If you have scratched plastic but wonder whether it can be useful, sanding it will give it a new lease of life. According to Hunker, sanding is the ideal way to restore hard plastic though there are a few considerations. As we enlighten you on how to sand plastic, you shall also learn the dangers involved and the measures to take for the best results.
How to Sand Plastic Using the Wet Sanding Technique
Sanding plastic gives it a smooth finish but if you are not careful, you can introduce new scratches to the surface. Therefore, you must always go light and never in the same direction. It Still Runs informs us that wet sanding is one of the ideal ways to acquire a smooth finish on plastic. However, if you sand in the same direction, you can scratch the material so much that it can be challenging to eliminate the new flaws; hence, using a circular motion is recommended. Still, it should not be one particular circle size because even then, the pattern will be embedded on the surface; different circle sizes of the circular motion are best. Wet sanding is the best method when you are going for an extremely smooth finish; therefore, it is mainly used on car body paints in readiness for a paint job. Sandpapers come in different grits, and when wet sanding, you should begin with lower grit sandpaper; about 200 grit is the best before changing to another with a higher grit for a smoother finish. It is referred to as wet sanding because a liquid, preferably water, is used as lubrication so that it washes away the grit particles left on the surface. Sometimes, detergent is added to the water to reduce water surface tension for better results.
Steps for Wet Sanding
The Tool Geeks lists all the steps involved in wet sanding plastic. The first thing you have to do is ensure the surface of the plastic is clean. So, remove any dirt, grime, or grease using a degreaser or mild detergent with some water. Alternatively, if the surface is too rough, a solution of vinegar and water in a 50:50 ratio will help to smoothen the surface even before you start sanding. Once your surface is clean, have another bucket of water and dip the sandpaper called silica carbide in the water. Leave it immersed for at least 10 minutes. Remove the sandpaper and begin wet sanding in irregular circular motions. Keep rewetting the sandpaper, and when working on a curved surface, you can attach the sandpaper to a foam pad. When done with sanding the surface, clean the residue and switch the sandpaper to one with a higher grit and repeat the process, beginning with wetting sandpaper and sanding in different circular strokes. Remember to use a light touch always. You can inspect the surface before switching the sandpaper again to ensure that the surface is smooth, using your fingers as a guide. Keep changing the sandpaper until you get the desired smooth finish, wiping debris and dust off the surface to help you notice any spots that require more attention. Once you get the preferred smooth finish, wash the surface and pat to dry. You can get the maximum shine by applying clear-coat polish on the plastic and buffing it.
Why Wet Sanding Plastic is Preferred to Dry Sanding
According to A Butterfly House, wet sanding and dry sanding are the same since both remove materials for a smoother finish. However, they are different because wet sanding requires using a lubricant, whereas dry sanding does not. Also, dry sanding does not result in as smooth a finish as wet sanding. Finally, wet sanding is done by hand, while dry sanding requires power tools. However, the main reason wet sanding is most recommended for plastics is that sanding generates heat due to the friction of the rubbing motion. Using water as with wet sanding helps mitigate heat generation, thereby preventing the melting of the plastic. Also, wet sanding prevents the dust formed during the sanding process from sticking to the sandpaper, which can clog the grit and cause the plastic to gall. Still, dry sanding is usually performed before wet sanding plastics, so it has a role to play in ensuring you acquire that smooth finish.
Dangers of Sanding Plastic
Yale School of Medicine published that sanding paint or filler material produces fine dust which is easily inhaled resulting in irritation of the eyes and breathing tubes. Such dust could contain loads of hazardous compounds that are harmful when ingested or inhaled. The higher the size of the grit, the finer the dust, and the best way to protect yourself is to wear protective gear. While large particles can be easily coughed up or settle in the nose, finer ones will likely go up to your lungs; hence, masking up is recommended. Some plastic is made up of resin, and resin dust has been known to cause severe respiratory issues. Inhaling it could result in headaches and permanent lung scarring; hence, it is advisable to ensure you are working in a well-ventilated area. Besides wearing dust masks, you can also have a fan blowing on you as you work, if you are maybe sanding in a basement without proper ventilation. Remember also that wet sanding is much safer than dry sanding because the water helps to keep the dust particles down. When dry sanding, you could also invest in a respirator to protect your lungs. Since the dust settles on everything in the room and sticks to it, it is best not to eat or drink while working because the foodstuff will have fine dust particles on them, and ingestion will be dangerous to your health.