Hey guys, if you're a proud owner of a 1999 Polaris Sport 400, you know these machines are absolute workhorses. But let's be real, after years of hitting the trails, those plastics can take a beating. Cracks, fading, scratches – it all adds up! But don't you worry, because bringing those plastics back to life is totally doable. This guide will walk you through everything you need to know about repairing and restoring the plastics on your 1999 Polaris Sport 400, from simple fixes to more involved restoration projects. So, grab your tools, and let's get started!

Understanding Your 1999 Polaris Sport 400 Plastics

Before we dive into the repairs, it's essential to understand the type of plastics used on your 1999 Polaris Sport 400. This knowledge is crucial for choosing the right repair methods and materials. Generally, these machines utilized a blend of plastics designed for durability and flexibility to withstand the rigors of off-road riding. These plastics are often a mix of Polyethylene (PE) or Polypropylene (PP), which are known for their impact resistance and ability to flex without cracking easily. Identifying the exact type of plastic might be tricky without specific markings, but understanding these common types will guide you in your repair choices. Knowing the plastic type helps determine which adhesives, fillers, and paints will work best. For instance, some plastics may not bond well with certain adhesives, and using the wrong type could lead to the repair failing down the line. Additionally, the original color and finish of the plastics will influence your approach. Are they faded and sun-damaged? Or are there deep scratches and cracks that need addressing? These considerations will shape your repair strategy.

Now, let's talk about the common issues you might face. Cracks are, unfortunately, a frequent problem. They can happen from impacts, stress, or even just the aging of the plastic. Fading and discoloration are another biggie, especially if your ATV spends a lot of time in the sun. Scratches are practically unavoidable, right? From branches, rocks, and the general wear and tear of riding, they’re bound to happen. And finally, you might encounter broken mounting tabs, which can be super frustrating because they are critical for securing the plastic panels to the frame. By familiarizing yourself with these common problems, you'll be able to prepare accordingly. Knowing the issues helps you to create an effective strategy. It enables you to select the appropriate repair techniques and materials, ensuring that your efforts are both efficient and successful. This preparation means you'll be better equipped to tackle each problem head-on and make informed decisions about your repair process.

Tools and Materials You'll Need

Alright, before we get our hands dirty, let's gather up the necessary tools and materials. Having everything ready to go will make the repair process much smoother and less frustrating. You'll need some basic hand tools, like a screwdriver set (both Phillips and flathead), a socket set, and maybe a small ratchet. These will help you remove and reinstall the plastic panels. For cleaning, you'll want some degreaser or plastic-safe cleaner, along with some clean rags or microfiber cloths. Also, consider having some sandpaper on hand, with various grits, to smooth out surfaces before painting or applying any fillers. In terms of repair materials, you'll need to assess the extent of the damage. For cracks and breaks, plastic-specific adhesives or a plastic welder are ideal. Epoxy or super glue can work in a pinch for minor cracks. For filling in scratches or gouges, you might want plastic filler or body filler, which is designed to bond with plastic surfaces. And finally, if you're planning on repainting, you'll need primer and paint that's specifically made for plastics, along with clear coat to protect the finish. Make sure to choose colors that match your original plastics or opt for a custom look! Don't forget safety gear! Gloves, safety glasses, and a well-ventilated workspace are crucial. You want to protect yourself while working on your Polaris Sport 400.

Repairing Cracks and Breaks

Dealing with cracks and breaks in your 1999 Polaris Sport 400 plastics is a pretty common repair, and it's totally manageable with the right approach. Let's start with small cracks. For these, a plastic-specific adhesive will often do the trick. Clean the area thoroughly with degreaser and sand around the crack to create a better surface for the adhesive to grab onto. Apply the adhesive according to the manufacturer's instructions, and then clamp the pieces together, or use tape to hold them in place while the adhesive cures. Larger cracks and breaks might need a bit more muscle. A plastic welder is a great option here because it actually melts the plastic together, creating a strong, permanent bond. If you don't have a plastic welder, you can use a combination of adhesive and backing material, like fiberglass mesh, to reinforce the repair from the inside. This is particularly helpful for breaks in areas that experience a lot of stress.

First, prep the area by cleaning and sanding the broken edges. Then, apply the adhesive to the edges, and carefully align the pieces. Next, cut a piece of fiberglass mesh slightly larger than the break, and place it on the inside of the panel, covering the crack. Use more adhesive to secure the mesh to the plastic, ensuring it's fully bonded. Clamp the pieces together or use tape to hold everything in place until the adhesive cures completely. This technique provides a strong, durable repair that can withstand the vibrations and impacts of riding. When dealing with cracks and breaks, it's also worth checking the mounting points around the damaged area. Sometimes, a crack can be caused by stress from a loose or damaged mounting tab. If a mounting tab is broken or severely damaged, it will require repair or replacement. This might involve using epoxy to rebuild the tab or installing a new one. Before reassembling the plastics, make sure that the mounting points are secure, as this will help prevent future cracks and breaks.

