SAVING THE FINISH

By Jeff Jewitt

Sooner or later, every woodworker is faced with the prospect of refinishing an oldpiece of furniture. Whether it's a treasured "find" at a flea market or auction,or a favor for a relative or friend, etc., most people consider stripping off the oldfinish and refinishing the only option of successfully restoring the appearance of thepiece.

When many woodworkers see an old dirty finish, their first thought is to remove it. Insome cases this is the best approach as I will explain below. However, most old finishesdo not need to be completely removed to restore the appearance of old furniture. Much ofthe patina on old pieces is on the outer surface of the wood under the finish and is theresult of exposure to sun and air. The chemicals in most strippers "pull out"some of this patina which can affect the desirable characteristics of an old piece.Strippers can also affect the glue in joints and loosen veneer. Museums and conservatorsof antique and historically important furniture rarely remove a finish and will only do sowhen the finish has degraded to the point that the stability of the piece is jeopardized.Most of the time, the finish is partially removed which involves the removal of thedamaged surface layer only. Almost all techniques involve some type of cleaning andremoval of accumulations of dirt, oils, and old polishes from years of use.

Since many of the pieces that come into my shop are antiques, most of the work that wedo centers on saving the original finish. While some techniques call for specializedsolvents and chemicals, there are several techniques for cleaning and restoring an oldfinish to the point where the piece once again looks good. My background in conservationhas taught me several cleaning and conservation techniques that can be used by mostwoodworkers to restore a piece of furniture without stripping the finish. In this article,I'll detail several of these techniques that can be done by most woodworkers with aminimum of specialized materials. Before we start, I'd like to discuss those finisheswhich shouldn't be saved.

FINISHES THAT CAN'T BE SAVED

Not all old finishes can be saved. Finishes that are severely damaged or degraded tothe point where they can no longer effectively do a good job of protecting the wood shouldbe removed. Although most conservators would like to save the original finish whenpossible, finishes that have degraded to the point where the wood is in jeopardy should beremoved. These situations include severe water or heat damage, large losses of the finishwhere the wood is exposed and situations where the finish is severely discolored. Anotherfinish that cannot be saved is a finish that is sticky. Sticky finishes are those thathave become chemically altered to the point where they will never fully harden. Severewater or heat damage appear as large white areas where the finish is peeling or flakingoff. Large exposed areas of wood are very difficult to blend in without highly developedskills so removal of the entire finish is called for. Another problem finish is one inwhich the finish has been mixed with pigment and applied thickly. Old varnishes andshellacs applied in this manner may develop large cracks or "islands" which showthe bare wood below. This finish should be removed in most cases. An exception are crazedor cracked finishes where the cracks do not go all the way through to the wood below. I'llexplain how to deal with this later.

The goal in restoring an old finish is not to make it look brand new. At best thistreatment should restore as much of the original condition as possible and prevent furtherdeterioration. While by no means is restoring a finish a "quick-fix" type ofrepair, on most pieces it should be less time-consuming and expensive than a completestripping and refinishing. In addition, you do not run the risk of ruining the value of anold piece of furniture by removing a piece of its history. The following are the steps insaving an old finish. Sealing damage, cleaning, abrading the old finish (if necessary) andfinally waxing.

SEALING DAMAGE

Damage that needs to be sealed are dents, scratches and small areas of finish that havebeen worn away. The cleaning process involves water and solvents that could possiblyaffect bare wood and it should be protected. For sealing, I use a 2 lb. cut light-coloredshellac. Using a red-sable artist's brush, I brush several light coats of shellac to thedamaged area and then let the shellac dry overnight. Do not try to match the color to thesurrounding finish at this point. The cleaning will lighten up the color so blending in atthis point will result in a mismatch.

CLEANING

Before cleaning, it helps to know what the finish is so that the appropriate cleanerscan be used. I test the finish by a three step process using various solvents. Find aninconspicuous spot such as behind a leg and dab a little denatured ethyl alcohol on thefinish with a small brush or cotton swab. After thirty seconds tap the area with yourfinger - if it's sticky the finish is shellac. If the alcohol doesn't affect the finishtry a little lacquer thinner. If the finish still isn't sticky, it is probably anoil-based varnish or polyurethane. Knowing which finish you have minimizes possible damagefrom cleaning solvents as we will see later.

