When most car guys think of plastic body filler, the term “Bondo Buggy” comes to mind. We’ve all seen builds on the grass at car shows that have glossy paint but wiggle down the side. Lead remains the coolest and most legitimate filler in the eyes of many, but plastic filler is easier to work with and can be mastered relatively quickly, and has improved measurably over the years. Today plastic filler is used on the majority of modern collision work and the custom cars you see at local events.
Nevertheless, modern body filler applied poorly is as bad as the old-school stuff. We all know that a paint job is only as good as the underlying prep and it takes a fair amount of skill to finesse a car body to perfection before the final coats of color. Novices and driveway Di Vinci’s can get great results by massaging your project’s sheet metal to perfection and this video is a great 101 tutorial.
With no further ado, check out this video on YouTube from Speedway Motors. If you want a “how-to” on applying body filler, this 13-minute video is a step-by-step walkthrough that beginners and seasoned body men can benefit from. Joe McCollough of Speedway Motors took their project 1968 Chevy pickup to No Coast Customs and talked with bodyman Ben and they went through the steps properly. One of the key things the guys cover in the video is shoring up the combination of new and original sheet metal on a build. The C10 had an aftermarket tailgate and bed and there are helpful hints here to marry these disparate components into one seamless body.
Here’s a cheat sheet of the process
- To prepare a tailgate for paint with epoxy primer, first sand the epoxy with 220 grit sandpaper. This will reveal any low spots in the metal. Mark out the low spots and sand them lightly with 220 grit sandpaper and a red Scotch Brite. Then, clean the tailgate with wax and grease remover.
- Next, mix up some filler and apply it to the low spots, using a spreader to work it into the scratches. Let the filler dry for a few minutes, then sand it with 80-grit sandpaper. Use a razor blade to cut off any excess filler. Sand the filler again with 80 grit sandpaper until it is smooth and flush with the surrounding metal.
- Now it’s time to apply the primer. Apply a high-build primer to the filler and sand it with 80-grit sandpaper. Repeat this step until the filler is completely hidden and the surface is smooth.
Here are some additional tips:
- It’s better to spread the filler thin than to try to fill all the low spots in one pass.
- If you are filling a large area, use a straight edge to help you achieve a smooth finish.
- Sand the filler until it is completely smooth and flush with the surrounding metal.
- Apply the primer in thin coats and sand between coats to achieve a smooth finish.
- In this specific case, the tailgate is being prepped for a show car, so the gaps need to be dialed in perfectly. To achieve this, the filler is spread across both the tailgate and the bedside and then sanded together.
- This will ensure that the tailgate is completely flush with the bedside when it is closed.
- A stick with tape wrapped around it is used to set the gap size and clean out the excess filler. A straight edge is used to mark out where the filler needs to be applied to blend the tailgate into the bedside.