Wooden Furniture Restoration Materials: Guidelines

Finishes, stains, fillers, and sealers vary from project to project and deteriorate over time. If you are doing a lot of refinishing work, you might want to maintain a small supply; otherwise, buy these materials as you need them for each project. There are, however, some basic refinishing and repair materials that you should have on hand, and both abrasives and adhesives should be stock items. In this article, we'll review the materials that should be on your must-have list for your workshop.

Paint and Varnish Remover

There are quite a few differences among removers. The less expensive removers usually contain some form of wax, may be toxic and flammable, and need to be removed with scrapers or abrasives. The more expensive ones are nonflammable and nontoxic, and some can be removed with water. There are also wipe-on, wipe-off removers and gel removers, many of which are noncaustic and easy to use. Experimentation will be your guide. The liquid is used on flat surfaces and the semi-paste on vertical surfaces, such as chair legs, where holding power is important.

Abrasives

Abrasives, the materials that work as tools, are essential in furniture refinishing and repair, but their primary role is not that of removing an old finish. Sandpaper, which used to play a major role in furniture stripping and preparation for finishing, has been replaced in part by a variety of chemicals and milder abrasives. Many professionals use sandpaper regularly, but some professional refinishers never use sandpaper, substituting steel wool and abrasive powders instead.

Sandpaper can theoretically be used for every step of refinishing, but you may prefer to use sandpaper for coarse work, steel wool for stripping and fine work, and pumice or rottenstone for finishes. The only way to decide is experimentation and experience.

Sandpaper

Sandpaper is made in a variety of types, both organic and inorganic. The organic types include flint paper and garnet paper, inexpensive papers that tend to wear down quickly. The inorganics, or synthetics, include aluminum oxide and silicon carbide papers, which cost more but last longer; they're available in much finer grits than are flint and garnet paper. Emery paper, used on glass or metal, should not be used on wood; use it only to clean furniture hardware.

Some professionals use only the synthetic papers (aluminum oxide and silicon carbide), while others believe the less expensive organic papers -- especially garnet paper -- are sufficient for all refinishing/repair needs. One thing is certain: flint paper, although the least expensive, wears down quickly and will cost you more in the long run. Use flint paper on gummy surfaces, where sandpaper becomes ineffective quickly. On other surfaces, the more expensive synthetic papers are faster-cutting and easier to use than the organics.

To see whether the synthetics are worth the money, start out with garnet paper and then do your next finishing job with a synthetic paper. If there's a big difference, you may feel the more expensive synthetics are worth the price; if not, you may go back to garnet paper. Use sandpaper of the type and grit appropriate for the job.

Steel wool and abrasive powders also are helpful materials to keep in your at-home workshop. Learn about their many uses in the next section.

Sandpaper Options For Your Project

Not sure which type of sandpaper to use on your furniture project? Check out the various types and their uses listed below.

Coarse Sandpaper

40 grit; 1 1/2 grit grade; flint, garnet, silicon carbide, emery papers available

50 grit; 1 grit grade; flint, garnet, silicon carbide, emery papers available

60 grilt; 1/2 grit grade; flint, garnet, aluminum oxide, silicon carbide, emery papers available

Uses: For initial rough sanding, smoothing rough surfaces, paint and varnish removal; some pros believe 40-grit is too rough for wood. Emery paper is used only for metal.

Medium Sandpaper

80 grit; 1/0 grit grade; flint, garnet, aluminum oxide, silicon carbide, emery papers available

100 grit; 2/0 grit grade; flint, garnet, aluminum oxide, silicon carbide, emery papers available

120 grit; 3/0 grit grade; flint, garnet, aluminum oxide, silicon carbide, emery papers available

Uses: For intermediate sanding, removing debris of rough sanding, prreparing wood for fine sanding. Emery paper is used only for metal.

Fine Sandpaper

150 grit; 4/0 grit grade; flint, garnet, aluminum oxide, silicon carbide, emery papers available

180 grit; 5/0 grit grade; flint, garnet, aluminum oxide, silicon carbide, emery papers available

Uses: For final sanding usually before application of stain/filler/finish. Emery paper is used only for metal.

Very Fine Sandpaper

220 grit; 6/0 grit grade; garnet; aluminum oxide, silicon carbide papers available

240 grit; 7/0 grit grade; aluminum oxide; silicon carbide papers available

280 grit; 8/0 grit grade; aluminum oxide, silicon carbide papers available

Uses: Some pros use very-fine-grit paper as the last step in wood preparation. Otherwise, used for light sanding between finish coats (between stain and varnish, for example).

Superfine Sandpaper

320 grit; 9/0 grit grade; aluminum oxide, silicon carbide papers available

360 grit; no grade description; silicon carbide papers available

400 grit; 10/0 grit grade; silicon carbide papers available.

