Advice and Tips



Popular Questions - Interior

Basement Walls

+Q. What is the best primer for concrete walls for a basement?

A. This will depend on whether there is water getting behind the walls and getting through as moisture and/or in carrying white salts (efflorescence) to the surface. If water is getting behind the walls from ground water, rain, etc., first try to direct rain away from the base of the building by building up soil to the wall to aid run-off, and be sure gutters and down spouts are clean and in good repair, and that down spouts carry rain water well away from the walls.

In any case, if there is water, apply a basement waterproofing coating to the walls. Solvent based, cement-containing products are effective, but ample cross ventilation must be used during and right after application; and wear eye protection and an appropriate respirator. Follow directions as to method of application, and spread rate (sq. ft./gal.). After the water-proofing product has cured for at least a month, apply an all-purpose latex stain-blocking primer, followed by your finish coat. There are water-based water-proofing coatings now available too... follow manufacturer's directions closely. If the wall are free of intruding water, apply an all-purpose latex stain-blocking primer directly to the walls after cleaning them.

Skinning avoiding

+Q. I am using an oil based primer on wood in my house. What can I do to prevent a skin from forming on the paint after the can has been closed? I heard that putting a sheet of waxed paper over the paint in the can and then sealing the cover will do the trick. Is this true or is there something else I can do?

A. The first thing to do is clean out all primer remaining in the groove or "chime" of the container. Make sure that the rim of the lid is clean, too. Then, do one or the other:

  1. press the lid on and make sure it is presses into place thoroughly. (The smallest hole will allow air to enter and leave with changes in the air pressure, and thus foster skin formation.) Then store the container upside down.


  1. place a circular piece of clear plastic wrap carefully on the primer in the container, then press the lid on tightly, and store the container upright.


+Q. Can a quality latex paint be hurt if it has been frozen and thawed?

A. Yes, latex paint can be hurt if it is frozen. Problems that can occur are reduced gloss, separation of ingredients, formation of "grit" or lumps. Often, though, a paint may survive one or a few freeze-thaw cycles. If a paint is frozen, it should be thawed slowly; then thoroughly stir the paint. If it appears to be smooth and of normal consistency and of the proper color, it probably is OK to use.


+Q. What is the difference between paint thinner and solvent?

A. Solvent is a general term used for different organic liquids. Examples of some used with paints and coatings are lacquer thinner, paint thinner, naphtha, denatured alcohol, turpentine. Paint thinner is a specific solvent used with oil based paints, stains and varnishes. Paint thinner is made mainly from a solvent called mineral spirits. Paint thinner is similar to "lighter fluid" and "charcoal starter". Paint thinner is less flammable than lacquer thinner and gasoline.


+Q. What is titanium dioxide?

A. Titanium dioxide is a white substance used as a white pigment in paints, plastics, paper coatings, non-dairy creamer, etc. It is exceptionally efficient in scattering light (much more so than other white pigments such as clay, calcium carbonate and zinc oxide), and maintains its whiteness when made wet (as in a flat wall paint that is washed) or put into a paint even that has a high level of binder. It replaced lead compounds as the primary white paint pigment shortly after WW II. It is used in white, gray and light and medium color paints. Titanium metal is familiar used in golf club heads; the oxide is white, and is sold to paint manufacturers as a powder in 50 pound bags, and as a slurry in water in tanktrucks and tankcars.

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