wiseGEEK: What is Liquid Sandpaper?
Liquid sandpaper is a chemical solution that removes the thin top layers of the surface of a glossy painted item. It roughens the surface, making it easier to be repainted without having to be sanded down. Otherwise, the next coat of paint may not stick to the slick surface. This product can be found in hardware, home improvement, or paint stores.
The truth is that the solution does not actually do any real sanding, and it only removes gloss from a painted surface. If the surface has bumps or imperfections that need to be smoothed, it won't do that. It doesn't work as paint prep for shiny metal or tile, either. Liquid sandpaper can also be found under the names "deglosser," "liquid deglosser," and "wet sanding ."
The main benefit of using deglosser is that it is quicker than traditional sanding and doesn't require the same physical strength. This is especially true if the particular surface has ornate designs or extensive detailing. Sanding can also be quite messy because it leaves dust behind that requires extra cleanup. Older paint products may even contain lead, releasing potential toxic dust if sanded the traditional way.
Before using liquid sandpaper, certain precautions should always be followed. Some of these chemicals have very strong
fumes, so wet sanding techniques should only be used in well-ventilated areas to avoid possible injury. The chemicals can be dangerous if it comes into contact with the skin, so gloves must always be worn. If it does come into contact with the skin, the affected area should be washed promptly with soap and water. Eye protection should also be worn; if the chemical gets into the eyes, they should be rinsed with water immediately and medical assistance sought.
The first step in using this product is cleaning the painted surface thoroughly with a mild soap and some water. The surface can then either be wiped dry with a clean lint free cloth or left out to air dry. A lint free cloth is necessary to avoid leaving pieces of dirt, grit, or cloth on the item being restored or repainted.
Once all the moisture is completely gone, another lint-free cloth can be used to rub in the liquid deglosser. It should then be allowed to sit for the time specified in the directions on the package. The final step is to dry the surface with another clean cloth, although some brands require the surface to be rinsed instead. People should always follow the directions on the product package.Source: m.wisegeek.org