|CWB August 2000
‘Going by the Numbers’ to Repair Damages in the Finish
Mac Simmons classifies three types of damages in finishes and gives tips on achieving successful repairs.
By Mac Simmons
Some professionals in the finishing repair and restoration business define and classify different types of damages according to a simple system. Using this uniform damage numbering system helps the pros describe all damages by using only three numbers. Knowing what each damage number represents allows them to understand the extent of the damage and what materials may be needed for repairs. This article will describe this basic classification system, as well as some of the materials and procedures that can be used to do finishing repairs.
The three types of damages can be easily identified, and using the numbering system can be useful in explaining damages to be repaired if you are turning over the task to someone else. The system still allows us to use routine and familiar names like dents, chips, scrapes or gouges, adding the numbers to best express the problem, whether there are minor or major damages that need to be repaired.
The three types of damages are as follows:
Because all finishes are not the same, you must first make an evaluation of both the type of finish used and the type of damage incurred before you can begin a repair. The more finishing coats that were applied, the thicker the coatings and the more you can sand or rub to remove scuff marks, scratches and defects such as blushing and water or alcohol stains. The thinner the finish, the more care you must take when doing any repairs, as the thinner the coatings, the less sanding and rubbing you will be able to do.
All finishes that have colors added, like toners, glazes and shading stains, must be carefully rubbed and sanded, as you can remove their colors and then create other problems.
You also must consider the sheen of the piece you are repairing, because that also is important in matching the repaired area to the rest of the piece.
You should also be aware of the thickness and sheens of the coatings before you begin working on any damages. And beware — many damages start out small but, because of too much aggressive sanding and rubbing, they become worse. Care and consideration should be in your thoughts before you decide on the grades or grits of the sandpapers, steel wool or any other abrasives you decide to use.
Regardless of the type of damage to be repaired, there are three basic steps in the conventional repair process:
No matter what type of damages you have to repair, each one of these steps must be done correctly to achieve a good repair. Each step is dependent on the others. If the initial repair step is not done right, then you cannot proceed to the coloring step. And it is only when you achieve the right color that you can move on to the next step and adjust the sheen. A bad fill cannot be hidden by the correct coloring, nor can the right sheen make a bad repair look good. All of the steps must be done.
Also remember that a good repair should not change the look or the appearance of the piece. Never try to make a new piece look old or an old piece look new. If you change the sheen in a finish repair and it doesn’t match the rest of the piece or matching pieces, it will stand out and be obvious that the piece has been worked on.
When it comes to choosing your repair materials, there are many items you can use. The different fillers used for repair work include soft and hard wax sticks, burn-in sticks, clear liquid resins, water- and solvent-based fillers, epoxy and polyester body fillers, sawdust and glue, sawdust and epoxy or plaster of paris. All have their place in doing repairs, and selecting the right material depends on the type of damage and the time you have to spend on the repair.
When filling in a damaged finish, the more filler you apply and allow to remain on the area, the more excess filler you will have to remove. (Most secondary damages are commonly caused because of using excessive filler and then trying to sand it level.) Always allow the filler to harden and allow for shrinkage. The filler must be flat and leveled to the surface before you move on to the next step.
Coloring out the damages can be done with touch-up markers, grainers, aniline or pigmented dry powder stains, bronzing powders, pigmented paste colorants, colored glazes, air brushing in colors, aerosols with dye or pigmented colored toners.
When coloring in a damaged area, do not start with a darker color, as it is easier to go darker than lighter. Thin out the colorants and touch-up medium so you do not cause a lip or high area where you apply the color, graining or distressing. Use the brush as dry as possible, so you do not get a buildup of color and medium — this makes it more difficult than if your touch-up color is flat and level. It also will make the sealing and clear coating go faster.
Always coat over your coloring so you can see the true and final color of the repair. Once the coloring is matched to the surrounding area, you will be ready to adjust the sheen to blend in with the rest of the piece.
Sheen adjustment can be accomplished with different grades and grits of steel wool, sandpaper, nylon rubbing pads, sanding and polishing abrasives, rubbing and polishing compounds, waxes, polishes, polishing powders like pumice and rottenstone, jewelers rouge, wipe-on oil- and water-based finishes, French polishing, padding lacquers or clear aerosols in various sheens.
You also can use almost all coatings and their solvents for both color touchups and sheen adjustment just by altering the amounts of coating and solvent — the more solvent you add, the less sheen in your touchups.
All of the coatings, coloring and touch-up mediums used for sheen adjustments must be compatible with each other. Be sure the coatings, colorants and touch-up mediums are dry before you start the sheen matching. Use care whenever you sand and rub on the coloring, edges or corners of the piece, so you do not rub through the finish or the coloring. Matching the sheen to the rest of the piece is a big part of what makes a good repair.
If you follow these three basic steps, you will get good results when doing repair or restoration work. You may also find the damage numbering system useful for yourself and fellow finishers as well as when you have to explain your charges to customers, as a way to describe the extent of different types of damages.
Mac Simmons is a freelance writer who has contributed several articles to professional finishing magazines. Now retired, he is a 40-year veteran of the furniture finishing, refinishing and restoration trades, including 30 years as a field representative for Mohawk Finishing Products. Questions may be directed to him in writing c/o CWB, 400 Knightsbridge Pky., Lincolnshire, IL 60069.