How to Fix Paint Runs on Your Car

Paint runs, or sags, are a common imperfection in automotive painting, especially for those learning the craft. They occur when too much paint is applied in one area, causing it to drip or “run” before it dries. Fortunately, runs are almost always fixable, and addressing them properly can save your paint job. Experienced painters have developed several techniques to deal with this issue, both when the paint is still wet and after it has dried.

One effective method for dried runs is wet sanding. This involves carefully leveling the run using fine-grit sandpaper, lubricated with water to reduce friction and prevent scratching the surrounding paint. For very minor runs, a fine grit paper and a sanding block, even something as delicate as a rubber squeegee for precision, can be used to target just the run itself. The key is to be gentle and focused, removing the excess paint of the run without cutting into the surrounding clear coat more than necessary.

Another technique, often used by seasoned professionals, involves using a razor blade to carefully shave off the run. Holding the blade at an angle away from the sag allows you to slice off the excess paint, reducing the amount of wet sanding needed afterwards. This method requires a steady hand and a delicate touch to avoid damaging the surrounding paint.

For runs noticed while the paint is still wet, a quick trick involves using masking tape. A strip of masking tape can be lightly touched to the running paint, pulling the excess off. This needs to be done immediately as the run is forming and followed by additional wet coats to blend the area where the run was addressed. This technique is particularly useful for fresh paint and can minimize the need for sanding later on.

Ultimately, preventing runs in the first place is best practice. However, learning to fix them is a crucial skill in automotive painting. It’s often better for a beginner to apply enough paint to achieve a wet, glossy finish, even if it means dealing with a few runs, rather than applying too little paint and ending up with a dry, uneven surface that lacks shine. With practice and the right techniques, paint runs can be effectively repaired, leading to a professional-looking finish.