Step-by-Step Guide to Crack Repair

1. Preparation: First things first, clean the area around the crack thoroughly with plastic-safe cleaner or degreaser. Get rid of any dirt, grease, or debris that could mess up the repair. Then, sand down the area around the crack. You're aiming for a slightly rough surface that the adhesive can grip onto. Use sandpaper with a medium grit, something like 180 or 220 grit, and lightly sand both sides of the crack, extending about an inch or so beyond the crack itself. This will create a better surface for the repair material to adhere to.
2. Adhesive Application: Select a plastic-specific adhesive. There are several brands available, but make sure it is designed for the type of plastic on your 1999 Polaris Sport 400. Follow the manufacturer's instructions for mixing and applying the adhesive. Usually, you'll apply the adhesive to the crack itself, and then clamp the pieces together. Use clamps or tape to hold the parts firmly in place while the adhesive cures. This ensures that the crack is sealed tightly and that the pieces align correctly. Ensure you do not use too much adhesive, as excess can create unsightly bulges.
3. Reinforcement (if needed): For larger cracks or breaks, consider using a reinforcing material, such as fiberglass mesh or a plastic repair patch. After applying the adhesive, place the reinforcing material on the backside of the crack. This will provide added strength and durability. Use more adhesive to secure the reinforcement, ensuring that it is fully bonded to the plastic. After the adhesive has cured, your repair should be durable and ready for action. Be patient and give the adhesive plenty of time to fully cure before reassembling the plastics. The curing time will depend on the type of adhesive you use, so always refer to the manufacturer's instructions.

Fixing Faded and Scratched Plastics

Faded and scratched plastics can make your 1999 Polaris Sport 400 look a bit rough around the edges, but don't worry, there's a lot you can do to bring back the shine! For fading, the best approach is often to repaint the plastics. But first, you'll need to prep the surface by cleaning and sanding. Use a plastic-safe cleaner to get rid of any grime or old wax. Then, lightly sand the entire surface with fine-grit sandpaper (around 400 or 600 grit). This creates a good surface for the paint to adhere to. After sanding, give everything another good cleaning to remove any sanding dust. Apply a primer designed for plastics. Primer helps the paint stick and provides a uniform base. Follow the instructions on the primer can for application and drying times. Once the primer is dry, you can apply your paint. Use a paint specifically made for plastics, ideally in the original color or a color of your choice. Apply several thin coats of paint, allowing each coat to dry completely before applying the next one. This helps prevent runs and ensures a smooth, even finish. And finally, after the paint is fully dry, you can apply a clear coat to protect the paint and give it a glossy finish. The clear coat provides UV protection, which helps prevent future fading. For scratches, the approach depends on how deep they are. For shallow scratches, you might be able to buff them out using a polishing compound and a power buffer or a hand-polishing pad. This will help smooth out the surface and make the scratches less noticeable. For deeper scratches, you might need to use a plastic filler to fill in the scratch before repainting.

Step-by-Step Guide to Plastic Restoration

1. Cleaning and Preparation: Start by giving the plastics a thorough cleaning with plastic-safe cleaner or degreaser to remove dirt, grease, and old wax. This is crucial for ensuring that your repairs and paint adhere correctly. Then, rinse the plastics with water and let them dry completely. Next, sand the entire surface of the plastic panels. Use a fine-grit sandpaper (400-600 grit) to lightly sand the surface. This will remove any imperfections, create a good surface for the primer and paint to adhere to, and help to smooth out any scratches. Be sure to sand in a consistent direction and avoid applying too much pressure, which could damage the plastic.
2. Scratch Repair: If there are scratches, address them before painting. For shallow scratches, use a polishing compound and a buffer or a hand-polishing pad. Apply the compound according to the manufacturer's instructions and buff the area until the scratches disappear or become less noticeable. For deeper scratches, you will need to fill them in with plastic filler. Apply the filler according to the manufacturer's instructions and sand it smooth once it has dried. This step is crucial for achieving a smooth, even surface before applying primer and paint.
3. Priming and Painting: After sanding and scratch repair, clean the plastics again to remove any dust or debris. Then, apply a primer designed for plastics. Follow the manufacturer's instructions for application and drying times. This is an essential step as it promotes paint adhesion and helps create a uniform surface. Once the primer is dry, apply several thin coats of paint specifically designed for plastics, allowing each coat to dry completely before applying the next one. Thin coats will help prevent runs and ensure a smooth, even finish. If you're matching the original color, make sure to use a paint that closely resembles it. Finally, apply a clear coat to protect the paint and give it a glossy finish. This will provide UV protection and help the paint last longer.

