Maple lumber can display convoluted grain patterns and differences in texture as well as a smooth, almost featureless grain. The resulting variety in porosity can cause problems when you stain the wood. Some species of maple are soft, but hard maple is one of the hardest domestic hardwoods, and can be difficult to work with. A few tips can help you overcome these problems while refinishing maple woodwork or furniture so you can produce evenly toned and strikingly beautiful finished work.
Stripping the Old Finish
Most refinishing jobs begin with removal of the existing finish. Because it's hard and has a relatively closed grain, maple can be easier to strip than other types of wood. Don't think you can do it just by sanding, though. Your sander may lift the bulk of the finish, but a significant amount remains in the grain and is likely to show up when you restain. Use a methylene chloride-based stripper or -- if you want to avoid breathing those fumes and have extra time -- a soya-based one. After stripping, neutralize the residue by wiping it with a damp rag. Then let the wood dry before proceeding.
Stripping may be straightforward, but sanding maple can be difficult because of its hardness; you can seldom remove all the previous stain and residue without resorting to a sanding machine. Orbital sanders leave circular scratch marks that may not become visible until you apply stain or finish. You can avoid them by "running through the grits," which means to sand with progressively finer grits of sandpaper. Do a final hand-sanding with 150-grit paper. Clean the dust off with a rag, and then dampen the wood with a moist rag; look for any marks you missed and sand them out. That can make the difference between a so-so finish and a spectacular one.
Condition or Seal Before Staining
Maple is notorious for accepting stain unevenly -- the grain can be a mixture of straight, even fibers and curled ones that terminate in end grain, which stains darker than surface grain. One way to keep the color uniform is to apply wood conditioner with a paintbrush, but commercial conditioners often deposit only a thin paraffin film that allows some of the stain through. In light of this, some refinishers seal the grain with a thin coat of the finish they're going to use or with sanding sealer before staining. The procedure is simple: Apply the sealer, scuff with 320-grit sandpaper, and then stain in the same way you would if the wood were unsealed.
Toning the Finish Coat
Even when you seal the maple and apply a stain, the color may be more uneven than you'd prefer -- and there's an easy way to remedy that. Apply a coat of finish, and then tone the wood by spraying pigment on the dried finish or wiping on a gel stain. You can dissolve the pigment in a solvent, such as lacquer thinner, or in the finish you're using, but using a gel stain is the easiest option, requiring only a paintbrush and rag. Use this technique to darken edges for an antique effect, or darken the entire surface to even out color discrepancies from staining.