Did You Know?

Latex Or Alkyd?

To establish if a paint on a surface is an alkyd or a latex, rub the surface with a cloth wet with xylol (or nailpolish remover). Latex paint has very poor solvent resistance and will come off on the cloth. Alkyd paint will not be disturbed by either solvent.

Colour Chips

Most paint manufacturers produce their colour chips in a low sheen and often the architect or owner is surprised when they see the color in an eggshell or semigloss finish because it looks different. To see what a color will look like in an eggshell or semigloss, wet the colour chip with water.

Gloss Vs. Sheen

The gloss and sheen of a paint are not the same. The gloss is measured with a 60-degree gloss meter (60 degrees from the vertical — 30 degree from the surface). The sheen is measured with an 85-degree gloss meter (85 degrees from the vertical — 5 degrees from the surface). An alkyd eggshell, for instance can have a gloss of 15 and a sheen of 35.

How Many Coats?

To establish how many coats of paint are peeling from a surface, measure the paint chips with a micrometer. The typical coat of alkyd paint applied by brush or roller is 1ó-2 mils (thousands of an inch) and the typical coat of latex is 1-1. mils. Dividing the total film thickness of the paint chips by 1.5 will give a good indication of how many layers there are, since there can be a mixture of alkyd and latex used on a surface over the years.

Computer Rooms

There is a requirement in some computer rooms to paint the floor with a conductive coating to help dissipate static electricity. Most paints like alkyds, polyurethanes, epoxies, and latex are not conductive, but are in fact insulators, so they are not suited for this purpose. There are special conductive coatings made by specialty manufacturers. (Check with your local paint supplier.)

Alkyd Primer On Drywall?

With the exception of priming drywall for the application of vinylwallcovering, alkyd primers and paints should not be applied directly to the drywall surface. The solvents in alkyd paints cause the paper nap of the drywall to be raised and the result is a very rough surface that requires substantial sanding before topcoating. Latex sealers, on the other hand, do not raise the paper nap and can be topcoated with alkyd or latex.

N.G.R. Stain

When staining and finishing hardwoods like oak, maple, and birch, consider using an N.G.R. (non grain-raising) stain. These stains dry quickly (5 minutes) because they are just color and solvent, therefore they penetrate better and can be recoated in the same day.

Light Reflectance Value

The light reflectance value of a color is a function of color only. The gloss or sheen of a product does not influence the light reflectance

Exterior Stains

To avoid lap marks when using exterior stains, try to work in the shade as much as possible. Paint only one or two boards at a time, making sure that the stain doesn't dry in the middle of a board during application. Complete the boards from side to side (horizontal siding), or top to bottom (vertical siding), before moving to the next board.

Painting Ceilings

When painting a ceiling, and there is a window in the room, keep the light source at your back and start painting away from the window. This will ensure that you will see any missed areas and reduce lap marks. Note: if there is more than one window, choose the largest one and follow the same procedure.

Lacquer Thinners

Lacquer thinners vary in quality and cost. They are usually a blend of active (solvents that are very compatible with lacquer) and inactive (filler solvents that by themselves will not dissolve the lacquer) solvent. The more active solvent in the blend, the better the quality of the lacquer thinner, the more expensive it will be and the fewer application problems you will have with the lacquer. You also won't have to use as much of it to thin a lacquer for spray application. Do not use recycled lacquer thinner for thinning lacquer. It should only be used for cleaning equipment.

Extending Working Time

When using alkyd enamels on a warm day, it is often hard to avoid brush and roller marks because the paint is "tacking up" too fast. The working time can be extended by adding PENETROL™ to the product. Usually a 10-15% addition is sufficient.

Thinning

Under some circumstances, an applicator may have to thin a product (usually for spray application). Alkyd paints can usually be thinned with solvents like V M &P Naphtha or Xylol. Alkyd quick-dry primers and topcoats cannot, on the other hand, be thinned with mineral spirits. The resins in quick-dry products require a stronger solvent like Xylol to keep them in solution. The result of putting mineral spirits in a quick-dry alkyd can be a finish that is gritty.

Dark Colors

Painting with dark colors on a hot day, or in direct sunlight can cause the paint on the surface to skin over and trap solvent in the film. As the solvent tries to escape, blisters can form in the paint. Repair of these blisters requires sanding and repainting.

Shake Or Stir?

There is a misconception that varnishes should not be shaken or stirred. Shaking varnish causes air bubbles in the can which might take overnight to dissipate. Although there is little in gloss varnishes to settle, flat, satin, and semigloss varnishes contain pigment which may settle out. Using a low-gloss varnish without at least stirring will usually cause a variation in gloss (from glossy to flat) as you get lower in the container.

New Type Of Tip Saves $

New airless spray tips are elliptical in shape, but as they are used, the hole in the tip becomes larger and changes from an ellipse to a circle. In order to maintain the spray pattern, more pressure is required. The more pressure that is used, the more overspray that occurs, and more paint than necessary is used. The price of a new tip can be recovered in saving 2-3 gallons of paint.