Omar Khalid
Plastic fenders on ATVs, motorcycles, and automobiles can suffer various types of damage, especially from collisions. Depending on the type of plastic, different repair procedures and products should be used. For instance, if the plastic is ABS, you can use acetone to dissolve it and perfectly bond the plastic back together. If the fender is made of fiberglass, you can work a small rod or metal mesh into the underside of the fender. You can also use a plastic welding kit, which uses a special hot air gun and plastic welding rod to repair the crack.
Characteristics and Values Table for Reattaching a Plastic Fender
| Characteristics | Values |
|---|---|
| Identify Plastic Type | SMC (sheet molded compound), Thermoset, ABS, polypropylene, or Fiberglass |
| Repair Method | Plastic Welding, Adhesives, Filler, Drilling, Sanding, Painting |
| Tools/Materials | Hot Air Gun, Plastic Welding Rod, Adhesive Filler, Drill, Sandpaper, Primer, Paint |
| Preparation | Clean and Dry Surface, Drill Small Holes Around Crack, Feather Back Paint |
| Adhesive Application | Pour Adhesive, Soak Fiberglass Mat, Secure with Tape, Let Dry |
| Sanding and Finishing | Use Fine Sandpaper, Sand Until Even with Surface, Paint to Match Color |
Explore related products
What You'll Learn
Identify the plastic type
It is important to identify the type of plastic used in your car's fender to ensure that you select the appropriate materials and repair procedures. There are several types of plastics used in the automotive industry, including Polyvinyl Chloride (PVC), Polypropylene, Polycarbonate, and Acrylonitrile Butadiene Styrene (ABS). Each type of plastic has unique properties and requires specific handling and maintenance.
One way to identify the plastic type is by looking for an identification code or number plate, which is usually located inside the plastic part. This code is typically enclosed by the symbols ">" and "<" and provides information about the composition of the part, including the type of material and any reinforcement. Additionally, you can find details such as the manufacturing date of the part by interpreting this code.
Another method to determine the plastic type is through a series of tests, such as the float test and the burn test. While these tests might not provide a definitive identification, they can help rule out certain types of plastics. For example, you can perform the float test by cutting a shaving of plastic from an unpainted and uncontaminated area of the fender and placing it in a container of water. If the shaving floats, it is likely a thermoplastic polyolefin, whereas if it sinks, it is likely a thermoset non-polyolefin.
You can also differentiate between thermoplastics and thermosets by lightly grinding the plastic. If it smears, it is a thermoplastic, whereas if it powders, it is a thermoset. Thermoplastics are semi-rigid plastics that will melt when heated and typically require an adhesion promoter during repairs. On the other hand, thermosets are flexible plastics that do not melt and do not require an adhesion promoter.
Additionally, you can refer to resources such as the Plastic Identification and Refinishing Systems chart or the Bumper ID Table to help identify the specific type of plastic used in your car's fender. These resources provide comprehensive information about different plastics and can guide you in selecting the appropriate repair methods and materials.
The Hidden Plastic Problem: Dryer Sheets Uncovered
You may want to see also
Explore related products
Prepare the surface
To prepare the surface of a plastic fender for reattachment, you must first identify the type of plastic. Different plastics have different repair procedures. For instance, if the fender is made of ABS, you can use acetone to bond the broken pieces together. Simply apply acetone to both sides of the crack with a Q-tip, press and hold the pieces together for a minute, and then sand and paint the surface.
If you are unsure of the plastic type, or if it is not ABS, you can try using a small amount of Bondo to see if it adheres to the plastic. Alternatively, you can use a two-part adhesive filler, which can be purchased from an auto-body supply shop. Before applying the adhesive, drill a small hole at the end of the crack and drill holes around the perimeter of the crack to prevent it from spreading. Then, use 80-grit sandpaper to feather back the paint and roughen the surface of the plastic.
Once the surface is adequately prepared, wipe it down with plastic cleaner or alcohol, and allow it to air dry. Cut a piece of fiberglass mat slightly larger than the crack, and soak it in the adhesive mixture. Place the mat over the crack on the underside of the fender and secure it with tape. Leave it to dry, then remove the tape, flip the fender over, and cover the fiberglass mat with a thick coat of repair plastic.
Use a putty knife to smooth out the repair plastic, ensuring that there are no air bubbles. Allow this layer to dry, then sand the surface with 60-grit sandpaper until it is even with the fender. Finish by sanding the surface with 400-grit sandpaper and painting it to match the colour of the fender.
Carolina Rigging Plastic Worms: The Ultimate Guide
You may want to see also
Explore related products
Use adhesive or filler
Before using adhesive or filler to reattach a plastic fender, it is important to identify the type of plastic. Different plastics have different repair procedures. For instance, if the plastic fender is made of ABS, acetone can be used to dissolve the plastic and repair the crack. Polyethylene, on the other hand, can be repaired with a hot air gun and a plastic welding rod. Fiberglass fenders can be repaired by working a metal mesh or small rod into the underside of the fender.
