When making service calls, how can a topcoat be applied to a surface that is larger than a typical touch-up area (such as the entire top of an end table) without creating an offensive odour in the home or office?

Use Wipe On Water Base Urethane. It is rag applied thus avoiding any over-spray, has very low odour, will adhere to most other finishes, and will not lift other finishes.

How can lacquer be made to flow to a smoother surface without significantly extending the dry time as with the use of retarder?

A: Use Flow Out Extender. Because it functions in the early stage of the drying cycle (extending the time when the lacquer is flowing), it facilitates a smoother finish and eliminates over-spray, However, once it has done its work, it evaporates out of the lacquer thus allowing a normal dry time. 
B: Reduce with 5 to 10% reducer for better flow-out.

Why does lacquer stay tacky in the grain pattern of open grain woods (i.e. Oak, Walnut, Mahogany) on refinished pieces?

Residue from the stripper is probably caught in the pores of the wood. This residue can keep the lacquer from drying properly. Great care must be taken to clean the stripper out of pores, not merely off the surface. Use a brass wire remover brush to scrub the surface with Lacquer Thinner.

I used Wipe On Water Base Urethane to apply colour on a touch-up, and then sprayed aerosol lacquer over it. The repair area developed a fine crackle. What happened?

The solvents in the lacquer can cause the Wipe On Water Base Urethane film to crack in some cases. Allowing the Wipe On Water Base Urethane to dry more thoroughly and applying very thin, light coats of the aerosol may avoid this problem. Since the Wipe On Water Base Urethane itself is a good topcoat, generally it does not require any other finish be applied over it.

When I wiped Wipe On Water Base Urethane onto a piece of cheap furniture with a "paper" finish (photo finish, foil, etc.) it seemed to "crawl" or fisheye at the edge of the wet Finish up. Why did this happen? What can I do to avoid it?

Because this is a water-based product, it has a surface tension similar to water. This finish may have some residue from a "release coating" used in the manufacturing process, which causes the water to try to "bead", in the same way that water beads on a well waxed car. Use De Waxer 741 or Wood Stain Reducer to remove the coating, or lightly scuff with 4/0 steel wool (if you can do so without taking off colour) or you can sometimes simply rub hard with the cloth dampened with Wipe On Water Base Urethane, dry the area, then wipe on a wet coat of Wipe On Water Base Urethane.

After spraying finish coat of lacquer, small air bubbles appear.

This problem, referred to as "blistering", "gassing" or "bridging" can be eliminated a combination of: A: Applying lighter, multiple coats of finish. B: Reducing finish with a slow drying reducer or introduce more retarder into finish. C: Adjusting spray pressure.

I can't tell if a piece to be touched up has a catalysed finish or not, thus not knowing what type of material to use.

Take a rag with a small amount of lacquer thinner and rub in an inconspicuous spot. If the finish softens or comes off, then it is not a high performance finish and conventional touch up lacquers can be used.

Applied a coat of Por-O-Pac Paste Wood Filler as directed but the grain is not completely smooth.

Although Por-O-Pac paste fillers are very high in solids, they are not 100% solids. Therefore some shrinking is to be expected. A second coat of filler may be required. Also, minor grain depressions can often be levelled by the sealer, followed by sanding. NOTE: do not use more than 2 coats of sealer or try to substitute sealer for filler!

Applying 545 Wood Stain over Por-O-Pac Paste Wood Filler. It seems to be softening and removing some of the filler.

Solvents in the stain are compatible with the filler. If stain is applied wet, it could soften filler. Apply a wash coat of sanding sealer over the filler, sand lightly, and apply stain.

Applied Heavy Body Glazing Stain over sealer. The next day when the finish was applied it wrinkled.

Resins in the glaze begin to polymerise and have a recoat window. Lock in glaze with a light coat of lacquer or sealer within 1 to 6 hours from time glaze was applied.

Used Heavy Body Glazing Stain on a piece to add detail and create an antique look. Places where glaze was applied heavily seem to chip easily.

Glaze left on in heavy layers form a layer of material between sealer and lacquer coats. This results in a more chip sensitive finish. Best to use glaze in thin application where durability is required.

Sealer is not drying - gums sandpaper.

Sealer was applied over wet wood. Or: Applied over contaminated wood. Or: Applied when humidity and temperatures were very high. Or: Left to dry in area where cold temperatures were predominant. Or: Applied over insufficiently dry stain. Or: Incorrect reducer was used. Or: Excessive amounts of retarder were used. Determine the source of the problem and take corrective measures.

Sealer turns white when it dries.

Blush (moisture entrapment) in film leaves a hazy white appearance. Blush Eraser or Retarder added to the sealer helps eliminate blushing. Or: Sealer applied over an insufficiently dry stain or filler containing mineral spirits can cause a white haze. Be sure stains, etc. of this type are dry before sealing. Or: Applied over wax or oil-contaminated surface.

Several coats of sealer were applied but the grain is not filled.

Sealers are designed to fill pores and provide a foundation coat for lacquer, not to fill grain in open grain woods. Use Por-O-Pac Paste Wood Filler to fill grain.

Lacquer is drying slow or not drying at all.