Workshop Materials: Steel Wool, Abrasive Powders, Adhesives

Steel wool, abrasive powders, and adhesives are must-have materials for any at-home workshop, especially if you plan to work on furniture restoration or repair projects.

Steel Wool

Steel wool, in grades from medium to superfine, has assumed a major position in furniture work for smoothing and for removing finishes softened by paint remover. Steel wool is especially useful for veneers or delicate inlays, where the surface being refinished is very thin and could be damaged by sandpaper.

The one area where it can't compete with sandpaper is in smoothing down a rough surface. Steel wool does have its disadvantages: Some professionals feel that steel wool gums up too quickly and that it leaves too many steel particles behind. Use steel wool of the appropriate grade for the job. If you aren't sure what your options are or which one is best for the job, check out the Types of Steel Wool sidebar.

Abrasive Powders

For the very fine sandings of applied finishes, and for certain surface repairs, pumice and rottenstone powders are widely used. Pumice, available in grades F through FFF, is a bit coarser than rottenstone; both are useful for final finish smoothing and for stain removal. Start with rottenstone; if this is too mild, move on to pumice.

Pumice comes in F through FFF grades. It is a fine abrasive, used for rubbing between finish coats and for final buffing. It's also used for stain removal, when applied with oil (such as linseed oil).

Rottenstone does not come in a grade and is even finer than pumice. Rottenstone is used for buffing between coats, for final buffing, and for stain removal.

Adhesives

You'll probably use a variety of glues in furniture repair. Much of the choice comes down to personal preference, but a few basic differences should be kept in mind. The most important considerations are water-resistance and strength. If the furniture will be used outdoors or exposed to water, use a water-resistant or waterproof glue. If the part being repaired is structural, such as the leg of a chair, choose the glue for strength.

For most repairs, carpenters' glue is adequate-experiment to find the glue you like and get good results with. In special circumstances, use the appropriate glue for the job.

Adhesives Options

Below is a listing of the types of adhesives and when to use them for furniture refinishing projects.

Polyvinyl acetate glue (white glue)

White liquid, usually in squeeze bottle with applicator nozzle.

18 to 24 hour setting time

Clear dry appearance

Uses: General repair work. Don't use if exposed to moisture or water. Good for nonstructural wood-to-wood bonds.

Aliphatic resin glue (carpenters' glue, yellow glue)

Yellow liquid, usually in squeeze bottle with applicator nozzle.

12 to 18 hour setting time

Clear dry appearance

Uses: General nonstructural woodwork in dry environment; made especially for wood. Faster setting time, slightly stronger bond than polyvinyl acetate.

Plastic resin glue

Powder, mixed with water to creamy color. Sold in cans.

18 to 24 hour setting time

Clear dry appearance

Uses: Strong bond for structural supports. Needs a tight fit to set properly. Water-resistant, but not recommended for outdoors; can weaken under high temperatures and humidity.

Resorcinol glue

Two-part glue, liquid and powder. Sold in cans.

10 to 12 hour setting time

Brown dry appearance

Uses: Very strong, water-resistant. Use for both interior and exterior. Expensive. Once mixed, good for only three or four hours.

Hide glue

Liquid, orr flakes mixed with water and heated.

24 hour setting time

Amber, brown dry appearance

Uses: Traditional carpenters' glue. Liquid form easier to work with. Very strong bond. Avoid use in high humidty.

Contact cement

Light-colored liquid, sold in bottles or metal units.

Setting time on contact; cures in 1 to 2 days

Clear dry appearance

Uses: Best used for veneers. Donn't use for wood joints. Expensive and flammable.

Epoxy

Two parts, resin and hardener, mixed to thick liquid. Sold in tubes or cans.

5 minutes to 24 hour setting time.

Clear, amber dry appearance

Uses: Extremely strong bond; should bee sed only to fasten metal to wood. Expensive. Must be used quickly after mixing.

Painter's tape, throwaway paintbrushes, and other similar materials are important to have in the workshop, even though they are not frequently used. Let's review their many uses in the next section.

Types of Steel Wool

Which wool you choose for your project depends on what kind of job you need done.

Medium Wool

1 grade; Coarsest grade for furniture.

Used with chemical paint and varnish remover, used to remove finishes.

Medium Fine Wool

0 grade

Used with paint and varnish remover to rub spots off finish in final stripping stages.

Fine Wool

00 grade

Used to prepare wood for finishing; can also be used to dull a shiny finish.

Extra Fine Wool

000 grade

Used as an abrasive between finish coats; also used to remove stains from finish.

Superfine Wool

0000 grade

Used for final rubbing of finish. Also used to remove stains, and for buffing between finish coats.

Workshop Materials: Painter's Tape, Oils, Cloths, Rope

Paint and varnish removers, abrasives, and adhesives are the most frequently used materials in furniture refinishing and repair. Listed below are other basic materials that are used less often, but are still important to have when you need them.

