VARTM for Fiberglass Repair, Denver Colorado
This 30-something-year-old fiberglass hood needed some repairs. It suffered from corrosion and delamination especially at the edges at hinge mounts. Here is a look into our modern approach at fiberglass repair. We use a technique you might see when making a carbon fiber product but apply it to this fiberglass hood repair. The application is called Vacuum Assisted Resin Transfer Molding (or VARTM). The bag is used to seal our product from the environment and the resin is injected via vacuum created in the bag
We start by removing as much corrosion from the hood as possible so we can have a strong bond between the original material and the new fiberglass mat.
After the hood has been cleaned, we bring it to our infusion room. We lay three different materials on top of the hood before resin can be applied to it. First, we apply to sheets of chop strand fiberglass mat. The chop strand fiberglass is like oriented strand board you’d see in carpentry. The chop strand mat results in a smoother finished product that wont show through primer and paint. Next, we apply sheets of peel ply and this material acts as a release layer for the 3rd material. Finally, we apply our flow mesh. The flow mesh allows air to escape while the bag is under vacuum ensuring a strong bond of new fiber material to the original hood.
We pulled Sean off a project to assist with this hood so excuse the outfit change – the mask and suit aren’t necessary for this portion of the project.
Each fiberglass or carbon project has its own custom bag made for the VARTM process to begin. We attach our resin transfer tubes to the top layer of material and place the hood in the bag and seal it with High Tack – High Temp – Vacuum Bag Seal. We attach our resin transfer machine to our tubes and start the infusion process. The bag is vacuum-sealed and checked for leaks. After the bag passes a leak-down test we open a valve and inject resin into the bag.
When the resin has cured the repaired hood is removed from the bag and we peel off the peel ply and flow mesh to reveal the fiberglass surface. The hood then moves to its final prep stage of sanding and shaping to be test fitted to the vehicle and prepped for primer and paint.