Bondo is a polyester putty designed for repairing damage caused by rust to automotive parts. However, applying Bondo is a complex process requiring certain skills and knowledge. Luckily for you, I’ve compiled a step-by-step guide that you can follow to eliminate rust from the wheel wells in your vehicle.
Follow these 10 steps to Bondo a rusted wheel well:
- Read instructions and safety precautions.
- Thoroughly clean the wheel well.
- Apply adhesive remover to the wheel well.
- Sand the rusted area.
- Use a paint stripper to remove paint and rust.
- Combine the Bondo filler with hardener.
- Apply Bondo to the affected area.
- Sand down the entire wheel well.
- Apply primers and disinfectant.
- Paint the wheel well.
Continue reading for a guide on applying Bondo to a rusted wheel well. I’ll give you a step-by-step guide to the entire process, and I will go over some pitfalls and common issues that people often encounter when trying to apply Bondo to a rusted wheel well.
1. Read Instructions and Safety Precautions
Before you can get started on your wheel well rust removal and repair, it’s worthwhile to acquaint yourself with the process and the risks involved. This allows you to avoid some mistakes that people make, and it also ensures that you don’t put yourself or your things at risk during the process.
Bondo is a messy material that forms permanent bonds with surfaces. Therefore, misusing Bondo could cause significant harm or discoloration to surfaces in your home. As a result, it’s worthwhile reading the entire instruction manual before getting started.
2. Thoroughly Clean the Wheel Well
Before applying the Bondo to your rusted wheel well, you’ll need to prepare the surfaces on your car. The first step in preparing your wheel well is to clean it thoroughly.
When cleaning the wheel well, you must ensure that you remove all dust and dirt from the surface. On top of this, you should use a disinfectant alcohol spray after cleaning to ensure that the surface is clean before you proceed.
3. Apply Adhesive Remover to the Wheel Well
Another step in preparing your wheel well for applying the Hindu is using adhesive removers on the surface. Adhesive remover breaks down and removes any layers of wax or protective coating that cover the paint job on your car. The protective coating will hamper the Bondo’s ability to bind to the car surface.
As a result, it’s imperative that you successfully remove all of the coatings or waxes from the wheel well. This allows you to apply Bondo evenly to get a fantastic finish at the end.
4. Sand the Rusted Area
After applying adhesive remover, it’s time to break out the sandpaper or sanding block. You will need to sand down the rusted areas on the wheel well until the rust is entirely gone. This process may take some time, and you’ll likely need to use different grits of sandpaper to get all of it.
When the Bondo is applied to your vehicle, it will form a raised area where the rust was previously. To prevent this, you will need to sand the affected area until there are small divots where the rust was previously. Doing so will prevent the dried Bondo from being raised above the rest of the panel.
Once you’ve sanded down the area, you’ll need to get started on removing the paint from the well well.
5. Use a Paint Stripper To Remove Paint and Rust
The purpose of using Bondo on your wheel well is to eliminate rust and improve the car’s visual aesthetics. However, the vehicle will not look right, and the repair will not be complete if there are patches of Bondo that are a different color from the car’s paint job. As a result, you will need to paint the wheel well after applying Bondo.
To achieve an even coat of paint on your wheel well, you must first remove the existing layer. Paint remover is the best product to use when removing paint. Apply paint remover generously to the tire wheel well, paying extra care not to get any on other panels on the vehicle, as it will cause the paint to fall off.
6. Combine the Bondo Filler With Hardener
The Bondo you purchase from a hardware store is not ready to fill the gaps in your car’s wheel well yet. Instead, you must prepare the mixture for it to work. There are two components (filler and hardener) to your Bondo mix that you’ll need to combine to get their job done.
The mix ratio for filler to hardener is 50:1. In other words, for every 50 parts of filler you include in the mix, you need a 1-part hardener. To visualize this, it’s about 7 or 8 drops of hardener to every golf ball-sized piece of filler.
Follow these steps to mix the Bondo filler and hardener:
- Place wax paper on your work surface.
- Pour a circle of filler of roughly 6″ (15.24 cm) across on the wax paper.
- Pour a thin line of hardener across the diameter of the circle.
- Mix the two together until thoroughly combined.
Mixing the Bondo on wax paper is an excellent way to reduce the mess and prevent the Bondo from sticking to or damaging your work surfaces. Remember not to use too much hardener in your mixture, as you can always add more if you don’t have enough.
When mixing the Bondo hardener and filler together, you mustn’t mix in a circular motion. Circular mixing allows air to permeate through the concoction, which can cause bubbles to form in the Bondo. Instead, mix it slowly but thoroughly to ensure that it is properly combined.
7. Apply Bondo to the Affected Area
At this point, you’ve sanded away the rust, stripped the paint from your wheel well, and mixed your Bondo. Now, it’s time to apply the mixture to the rust-damaged area. When applying the Bondo, ensure it fills in the divets you created earlier during the sanding step.
Don’t worry if the Bondo is raised above the rest of the wheel well after being applied; I will tell you how to fix this issue later in the process.
Once applied, the Bondo will start to harden. This process takes anywhere from 10 to 30 minutes. Once the Bondo has set and it’s hard to the touch, you can move on to the next stage.
8. Sand Down the Entire Wheel Well
After the Bondo dries out, you’ll need an 80-grit piece of sandpaper to smooth the surface. The Bondo will likely be slightly raised above the rest of the wheel well, clearly highlighting where the rust was before. This is not aesthetically pleasing, and it needs to be addressed.
Using the sandpaper, sand down the entire wheel well, including the Bondo, until the surfaces are flat and even. Once this step is done, your wheel well will show no signs of rust, but it will have discoloration from the exposed metal and the dried Bondo.
9. Apply Primers
To restore the aesthetics to your wheel well and to hide the evidence of your Bondo usage, you’ll need to apply a fresh coat of paint to the wheel. However, before you apply paint to a surface, you need to use some primers to ensure you get the result that you’re chasing.
To prepare the wheel well for painting, apply a coating of primer. This allows the paint to form a bond to the exposed metal on the wheel well and the Bondo. After applying the primer, wait for it to dry before you start painting.
10. Paint the Wheel Well
For best results, find a paint that matches the paint job on the rest of the vehicle. Once you’ve got your paint, you’ll need to cover the adjacent panels to the wheel well with paper and masking tape. This prevents the paint from covering other panels on your car.
Once you’ve isolated the wheel well for painting, it’s time to spray. Apply a generous and even coat of paint across the wheel well, including the areas you applied Bondo to. You may need to apply a second layer of paint after it dries to ensure that you get a high-quality finish.
Once you’ve finished painting, you should not be able to see where the Bondo was applied, and the wheel well will look good as new.
If you don’t feel confident painting your car after applying Bondo, you can take it to a professional to paint over the wheel well. This ensures that you get excellent results, but it will likely cost you a lot more money than painting the vehicle yourself.
Rust is like cancer in a car. It causes rot and ruins the aesthetics. If left untreated, it will spread and destroy the vehicle. As a result, you’ll need to restore the rust-damaged areas using Bondo. Bondo fills in the gaps left by rust; once painted over, you’ll never know the rust was ever there.
Remember these points when applying Bondo:
- Remove the paint, contaminants, and rust from the wheel well.
- Combine your Bondo mix and apply it to the rusted areas.
- Wait for Bondo to dry, and use sandpaper to smooth the service.
- Apply primers, then paint.