for paint, sand another 25mm around the area to roughen up the current paint with the 150 grit. Cover the surrounding area to prevent off-spray from the paint. If the area isn’t smooth enough, repeat steps 4-6 until continuing.
  8. Then apply primer and paint to the area according to instructions. Once dried the area should look consistent with the rest of the vehicle.

Repairing Rust With Holes Larger Than 25mm (1 Inch)

Materials

Though the kit comes with instructions, here’s a few helpful tips:

  1. Remove rust spot with 80 grit sandpaper (included), angle grinder, metal brush, or even a hammer. Sand away all paint 25mm surrounding the area for repairing the rust. Otherwise the fiberglass won’t stick properly.
  2. (Optional) If it’s not possible to remove all of the rust, use a rust converter to prevent the rust from spreading. I like the 3M brand. Either way follow to package instructions before moving on. Use a Q-tip to dab the converter on small spots.
  3. Measure out aluminum mesh before going further. It has to go an extra 25mm around the hole. 
  4. Both the fiberglass mixture and the body filler have to be applied within four minutes of starting to mix. This is really quick and they both begin to stiffen by the end. For this, it’s best to mix them close by the vehicle.
  5. Apply the fiberglass solution before and after putting down the aluminum mesh. It’s important to cover the entire area surrounding the mesh. This insures the mesh is ‘welded’ into the body and covers the hole for good.
  6. For the body filler mixture, I ended up just using my gloved fingers to smooth it down because at this point the plastic card was all bumpy from the other solutions. The first time there were a lot of air bubbles when I tried to smooth it down and it wasn’t the smoothest sanding down. Under the time limit, it’s hard to get a perfect finish the first time.
  7. After sanding down the body filler before spraying primer (included) if the end product isn’t smooth enough apply more body filler to fill in the holes and try again. Otherwise it’s good to go. Just remember the primer and paint will help smooth out and tiny details, so it should look better once they’re applied.

Working on a van build? After repairing rust it’s time to move onto insulation, check out how I insulated my van.

@gabtravelling