For DIY automotive painters and professionals alike, are an occassional hurdle on the road to a flawless finish. Even if you lay down a flawless coat, other “nibs” like dirt, hair, and even insects often find their way onto a wet surface. However, with the right tools you can tackle all these imperfections with confidence.
Since these types of flaws are typically above the paint surface, the process requires leveling and blending. The process, generally known as “denibbing,” focuses on repairing only the affected area without ruining the whole panel. Denibbing can be performed between paint coats for best results. When spraying base/clear paints, denibbing should at least be performed between the last base coat and the first color coat. On single-stage finishes, denibbing is usually done after the final coat is applied.
Denibbing requires patience and precision, especially when working on a car’s fresh paint job. If you’re unsure about using a tool or correcting specific imperfections, consider seeking guidance from a professional auto body technician or painter.
The Tools
A run razor, also known as a paint run remover or paint leveling razor, is an inexpensive and versatile option. It’s essentially a handle that holds a standard single-edge razor blade. An adjustable screw forces a slight bow profile onto he blade, allowing the edge of the blade to reach only the flaw.
This prevents scraping off the excess paint and damaging the surrounding area. However, it’s possible to gouge too deep if you dial in too much bend. Because of its slightly rounded cutting edge, the run razor is probably best suited to removing surface inclusions like dirt and insects.
Denibbing files are another popular option, particularly for paint runs. Small sections of flat, hardened metal files are mounted onto wooden blocks. These are often available in course or fine profiles depending on the severity of the flaw. They’re used to cut the nibs just to the point of level paint.
An alternative type of run tool is a denibbing block. It consists of a perfectly flat, mirror-smooth metal cutting blade with precise edges made of tungsten. It won’t dull like a single-edge razor blade and it can’t become loaded like a file can. Mounted to a small handheld block, the blade can also be removed for scraping the surface by hand.
Any of these processes will eventually require blending the edge of the flaw with primary paint finish. A succession of progressively finer-grit sandpaper on a flat sanding block is the preferred method, up to the point at which you would normally begin your color-sanding process. A set of precision run blocks will include several profiles for different contours. A small fingertip block that uses self-adhesive sanding sheets is ideal for blending nibs.
The Process
Allow the paint to dry – If the paint is still wet, do not touch it. Attempting to correct the run while the paint is wet can make the situation worse. Allow the paint to dry completely before proceeding.
Identify the flaw – Inspect the paint job carefully to identify areas with dirt, runs, or other imperfections that need to be corrected. These flaws may appear as small bumps or irregularities on the surface of the paint.
Prepare the surface – Before using any denibbing tool, ensure that the surface of the paint is clean and free from any loose debris.
Select the correct denibbing tool – Choose the appropriate tool based on the size and severity of the imperfections you need to correct.
Level the flaw – Use the denibbing tool to gently remove the surface flaws. Applying light pressure and use smooth, even strokes. Work in small sections at a time and avoid applying too much pressure, as this can damage the paint.
Check your progress frequently – Periodically inspect the corrected areas to assess your progress. Ensure that you’re not removing too much material and that the surface is becoming smoother and more uniform.
Feather the edges – After removing the major imperfections, use a fine-grit sandpaper or abrasive pad to feather the edges of the corrected areas into the surrounding paint. Blend the corrected areas to prevent noticeable lines or marks.
Cut and buff – Once you’re satisfied with the corrections, use a polishing compound and a clean microfiber cloth to polish the treated areas and restore shine to the paint.