How to Improve the Surface Quality of Fatcarbon® Carbon Fiber Parts with Wet Sanding

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Posted by ovidijus on 3.23.23 in Workshop

Carbon fiber is a popular material used in many industries because of its lightweight, high strength, and durability. However, machining carbon fiber can be a challenging task (more about machining in our next blog post), as it can cause tool marks and other surface defects that can affect its appearance and performance. Fortunately, wet sanding is an effective method to remove tool marks and improve the surface quality of fatcarbon® carbon fiber parts.

A few supplies that you will need…

supplies for carbon fiber sanding

To start wet sanding, you will need a few supplies:

  • Gloves: Used to protect hands from carbon fiber debris and ensure safety while handling the parts.
  • MaskTo protect your lungs.
  • Sandpaper of different grits: Used to remove tool marks and improve the surface quality of carbon fiber parts. Ranging from P320 to P1200 or higher grits.
  • Flat surface: Used to place the sandpaper on, such as a glass or granite table. This provides a stable and even surface to work on.
  • Sanding pad: Optional but useful to hold the sandpaper and apply gentle pressure to the carbon fiber part. It helps distribute the pressure evenly and prevent uneven sanding on rounded or small surfaces.
  • Soapy water: Used to help remove debris and prolong the lifespan of the sandpaper. It also helps keep the workspace clean and prevent dust from settling on the part.

Prepare your workspace…

And one more thing before you start sanding, it is essential to prepare your workspace. Ensure that it is clean and empty and that there is adequate lighting. Place the P320 sandpaper on the flat surface, and attach it with a small strip of tape. Pour some soapy water on the surface to help remove debris and prolong the lifespan of the sandpaper. Wear gloves to protect them from carbon fiber debris.

Assembled workspace for carbon fiber sanding in wet


The sample that we will use.

In this example, we will use a knife scale machined out of fatcarbon® forged carbon fiber “Dark matter” gold billet.

So let’s get started!

Place the carbon fiber part on the wet sandpaper P320 surface and apply gentle pressure. Move the part in short strokes in a circular motion until all tool marks are removed. Once you have removed all the tool marks, change the sandpaper to a higher grit, such as P600, and repeat the process for a few circular motions until the previous grit sanding marks are gone. You will quickly notice that even after a few strokes, the part surface looks flatter, move vividly, and has more visual appearance than before.

For surfaces with a small surface area, place them on the sandpaper, apply gentle pressure, and use linear motion back and forward to remove tool marks and imperfections.

fatcarbon sanding edge

By continuing the process with higher grits, such as P800, P1000, P1200, and so on, You can achieve the surface of the part rich in colors and a 3-dimensional shimmering look.
It’s important to note that before changing the grits of sandpaper, clean a part with clean water.

After achieving the desired surface quality, the next step is to decide how to protect and enhance the appearance of the carbon fiber part. Options such as polishing, clear coating, or applying wax can all serve to protect the surface and enhance its visual appeal. Each of these methods deserves its own separate blog post, but it’s worth briefly mentioning their benefits here.

And extra steps often lead to greater rewards.


Once you have achieved the desired surface quality of your carbon fiber part, the next step is to protect and enhance its appearance. There are several options available, including polishing, clear coating, or applying wax.
Clear coating the part with 1k or 2K clear coats can achieve a matte or glossy finish and give the part a deep, 3-dimensional look. However, a clear coating can be time-consuming and requires experience to do it correctly. But the results speak for themselves.

Another option is to apply wax or oil-based coatings, such as bee wax. This method is cost-effective and popular among carbon fiber enthusiasts. Simply rub a clean cloth into the wax and apply it in a circular motion to the surface of your part, then polish it with a clean towel. This method not only protects the carbon fiber surface from moisture, salts, and UV but also gives it a unique look.

Finally, for polishing, you can use hand or machine polishing, depending on the part’s size. A regular polishing compound works well on fatcarbon®, and you can try different grit compounds to achieve various gloss levels. The benefit of polishing is that you can achieve a high-gloss surface without a clear coating.

It’s worth noting that wet sanding can be time-consuming, but it’s a process that pays off in the end. By taking your time and being patient, you can achieve a flawless finish that’s both visually appealing and long-lasting. Additionally, wet sanding is not only useful for removing tool marks and surface defects, but it can also help to restore aged carbon fiber parts. So, if you have a carbon fiber component that’s looking a bit worn out, wet sanding might be the perfect solution to bring it back to life.

As always, if you have any questions or notes, don’t hesitate to contact us.