While some antiques may look a little worse for wear, sanding them can decrease their value further. In fact, sanding can be one of the most damaging steps of the refinishing process. What could seem like a minor issue, such as not covering a certain area or sanding against the grain, could cause many problems in later steps. So before you start renovating an older piece of furniture, make sure the task is worth undertaking. However, if you feel you must sand an antique furnishing, there are some careful ways to go about it.
Choosing the Right Sandpaper
When sanding down wood furniture you should always use aluminium oxide-based sandpaper as it lasts longer and works faster than other forms. You must always select your grit according to the result you want to achieve. A grit of 50 to 80 is rough and used for removing finishes, 100 to 140 is medium and used for sanding rough woods, 150 to 180 is fine and used for soft woods and secondary sanding, and 220 to 280 is very fine and used for touching up.
Sanding Flat Surfaces
For the first layer of sanding, you should use 120-grit sandpaper. Wrap it around a block of wood that's roughly the size of your hand. Place the sandpaper firmly on the flat surface, ensuring that your fingers aren't touching the furnishing. Place a small amount of pressure on the sandpaper block and wipe the surface, moving with the grain. Failure to move with the grain could cause damage to the piece's surface -- these blemishes will be highlighted when stain is applied. When you've finished sanding the whole surface, swap the 120-grit sandpaper for 220-grit sandpaper and repeat the process. When your sanding is complete, your furnishing's flat surface should have uniform smoothness.
Sanding Oddly Shaped Surfaces
A common problem when sanding antique furniture is dealing with odd surfaces. Victorian-style pieces often contain carvings of lion heads or spiral designs on chair and table legs. Sanding these areas with the wrong sandpaper can cause a significant amount of damage. To proceed with care, wrap 100-grit sandpaper around the oddly shaped area with your hand. In a linear motion, rub up and down with very light pressure. Remember to sand with the grain and work on small areas at a time.
Cleaning off Dust
When you have finished sanding the surface, you must thoroughly clean it. Use a dry, non-abrasive cloth, such as a tack cloth. Wipe the entire piece of furniture. Stop regularly and shake the tack cloth to remove excess dust, otherwise you could end up wiping the dust over the surface. Even the smallest speck of dust could prevent the stain or primer from properly binding to the surface, so be just as conscientious with this task as you were with sanding.