Weather conditions such as high humidity, rainy cool weather, and cold drying area retard drying. Finishes dry best when relative humidity is between 25% and 50%, air temperature is 18 degrees C to 27 degrees C. If an environmentally controlled drying area cannot be provided it might be best to wait for favourable weather. Or: Incorrect reducer or excessive retarder was added to the lacquer. Or: Lacquer was applied over an incompatible product or one that was not dry enough Or: Surface was contaminated.

Lacquer turns white as it dries.

Usually the result of moisture entrapment (blushing) occurring during hot and humid or damp weather. Add retarder to your lacquer or spray over the finish with Blush Eraser. Or: A delayed whitening effect may be due to surface contamination (wax, oil) or to spraying over a stain containing mineral spirits which was not yet dry. Be sure surface to be sprayed is cleaned free of contaminates and always let stain dry sufficiently.

Lacquer leaves orange peel texture in the finish.

Cold lacquer or cold spraying conditions. Lacquer, substrate and ambient temperature should be at least 18 degrees C. Or: Lacquer is being sprayed at too high a viscosity (too thick). Add the recommended amount of reducer and adjust for equipment. Or: Lacquer is being sprayed during very hot temperatures. Solvents flash off too quickly and don't allow film to level. Add a recommended retarder.

Lacquer leaves craters (fisheyes) in the finish.

Silicone contamination resulting from use of consumer polishes. This is common when refinishing. Surface to be refinished should be washed with Wood Stain Reducer. An application of Shellac can be effective in more serious cases. Fisheye Flow Out can be added to sealer and lacquer to help combat fisheyes. If fisheye Flow Out is added be sure to use it in every additional coat until finishing is completed. NOTE: that these suggestions are aids in combating silicone contamination. Serious contamination may be difficult to overcome even if all three products are used. Or: Contamination from silicone used as a lubricant in a nearby area will result in fisheye problems. Avoid using these products where finishing is done. Or: Wax contamination on surface. Clean thoroughly with De Waxer 741.

Other forms of contamination such as dust, soot, sawdust, etc.

Maintain a clean spray area by practicing proper housekeeping And using common sense. Many minor contaminates can be removed from a finish by fine sanding and/or rubbing.

The Lacquer finish has developed cracks.

There are many things that can lead to cracking of a finish (often it can be a combination of factors). The most common reason is building too many coats too quickly. Follow manufacturer's recommendations for coating thickness and the number of coats to apply. Other factors leading to cracking are using improper reducers, wet substrate (high moisture content), and spraying lacquer over an incompatible material. Most factors that lead to cracking are controllable by the user.

Can I spray Behlen's clear lacquer over an old finish?

A: Qualalacqs Lacquer (clear or coloured)? Yes for both. It will add a durable wear coat.
B: polyurethane Finish? No. Poor Adhesion. 
C: An Oil Finish? Not over fresh oil finish. Possibly over an old oil finish providing it is not a non drying oil and it is cleaned and sanded. (Testing by user is advised) 
D: Another manufacturers sealer, lacquer, or stain, etc. The best advice is to use one manufacturers products for the entire system. Mixing systems can often lead to problems for the user. 
E: Over shellac? Yes, with qualifiers. Lacquer applied over thin coats of shellac is considered acceptable. Thick coats of shellac tend to become brittle as the film ages. 
F: Over a catalysed lacquer finish? Yes as long as it is not applied within the window stated by the manufacturer. If the finish is cured, the surface should be cleaned and scuffed. Only mechanical bonding is achieved.

How can I stop old dye in stripped wood from bleeding into the new finish?

A: For coloured topcoats, apply a thin coat of Shellac. B: For clear coats, the best advice is to bleach the wood.

Why did the finish wrinkle when I sprayed clear lacquer over coloured automotive enamel?

Spraying a solvent based lacquer over an enamel will produce wrinkling. Use auto paints on cars and furniture lacquers on wood.

I don't have your recommended reducer for your lacquer, what can I use for a substitute?

Varying from the manufacturer's recommended reducer is a users decision. Manufacturers refrain from the responsibility of guessing in matters this important.

What will happen if I put Polyurethane over sanding sealer?

You will have questionable inter-coat adhesion. It is preferable to use polyurethane as a sealer and then use polyurethane as a top coat.

What can I use as a finish for over an old oil finish without stripping the piece?

A: More oil finish. B: An oil modified varnish.

How can I tell if some liquid shellac I have had for a while is still good?

If liquid shellac is not fairly fresh, it is recommended you test some on a scrap piece to be sure it dries. Old shellac will stay soft and gummy. Liquid shellac stored at room temperature is usually good for up to one year. If stored at warm temperatures, shelf life decreases dramatically. Storing in a refrigerated area prolongs liquid shellacs useful life and is highly recommended. Dry shellac flakes stored under refrigeration have an indefinite shelf life.

What is the difference between Raw Linseed Oil and Boiled Linseed Oil?

Raw Linseed Oil will never dry completely. When applied as a film, Raw Oil has molecular groups (sometimes called "tails") that remain tacky forever. Boiled Linseed Oil originally was produced by using heat to eliminate these "tails". Today Boiled Linseed Oil incorporates chemical dryers, which are added to promote drying (begin the polymerisation process) in place of the heating process.

What is the equivalent Behlen product to "Bulls Eye French Polish"?

Either Qualasole or French Lac can be used for the same procedures as the Bulls Eye French Polish. If you are padding colour, Lac French is the better choice. If you are applying a French finish, Qualasole is the better choice. However, both can be used for either application.