Those of you who have been following us for some time may be familiar with the ongoing build of our 3-piece carbon fiber front for the B13 chassis. While this has certainly been in process for MUCH longer than initially anticipated, we wanted to take a moment to educate our customers what exactly goes into producing high-quality carbon fiber components.
The process all begins with an overall idea of what the final product needs to accomplish. We knew, going into it, that we needed a front end that would be capable of concealing a 6" intercooler core, a front-mounted fuel cell, a 16v battery, and a 24.5x9.5 slick.
These are all common-place in the SFWD world so our goal was to bring that idea to fruition within the Nissan community.
The earliest stages are comprised of designing an exact replica of what the final product is to look like. This first stage needs to be dimensionally and cosmetically flawless, as this is what the final product is 100% based on. In the composites industry, this first stage is called a "plug".
This long, grueling process is by far the most time consuming and most costly of the entire build. For our front end this ended up being a significant monetary investment and an even more significant labor investment. As time went on, the process was refined (through much trial and error) until we were finally pleased with the 'rough-in' design. Every layer that was added needed to be further dialed in to achieve all aspects of our initial goal.
Beginning with an OEM front bumper and OEM fenders, we slowly built the plug into the rough size and shape that was desired.
Once the plug was dimensionally sound, it came time to remove it from the vehicle in 3 separate pieces so that we could further refine it cosmetically. With the amount of fillers used, this proved to be no easy task.
Certainly there were ways that we could have simplified this initial process, but hindsight is always 20/20. Every step of the way has been refined many times over; forever learning what works and what doesn't work.
After the plug was successfully removed from the vehicle, the hard work continued. Many many hours of block-sanding, filling, measuring, and more block sanding later; we began to see the final plug taking shape.
Patience always proves to be the most difficult in this build, but with that final goal in mind, our vision has always remained steady-focused.
After FINALLY achieving a perfectly symmetrical product, it was time to move onto primer. Using a specialized high-build primer in two separate stages, we were able to produce a plug that was ready for final sanding. The multiple stages provides a 'warning' barrier during final sanding so that we were sure to not break through the primer itself.
Once the primer had completely cured, we were able to move on to many more hours of sanding; working our way through multiple grits - eventually arriving at the buffing stage.
A high-gloss finish is paramount to a quality mold as ANY imperfections in the plug will most certainly make their way to the final product.
After the plug had been sanded and buffed to a high standard, it came time to prep it for the mold.
The mold is a 'negative' replica of the plug and is what will be used to produce the final carbon fiber component. Being that we use what's known as a 'resin infusion' process, the first step will be to add the necessary flanges to our plug. We will further dive into these later on.
With the flanges in place and all seams 100% sealed, we then apply multiple coats of 'release agent' and wax to the plug. There are many different preferences within the composites industry, but we find it most beneficial to utilize a semi-permanent release agent and wax over top of it. This gives us confidence that the parts will properly separate and the wax also provides a bit of 'bite' for the gel coat to adhere to.
With the release agents in place, it is now time to apply the gel coat. For molds, we use a heavy duty tooling gel coat that is capable of providing multiple parts out of a single mold.
This is applied liberally in multiple coats until the desired thickness is achieved.
With the gel coat set up, fiberglass is then set in motion. Beginning with a single, thin layer to reinforce the gel coat, the process is repeated many times over until the desired thickness is achieved. With such a large mold, it is absolutely paramount that it is rigid enough to not flex, warp, or crack under its own weight. This resulted in MANY gallons of resin used and an equal amount of fiberglass. The final mold is easily in the hundreds of pounds - no easy feat to move once it is complete!
After all the fiberglass has been applied and given time to fully cure, comes the moment of truth! Carefully and methodically, the mold is separated from the plug. What you're left with is an exact replica of all the man-hours that were previously invested. The edges of the mold can then be trimmed to the desired shape.
Every square inch is carefully examined for any flaws that may need to be addressed. Hairline cracks or other imperfections in the gel coat are repaired and then wet-sanded.
With everything up to par, it is ready for one last cut and polish before adding the release agent.
With the release agent applied and fully cured, the resin infusion process can finally begin!
A clear, UV-resistant gel coat is applied to the mold and allowed to set up. This gel coat will give a high quality surface finish that is able to be buffed as needed and has the added benefit of protecting your investment against the harmful UV rays at the track.
Many layers of carbon fiber fabric are then carefully laid in the mold in a very strategic fashion. It is a balancing act of weight and rigidity that we are after here. Adding reinforcement to the areas that are necessary will result in a product that is both strong and lightweight!
With the carbon fiber fabric carefully cut and placed into position, multiple layers of consumables are then added. These consumables are a necessary part of the resin infusion process. A peel-ply layer is first added to permit all of the additional consumables to be safely released from the cured product. Then a resin flow media is added that gives the epoxy resin a channel of which to flow through. Finally, the vacuum bag material is carefully placed on top and sealed to the flanges of the mold. This seal needs to be 100% air tight, and often times can result in multiple attempts and potentially wasted bagging material if not done properly. This air-tight seal is the MOST important part of a successful resin infusion.
With all materials in place, vacuum is applied to the bag and drawn down tight to the mold. After a thorough check for leaks, we can begin drawing epoxy resin into the carbon fiber fabric. The epoxy is weighed out mathematically based on the amount of fabric used before being mixed with a hardener. This assures that the proper resin/fabric ratio is achieved without wasting costly resin.
After hundreds, if not thousands of hours, later... the resin is slowly drawn through the carbon fiber fabric at a slow, controlled pace that assured the fabric is completely saturated without any voids. This entire infusion process is complete in less than an hour! The vacuum lines are then clamped off, and the vacuum pump is left to run overnight - assuring the mold stays completely compressed until the resin cures.
After a full 24hr cure, it is finally time to remove the carbon fiber from the mold! What you are left with is a high-quality, lightweight product that is ready for trimming. All excess flanges are carefully trimmed and sanded - one slip up might ruin an entire bumper! It is important to note that carbon fiber is extremely hazardous and the proper PPE should always be worn whenever cutting or sanding it.
After all the hard work invested, we are left with a front bumper that weighs in at just 6lbs, fully capable of housing all of your go-fast goodies!
Now that the bumper is done, it is time to repeat the entire process two more times... FENDERS!
The fenders are even more involved, as these molds will require multiple components in order to form all the necessary contours.
We are very excited be nearing the final stages of this long-awaited project. Hopefully this helps shed a small light on what exactly is entailed with producing a high-quality carbon fiber product.
So next time you're thinking, "Hey, somebody should build a carbon fiber...", maybe take a step back and understand exactly what it is that you're asking.
We hope you found this post informational, and thank you for supporting Vision One Racing!