The Best and Safest Way to Cut Carbon Fiber Sheets
So you determined the best way to accomplish your carbon fiber project is to purchase carbon fiber sheets and cut them yourself. This is certainly a valid option, but there are a few things to know before you begin, to ensure the safest and highest quality cutting job.
There are a few risks inherent in cutting carbon fiber sheets. These include:
- Irritation to skin, eyes, or lungs from fine resin dust particles
- Sharp edges along the cut line
- General risks involved with using high-speed cutting tools
- Minor risk to equipment due to the electrical conductivity of carbon fiber dust
To minimize these risks, follow a few best practices:
- Work in a well-ventilated environment.
- Use extraction equipment to remove the dust as it is produced. This could be as simple as a shop vac, or you could invest in equipment such as a downdraft table.
- Always wear respiratory protection. Carbon fiber dust isn’t toxic, but the fine dust created by cutting carbon fiber sheets can be an irritant to your lungs.Therefore, it is always best to wear a respirator. Use a dust mask rated as P1 (for occasional use), P2 (to filter finer particles), or even P3 (for the best protection). If you will be cutting carbon fiber sheets extensively, consider investing in a reusable respirator.
- Protect your skin. Thin edges of carbon fiber sheets can become very sharp when cut, so exercise caution. Additionally, your hands, especially between your fingers, can become quite irritated from fine dust particles. Wearing thin surgical gloves can offer protection. If dust does get on your skin, wash it off using water.
- Wear eye protection. Any time you are working with power tools, wearing safety glasses or goggles is recommended.
When selecting tools to cut carbon fiber sheets, consider that the cutting surface of the tool should be as fine as possible. Course cutting surfaces can splinter, fracture, or chip the carbon fiber sheet. The best blades for this purpose will have a fine grit on the cutting edge rather than teeth. If you do opt for a tool with cutting teeth rather than an abrasive edge, the teeth should be as fine as possible, such as tools designed for metalworking rather woodcutting. Be aware that cutting carbon fiber sheets will create more wear and tear on your cutting blades than other projects.
When preparing to cut your carbon fiber sheets, always mark your cut first, and then cut slightly wide of that mark. This allows room to sand the carbon fiber sheet back slightly to remove any chips or splinters that might occur, ensuring a smooth, accurate edge.
Use a cutting surface such as wood or high-density foam block to rest your carbon fiber sheet on, allowing the cut piece to fall to the worksurface below.
Cutting Carbon Fiber Sheets
There are a variety of basic tools that work well for cutting carbon fiber sheets. Here are a few options:
- Hacksaw: A metal hacksaw fitted with a fine-grit blade works well for straight cuts on prepreg carbon fiber sheets.
- Dremel tool: For more complicated shapes, a Dremel or similar rotary tool fitted with a tungsten carbide wheel is a great option.
- Drill: If you need to cut a piece from the interior of a carbon fiber sheet, use an electric drill fitted with a metalworking bit to create a pilot hole.
- Rod saw: Once you drill the pilot hole, use a rod saw with an appropriate blade to make the cut. Open the rod saw, thread the blade through the pilot hole, then screw the saw back together and make your cuts.
- Angle grinder: An angle grinder will cut a bigger job very quickly. This option is best for cutting straight lines very quickly and smoothly. Because it goes so fast, it is easier to make a mistake, though, so exercise caution.
- Jigsaw: A jigsaw fitted with a tungsten carbide blade is a great tool for making curved, profiled, or intricate cuts.
There are a few steps you can take after you’ve finished cutting your carbon fiber sheets to give the cut edges your product a final polish:
- Purchase or make a sanding block to sand the edges. Start with coarse sandpaper to smooth rough edges and chips, and then move to 200-grit sandpaper to smooth the edges. You can even finish up with a 240- or even 400-grit sandpaper to polish the edges to a gloss.
- To get inside detailed areas or corners, use a square, flat, or round metalworking file, depending on the area you’re trying to reach.
- To really smooth the insides of cut corners of your carbon fiber sheet, try rolling up 120-grit wet/dry sandpaper. As with the sanding block, you can then move to finer-grit sandpaper for a smooth polished finish.
In most cases, sanding or filing is all you need to do to create a beautiful edge on your cut carbon fiber sheet. However, if your product will be exposed to a harsher environment, such as a marine environment, you can mix a two-part epoxy laminating resin to seal the edges. Look for wording such as “epoxy coating resin” on the product label. Such a coating will cure with a clean, hard finish that can then be wiped with a lint-free cloth to give a glossy, smooth, sealed edge to your cut carbon fiber sheet.