Painter's Tape or Blue Tape. Use this tape for fine-lining when you apply finishes. The tape can also be used for clamping irregular glue joints. Buy two sizes: 1/2 inch wide and 1-1/2 inches wide.

Throwaway Paintbrushes. You can buy very inexpensive paintbrushes to use and then toss into the trash. This may seem wasteful, but the thinner, mineral spirits, or other solvents used to clean brushes are generally more costly than the brush. Also, factor in your time spent cleaning.

Use throwaways for applying base finishes and stain. Do not use them for applying top and finish coats of any material. The more expensive bristle brushes are necessary for final finishes; buy them as needed.

Paste Wax. Hard wax is best for most furniture refinishing jobs. It is available in a variety of wood-tone colors, so you may want to buy just a neutral wax for your shop inventory and then add special colored waxes as projects specify.

Black Wire. Fine black wire is a product you'll use often for many jobs-from rewiring furniture springs to clamping splits in rounds. Get single-strand black steel wire; one roll -- about 25 feet -- is plenty.

Linseed Oil. Oils are used quite frequently in finishing. Since linseed oil tends to become old in the container, buy just a pint or quart of it at the outset and add more as needed.

Mineral Oil. Use it for mixing pigments in furniture refinishing. At the outset, buy a small bottle. Then add more if your finishing schedule requires mineral oil.

Turpentine. A quart at a time is enough. Use it for finishing cleanup and for thinning some solvent-base finishes.

Mineral Spirits. Use it for cleaning wood, for finishing cleanup, and for thinning some solvent-base finishes. Again, a quart at a time is plenty.

Denatured Alcohol. A quart in inventory is plenty. It can be used to remove and/or test shellac finishes and to thin shellac for sealing and finishing.

Lacquer Thinner. Good for removing lacquer finishes and for cleanup purposes. A quart on hand will do the job.

Wood Fillers. Wood fillers include wood plastic, water putty, shellac sticks, putty sticks, and colored wax scratch-mending sticks; spackling compound is also useful for filling rough edges. Keep a small can of neutral wood filler on hand; it dries out quickly. Buy wood-tone wood filler as you need it for matching purposes. If you can't find a matching color, mix a drop or two of stain with the filler. Wood filler has no structural strength. Before you use it, clean the wood with mineral spirits.

Water putty is sold in powder form and mixed with water to a thick paste. It dries hard as stone and can be shaped with cutting and smoothing tools.

Shellac sticks, putty sticks, and wax scratch-mending sticks are available in many colors; buy them as you need them. You may or may not need spackling compound, but in powder form, it costs very little and doesn't deteriorate. Keep a small package on hand for use on the rough edges of unfinished furniture.

Clean Cloths, Towels, and Sponges. You'll need plenty of these for all refinishing work.

Tack Cloths. Tack cloths are used often in the wood refinishing process to clean the piece just before applying the finish. You can buy tack cloths at paint supply outlets, or you can make your own.

To make your own tack cloth, launder a white cotton dishtowel. The size should be approximately 12x24 inches, but this isn't critical. Soak the towel in clean water and wring it as dry as you can; then fold the towel in several layers to make a pad.

Pour several ounces of turpentine over the folds and work the cloth in your hands so the turpentine thoroughly penetrates the cloth. The turpentine should just moisten or dampen the material; do not soak it. Pour several ounces of varnish into the folds of the turpentine-dampened cloth, and work the varnish through the cloth to distribute it evenly. This takes a lot of wadding and kneading, so don't give up too quickly. When you're finished, the cloth will be very tacky, not wet or damp, just tacky to the touch.

Tack cloths tend to dry out as you use them. Renew the tackiness with several drops of turpentine and varnish. Keep tack cloths in closed jars or plastic bags to prevent them from drying out. To use a tack cloth, wipe it across the surface you want to clean before you apply the finish.

Bleaches. Borrow the laundry bleach when you want to remove old stain or filler. For tougher jobs, such as removing black watermarks, you'll need oxalic acid crystals or powder. Oxalic acid is not available in all areas; if you can find it, buy a few boxes. If you want to bleach out a wood's natural color, you'll need a two-part commercial wood bleach-it's expensive, but no other bleach does the job.

Aluminum Foil. Foil can be used in a number of ways to keep strippers from drying out.

Rope, String, Toothpicks, etc. Buy these in bulk to have on hand for a number of uses.

Wood. For replacing furniture components, use any piece of wood that's the right type and size: an old table leaf, a birch dowel or broom handle, an ash or hickory tool handle, an ash baseball bat, a piece of maple butcher block, an old pine board. Don't ever throw away old wood with a patina or scraps of hardwood; even small scraps are useful for glue blocks and braces.

Many materials have redeeming features when it comes to furniture restoration and repairs, so make sure to include them on the must-have list for your workshop.