Addressing Broken Mounting Tabs

Broken mounting tabs can be a real pain, as they prevent your 1999 Polaris Sport 400 plastics from attaching properly. The good news is, they're usually repairable! First, assess the damage. If the tab is broken off entirely, you'll need to rebuild it. Plastic-specific epoxy works great for this. Clean the area around where the tab was, and then mix the epoxy according to the manufacturer's instructions. Apply the epoxy to rebuild the tab, shaping it as close as possible to the original. You might need to use a small piece of plastic or cardboard as a form to shape the new tab while the epoxy cures. Once the epoxy has cured, you can drill a new hole for the mounting hardware. If the tab is cracked, but still attached, you can reinforce it with epoxy or plastic adhesive. Apply the adhesive to the crack and clamp it in place until it cures. You can also add a small piece of plastic or metal on the back for extra support.

Another option is to use a metal repair kit. These kits usually include small metal tabs and hardware to create a new mounting point. These are particularly useful if the original plastic is too damaged to be repaired with epoxy. Follow the instructions provided with the kit. This approach might involve drilling new holes or using adhesive to secure the metal tab. Before reassembling the plastics, always make sure that the mounting tabs are secure and properly aligned. This will prevent stress on the plastics and help prevent future damage. Also, consider adding washers or rubber grommets to the mounting hardware, as these can help distribute the load and prevent cracking around the mounting points. Properly addressing mounting tab issues is essential for ensuring that your plastic panels stay securely in place and continue to look their best.

Step-by-Step Guide to Fixing Mounting Tabs

1. Assessment and Cleaning: First, carefully examine the damaged mounting tab. Determine the extent of the damage. Is it completely broken off, cracked, or only partially damaged? Then, clean the area around the broken tab thoroughly with a plastic-safe cleaner or degreaser to remove any dirt or debris. If the tab is broken, you'll need to remove any remaining pieces of the tab from the plastic panel. Make sure the area around the broken tab is clean and free of any loose plastic pieces or debris. Prepare the plastic surface for the repair by sanding it lightly. A rough surface will help the adhesive or epoxy to bond properly.
2. Repair Options: If the mounting tab is completely broken off, use plastic-specific epoxy to rebuild the tab. Mix the epoxy according to the manufacturer's instructions. Apply the epoxy to the area where the tab was originally located, shaping it to resemble the original tab. You can use tape or a small piece of plastic as a mold to help shape the tab while the epoxy cures. If the mounting tab is cracked, but still partially attached, use plastic-specific adhesive or epoxy to reinforce the crack. Apply the adhesive or epoxy to the crack and clamp it in place until it cures. Reinforce the repair by adding a small piece of plastic or metal on the backside for additional support.
3. Reinforcement and Reassembly: Once the epoxy or adhesive has cured, drill a new hole for the mounting hardware. Ensure the new hole is properly aligned with the frame. If you've rebuilt the tab, make sure the new tab is strong and can properly support the panel. Inspect all remaining mounting tabs for any other cracks or weaknesses. Add washers or rubber grommets to the mounting hardware to distribute the load and prevent future cracking around the mounting points. Finally, reassemble the plastic panels. Ensure that all mounting tabs are securely attached and that the panels are properly aligned. Double-check all mounting hardware to ensure it is tight, but not over-tightened.

Prevention and Maintenance

Let's talk about keeping those 1999 Polaris Sport 400 plastics in tip-top shape. Prevention is always easier than repair, right? First, try to avoid unnecessary impacts. Be mindful of obstacles on the trail, like rocks, trees, and other hazards that could potentially damage your plastics. If you're riding in tight areas, slow down and take it easy. Routine cleaning is essential. After each ride, hose down your ATV to remove dirt, mud, and debris. Use a plastic-safe cleaner to remove any stubborn grime. Regular cleaning prevents the buildup of abrasive materials that can scratch your plastics over time. Consider applying a protectant. There are various plastic protectants available that can help to protect your plastics from UV damage and fading. These products can also add a layer of protection against scratches and impacts. Inspect your plastics regularly for any signs of damage. Check for cracks, scratches, or loose mounting hardware. Catching problems early can prevent them from becoming more serious. If you notice any issues, address them promptly. Regularly tighten all mounting hardware. Vibration from riding can cause the hardware to loosen over time, which can lead to stress on the plastics and cause damage. By implementing these preventive measures, you can extend the life of your plastics and keep your 1999 Polaris Sport 400 looking its best. The right maintenance keeps your ride sharp!

Conclusion: Keeping Your Polaris Sport 400 Looking Great

So there you have it, folks! Repairing the plastics on your 1999 Polaris Sport 400 might seem like a daunting task, but with a little know-how and some elbow grease, you can definitely bring those panels back to life. From simple crack repairs to complete restoration projects, this guide has given you the tools and the knowledge to keep your ATV looking its best. Remember to always use the right tools and materials, and don't be afraid to take your time. Proper prep work is key to a successful repair, so make sure to clean and sand the surfaces thoroughly before applying any adhesives, fillers, or paints. And always prioritize safety. Wear gloves, safety glasses, and work in a well-ventilated area. Your 1999 Polaris Sport 400 is a great machine, and keeping it in good condition means you can enjoy many more years of off-road adventures. So get out there, tackle those repairs, and enjoy the ride! Happy trails, and keep your Polaris looking sharp!