Cleaning is a two step process which removes both water-soluble and oil-soluble dirtand grime. The first cleaning step uses a hydrocarbon based cleaner like mineral spiritsor Stoddard solvent. I prefer to use VM&P Naphtha rather than mineral spirits becauseit flashes or evaporates much quicker. It's important to test a small amount of thecleaner on an inconspicuous area. Certain oil-based finishes varnishes can irreversiblywhiten on exposure to some hydrocarbons so testing is crucial and it's important to knowwhat the finish is. Oil finishes may soften and be completely removed, but in most casesVM&P Naphtha has proved the best all-around solvent in my use. Dampen a clean clothwith the Naphtha and rub a small surface at a time. Do not saturate the surface. Switch toclean cloths frequently.

The next step involves using a detergent mixed with distilled water. I use Triton X–100. This is an extremely concentrated non-ionic detergent. I use a 3% solution byvolume. An alternative to Triton is Dawn - a commercial dish-washing detergent that isreadily available. I use a solution of one capful in a pint of luke-warm water. Apply thesolution with a dampened clean cloth, (not dripping wet) and rub a small area at a time.The Triton works very quickly while the Dawn may work a little slower. You'll see yourprogress by the dirt on the rag, so change the surface frequently. Afterwards, wipe allthe excess detergent off with clean water and proceed to the next step.

ABRADING

The cleaning above removes the surface dirt from the finish but it still may be hazy orwhitish. Part of this problem may be from small crazing or cracks in the finish whichreflect light - making the surface appear dull. If this is the case and the cracks do notgo all the way through to the wood, abrading part of the finish will remove most of thecracks. I use stearated sandpaper, (sandpaper mixed with zinc stearate to minimizeclogging), to abrade away a portion of the finish. I start with 240 grit and proceed to320 grit and finally 400 grit. I back the paper with a felt or cork block and avoid theedges since it's easy to cut completely through the finish. I strongly recommend wearing adust mask since the dust is irritating. Sand in straight lines with the finish and wipethe residue off frequently with a Naphtha dampened rag. You can stop sanding when thegrain of the wood is visible or when the cracks have disappeared. Patience is requiredbecause a heavy hand will cut through the finish and you'll have no choice but to strip atthat point. Wipe the piece with Naphtha and let dry overnight.

WAXING

The piece is now ready for the final step. I prefer to wax and buff out, but if youwant, you can apply a light coat of whatever finish you prefer. Shellac or varnish willboth work over most finishes but shellac should be used if the piece is an antique. Iwould avoid polyurethane because it will not bond very well to an old finish. Either way,you may need to do a little touch-up first. There may be small areas where the finish isremoved down to the bare wood. These should be sealed with several coats of a 2 lb. cutshellac applied with an artist's brush or a small varnish brush. After drying these, areascan be blended into the surrounding area using shellac mixed with dry artists pigments.After drying, seal all repaired areas again with a 2 lb. cut shellac.

For the final waxing, I prefer a good quality furniture wax like Briwax, Behlen, orAntiquax. All these waxes come in clear and dark brown, and Briwax has golden oak, redmahogany and light brown. I prefer the colored waxes because any wax that lodges increvices or small defects will not be noticeable when dry. Put a scoop of wax inside aclean cloth and apply the wax in a small circular motion. On turned areas, carvings andother irregular areas, work the wax in with a stiff bristle brush. Work on a manageablearea at a time and when the wax hazes buff it out using a clean cloth. After dryingovernight, give it a second waxing.

When the second coat dries you'll have a restored finish without the bother or hassleof stripping. You'll find it's much less work and the result is that you haven't possiblydetracted from the value if the piece is an antique. As an added bonus, you find that theentire process can be done in one weekend, rather than two or three weekends. And finally,the piece will have retained the patina that took so long to acquire with time. And thetime you saved can be spent admiring your furniture.

Jeff Jewitt is a finisher, writer and teacher from North Royalton Ohio. In addition torunning a full-time finishing shop, he has written numerous articles on finishing for FineWoodworking, American Woodworker, Popular Woodworking, Woodshop News and ProfessionalRefinishing Magazine. He is currently a technical editorial advisor forProfessional Refinishing magazine, acted as a consultant for large finishing companiesand has developed finishing products which are sold all over the world under the Homesteadname. He is the author of Hand Applied Finishes and two videos, ColoringWood and Applying Topcoats (Taunton Press) and is currently working on a new book dueout in late 1999.

Jeff Jewitt owns and operates Homestead Finishing Products – featuringhard-to-find traditional finishing products. 5 Grades of dry shellac, oils, varnishes,brushes and their own exclusive line of dyes make Homestead Finishing Products a must forevery restorers supply needs. Excellent technical advice. Please contact us by:

Homestead Finishing Products
PO Box 360275
Cleveland Oh 44136-0005
Phone: 216-631-5309

Also available are Jeff’s Book Hand Applied Finishes, and two videos, Coloring Wood and Applying Topcoats – winners or the 1997 Stanley Award for best How-To book and video.

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