Once the type of plastic is identified, the crack can be repaired with adhesive or filler. First, drill holes around the perimeter of the crack. Then, use heavy 60-grit sandpaper to sand the inside and outside of the fender, sanding one inch past the patch area. Use a crosshatch sanding pattern, sanding at 90-degree angles. Wipe the fender with a plastic cleaner or alcohol, and let it air dry.
Next, cut a piece of fiberglass mat to cover the crack and overlap the drill holes by at least half an inch. Prepare the adhesive according to the instructions, and pour it into a cup. Soak the fiberglass mat in the adhesive and lay it flat over the crack, using blue masking tape to secure it tightly. Let it dry, then remove the tape. Cover the fiberglass mat with a thick coat of repair plastic, smoothing it down with a putty knife and leaving a thick buildup.
Let the repair plastic dry, then sand the surface with 60-grit sandpaper until you reach just above the fender height. Finish sanding with 400-grit sandpaper until it becomes even with the fender surface. Finally, paint the repaired area to match the colour of the fender.
Avoid Cross-Threading: Tips for Plastic Pipe Perfection
You may want to see also
Explore related products
Smooth and sand the surface
To smooth and sand the surface of a plastic fender, start by using heavy 60-grit sandpaper to sand the inside and outside of the fender. Sand about an inch past the outside of the patch area, using a crosshatch sanding pattern and sanding at 90-degree angles. The goal is to rough up the plastic surface with deep grooves.
Next, wipe the fender down with a plastic cleaner or alcohol, and let it air dry. Cut a piece of fiberglass mat that covers the crack and overlaps the drill holes by at least half an inch. Prepare the adhesive according to the instructions and pour it into a cup. Soak the fiberglass mat in the adhesive mixture and lay it flat over the crack on the underside of the fender. Use blue masking tape to secure the mat tightly against the fender, ensuring that you do not cover the fiberglass mat entirely with tape, only the outside edges. Let it dry.
Now, flip the fender over and remove the tape. Cover the fiberglass mat with a thick coat of repair plastic, smoothing it down with a putty knife and leaving a thick buildup area of extra plastic putty. Let it air dry, then turn the fender face up. Use a flat file or sanding block with 60-grit sandpaper to sand the surface until you reach just above the fender height. Finish sanding the surface with fine 400-grit sandpaper until it becomes even with the fender surface and contour. Finally, paint the fender to match its original colour, if necessary.
How to Glue Wood to Plastic: Does It Work?
You may want to see also
Explore related products
Paint the fender
Painting your fender can be a simple task, but it is important to prepare your workspace and materials properly. Firstly, ensure your workspace is well-ventilated as paint fumes can be harmful to your health. Consider wearing a painter's filtered mask to protect yourself. You will also want to work in a space that is not dusty, such as a garage or shed, to prevent particles from settling on the fender as it dries.
Before painting, it is recommended to sand the fender lightly to create a surface that the paint can better adhere to. Use 1000 grit sandpaper and sand with soapy water, or use a red or green Scotch-Brite pad. Wet-sand the fender with 1000 or higher grit sandpaper until the sheen is gone from the areas you intend to paint. If you are painting over an old coat of paint, you may need to sand more thoroughly to remove the old paint and create an even surface.
Once you have finished sanding, wipe down the fender with a plastic cleaner or alcohol and let it air dry. You can then apply a primer. Primers designed for use on plastic are available, and it is recommended to use a white or black primer for the best colour outcome. Spray a light coat of primer and sand it lightly until it is flat, then spray on the colour.
You will need a nozzle that sprays in an I pattern, rather than the normal O pattern. Overlap each spray by 50% and apply 3-4 coats for the best results. It should take about a week for the paint to fully cure, but it should be usable the day after painting.
Plastic Number 1: BPA-Free or Not?
You may want to see also
Frequently asked questions
The process of reattaching a plastic fender will depend on the type of plastic it is made of. It is recommended to take the part to an auto body supply shop to identify the plastic. Once identified, you can use a two-part adhesive filler, drilling small holes around the crack and filling it in with repair material.
To repair a crack in a plastic fender, you will need to sand the area with heavy grit sandpaper, both inside and outside the fender. Then, cut a piece of fiberglass mat to cover the crack and soak it in adhesive. Secure it with tape and let it dry. Once dry, remove the tape, flip the fender, and cover the mat with repair plastic.
Plastic welding involves using a special hot air gun and a plastic "welding rod" to repair cracks in plastic. You can also use a soldering gun or a lighter to melt zip ties and weld plastic.
If the fender is made of ABS plastic, acetone can be used to dissolve the plastic and bond the crack. Alternatively, you can use superglue and baking soda, or a two-part epoxy putty to fill in the crack.
