Every beautiful paint job starts with a thorough sanding.
The importance of a thorough sanding job prior to painting the body of a car warrants consideration. A poor sanding job can render a paint job a failure through immediate chips and cracks due to uneven or rough surfaces. Whether you're simply aiming to repaint a dent recently covered in filler or a complete paint job of the entire auto body, understanding what tools are necessary is a logical first step.
Rasp
A flat rasp is often the first tool used to even any areas where filler has been applied to cover dents or other imperfections. Not dissimilar to a cheese grater, a rasp with even a modest amount of pressure can tear through filler so care is need that the subsurface is not damaged. The ideal rasp will have a raised handle and will also be mounted to a frame. One hand grips the handle and the other rests on top of the frame so the hands are not in contact with the surface.
Sanding Board
Rough sanding begins with a sanding board or inline sander. A sanding board consists of a flat, rectangular-shaped material, often plastic, with a looping handle on the rear and a knob in front mounted to the top of the board. This hand tool ranges anywhere from three to four inches wide and 12 to 18 inches long. Sanding boards require the use of sandpaper that is manufactured with adhesive so it can be directly attached to the tool's underside.
Air-Powered Sanding Board
A compressed air-powered sanding board, also considered an inline sander, has a similar-shaped base to a manual sanding board. Much easier to use once proper technique is learned, this tool features an oscillating board that moves at very high speeds. One characteristic of air-powered sanding boards is that they are quite powerful. Users must maintain tight control of their work as this device can quickly sand through existing layers. Sandpaper is applied in the same manner as with manual sanding boards and this tool is also used specifically for rough sanding.
Foam Cylinder
Sanding the body of a car means sooner or later you will encounter curved areas. A dense foam cylinder is the tool of choice in these instances. A length of sandpaper is mounted to the foam with adhesive on its underside and simply wrapped around the foam cylinder.
Foam Blocks
Dense rectangular foam blocks of varying lengths are used for applying finer grits of sandpaper or when wet sanding as they do not absorb water. Wet sending is generally the method of choice when using grits of 400 or finer.
Dual Action Sanders
A dual action (DA) sander is a type of electric random orbit sander. These sanders receive their name from the head and disk rotation of the tool during use. Dual action sanders utilize a round disk of sandpaper that adheres to the underside of the tool. Held in position via a molded handle directly over the disk, DAs are used in preparation for additional coats of paint.
