There is good reason to be reluctant to sand a veneered surface during a refinish, because the danger of wearing through it’s real, and once you’ve completed that, it’s difficult to make repairs. That having been said, most veneers can maintain a moderate quantity of sanding, however there are ways to prevent it. Use a strong chemical stripper so you don’t have to sand off finish and bleach the wood to lighten it and eliminate spots.
Stripping
Most commercial chemical strippers will eliminate all of the end from furniture if you use them correctly. Distribute the stripper generously and give it time to work before scratching off it, but do not let it dry out, or you are going to have to disperse more. The finish generally indicates its willingness for scratching by forming bubbles. Have two types of scrapers available: a normal paint scraper and a pull scraper. Use the paint scraper for wide, flat areas and the pull scraper to get in corners and trim edges. Don’t let the corners of either scraper dig in the veneer.
Washing Away Residue
Removing the residue left on the wood after stripping is complete is important if you would like to prevent sanding. Many strippers are water soluble, but washing water increases the grain of the wood and may loosen the glue holding down the veneer. A better option is to wash the wood thoroughly with lacquer thinner. It’s more poisonous and volatile, however you can spread it openly without fear of undesirable side effects, and it may dissolve some of the blot. Rub it into horizontal surfaces with a cloth and use a cotton swab to get in the corners.
Bleaching
Once the wood is clean and dry, lighten the color with wood bleach. The best type to use is dependent upon the blot. A two-part way of sodium hydroxide and hydrogen peroxide works nicely for pigmented stains, while a strong chlorine bleach is more preferable for dyes. Oxalic acid, a third type of wood bleach, is best for removing water spots and blackened areas brought on by discoloration of tannic acid in the wood. It’s best to be careful so that you do not over-bleach. Chlorine bleach is the best option if removing stain is your main concern. It will not impact the natural colour of the wood.
Sanding
You won’t be able to avoid a little bit of sanding, however nicely the compounds work, because they’ll raise the grain somewhat and there are still very likely to be regions of irregular color. Stick to sandpaper grits nicer than 120 and sand by hand as far as you can. A detail sander is useful in corners and tight areas, but be careful to move fast. Always sand in straight lines, moving with the grain of the wood, and pay particular attention to edges, where the veneer is especially vulnerable to wearing through. It’s generally safe to sand large, flat areas with a hand sander, but raise the shredder and also assess your progress often.