SOLVENTS: Finish Thinners as Cleaning Agents
Lacquer Paint Other Solvent Thinners can be used to clean certain finishes with care. Whether to use paste wax or furniture polish to protect.
Finish is thinned with materials designed for each type of finish. Different thinners are compatible with different finishes.
- The thinner for a finish type cannot be used to clean soiling from that finish, for example do not use lacquer thinner to clean soiling on a lacquered item.
- Finish thinners are also called solvents when used as a cleaning agent, or when being used to clean soiling from an existing finish.
- Different solvents work for different soiling and on different types of finishes.
Finish, thinner, and solvent compatibility is crucial: If you apply or clean a finish containing a solvent that softens and blisters the underlying stain or finish, it may partially strip or remove that finish. For example lacquer or lacquer thinner over varnish can cause damage to the varnish.
- On the same basis if you apply a finish containing a thinner that has no effect on the underlying stain or finish, you may still not achieve a good bond between the old and new finishes. Varnish, for example, doesn’t bond well to itself or other finishes. Polyurethane is a type of varnish.
Which solvent to use as a cleaner on which finish is extremely important:
- Mineral spirits, naphtha, turpentine are solvents for wax, and thinners for wax, oil and varnish finish. They dissolve solid wax, but they do not dissolve cured oil or varnish/polyurethane.
Neither do they dissolve any other clear furniture finish, so they are used in furniture polishes and cleaners. Naphtha is best for degreasing.
- Denatured Alcohol is a solvent and thinner for shellac and a weak solvent for lacquer and water base. It will dissolve lacquer and water base, but very slowly. Alcohol won’t damage reactive finishes such as varnish/polyurethane.
- Lacquer thinner is a solvent and thinner for lacquer and a thinner for catalyzed lacquer. It is also a solvent for shellac and water base. It will re-dissolve these finishes after they cure. Lacquer thinner will soften and sometimes blister reactive finishes, but it won’t dissolve them.
- Acetone is a solvent for white/yellow wood glue, cyanoacrylate and hot melt glues. It will damage lacquers and varnish.
What kind of finish do you have? You can take advantage of the ways different solvents react with different finishes to identify an existing finish. Proceed as follows:
- Apply a few drops of denatured alcohol to an inconspicuous spot. If the finish becomes soft and sticky within seconds, it is shellac. If it doesn’t, the finish is not shellac.
- Apply a few drops of lacquer thinner in an inconspicuous spot. If the finish becomes soft and sticky within seconds, it is shellac, lacquer or water base. Since you’ve already ruled out shellac, it is either lacquer or water base. Don’t forget there is a water-based version of lacquer that came into limited use after 1990 or so.
- To distinguish more definitely between lacquer and water-base, apply a few drops of toluene or xylene. If the finish softens, its water based and not pure lacquer.
- If none of these solvents dissolves the finish, it is a reactive finish. You don’t know which one, but it rarely makes any difference.
KINDS OF FINISH BASED ON HOW THEY CURE:
- Evaporative finishes use solvents that evaporate: shellac, lacquer, and wax.
- Reactive finishes use mineral spirits or naphtha: linseed or tung oil, varnish, polyurethane, all-in-one stain-seal-finish, glaze.
- Coalescing finishes use ether or water: water-based finishes.
CLEANING A FINISH (that is physically sound):
- Mineral spirits or naphtha, as a solvent, can generally be used to clean bad soiling like on the tops of dining chairs, remove body oil and food soiling on table tops, or the build-up of polish.
- Furniture finish can also be cleaned with mild natural soap and water. Ivory and Murphy’s Oil Soap won’t damage sound finish, but excessive water will.
- If after such cleaning there is no or little finish left behind it is because the finish was not physically sound due to damage from the soiling being removed. We suggest paste waxing.
PROTECTING A FINISH:
Paste wax does not evaporate. Liquid furniture polishes that don’t contain wax, and most don’t, do evaporate. Paste wax will continue to provide wear protection and shine until it is worn or washed off. Wax-less polish will provide wear protection and shine only until it evaporates.
- Until fairly recently beeswax was the primary furniture care wax available because it was the only wax available. Now there are natural and synthetic waxes available that can demonstrate more sheen.
- All waxes are solid at room temperature so they are called paste waxes. While rarely done, they can be thinner with turpentine.
- Some paste waxes are available in colors. The color is dye or pigment that can lie in the grain. They can be used to color in nicks and scratches while waxing. Colored paste waxes won’t add any noticeable color to the general finish.
Commercial paste waxes are often made by blending several individual waxes for cost, color and slip resistance (for floors) and vary in their hardness, gloss, and melting point.
- Generally the higher the melting point the harder and glossier the wax.
- Carnauba wax melts at about 180 degrees.
- Beeswax melts at about 140/150 degrees.
- Paraffin wax melts at 130 degrees.
Wax build up is a myth. Each time you apply a new coat of paste wax, the solvents in it dissolve the existing wax, making one new mixture. Buff off the excess and you’re back to the original thickness of wax.
Some paste waxes include: Johnson paste wax, Trewax, Minwax finishing wax, Butcher’s wax, Briwax.
Basically all have no noticeable difference in sheen or hardness. Few use the old fashion beeswax because of its high cost.
Briwax contains toluene. This solvent is strong enough to dissolve and remove many finishes if they haven’t thoroughly cured or are damaged. The container instructions for each brand should be carefully followed for how long to wait, or not wait, before wiping off the excess. If you catch the wax just as the sheen changes, the excess will be easy to remove. If you wait too long, you will have to rub very hard in order to build up enough heat (about 140/150 degrees) to melt the wax so the excess can be removed. On the other hand, if you’re too quick, you’ll remove the wax together with the solvent involved.
- If you want a low sheen wax result, wipe off the excess with 0000 fine steel wool.
- If the wax dries too hard to make removal difficult, apply more paste wax to soften the original wax and then remove the excess.
- Remove soiled wax with naphtha or mineral spirits.
Most furniture polishes are made from petroleum distillate solvents in the range between mineral spirits and kerosene. The difference is the rate of evaporation based on the contents. The petroleum smell is replaced with a lemon or orange additive for a more pleasant smell than kerosene, for example.
- Furniture polish adds: temporary scratch resistance, temporary sheen to a dull surface, aid in picking up dust, clean grease and sticky fingerprints, fill the room with a scent.
- Furniture polishes do not: feed the wood by replacing missing oils that never existed, feed the finish, protect against heat water and solvent or other chemical damage, slow deterioration cause by light or oxidation.
Common furniture polishes include: Endust, Formby’s furniture treatment, Old English with lemon oil, Pledge, Kleen guard, Guardsman furniture polish, and many contain lemon or orange scents for a more pleasant smell.
The content of this paper is based on Bob Flexner’s “Understanding Wood Finishing”. We thank him.
10059 Hemlock Drive, Overland Park, Kansas 66212;
Off of 103rd Street, Hemlock is 1st east of Antioch or 1st west of Lowell Ave west of Metcalf; and turn north up curvy Hemlock Drive 1/2 mile.
This is a residence. Please park in driveway. Respect the neighbors.
They are shown in the left column of this and every page.
Cash, Check, or Credit Card shown
in the left column of this and every page.
Down-Payments are required on all orders.
- Disclaimer: Unless otherwise stated, this document was created and written by staff of the Wood Works, Inc. and therefore is protected by applicable copyright laws. The information presented here is based on years of industry experience in addition to information obtained from publicly available sources, including company websites, industry peers and industry publications. There may be inaccuracies and information that has become outdated since this white paper was originally written. This information is intended strictly for informational purposes.
- Reproduction of this document in whole or part may be done without written approval but must reference this document as a source and display one of the following URLs as the location to obtain the full report: http://www.thewoodworksinc.com or http://www.themovingclaims.com. Thank you!
- The Wood Works, Inc. Corporate Logo holds a national trademark. The Corporate Name of "The Wood Works, Inc." holds a national service mark. Accordingly, neither can be used by another for financial gain.
The entire website/s of www.TheWoodWorksInc.com and www.TheWWs.com and www.TheMovingClaims.com are copyrighted and should not be used by others in the trade in any form without explicit written permission.