Five Star Painting Franchise

Service Temperatures

Here is the scale for the maximum service temperature for paints:

• Latex and oil: 200˚F or 90˚C
• Epoxies: 300˚F or 150˚C
• Aluminum: 400˚F or 200˚C
• Inorganic Zinc: 750˚F or 400˚C

*These products will fail if they are exposed to temperatures higher than listed above.

Thermal Tack

Thermal tack is caused when the humidity and temperature rise enough to make the coating soften on latex gloss and semi-gloss paints. Even if the paint was applied a long time ago, this problem may still occur. The surface will become tacky to the touch initially, but will go away once the temperature and humidity drop. In areas where this might happen on a frequent basis, it would be wise to paint front doors and jams in an oil based paint instead. If the doors become tacky, they tend to stick to the weatherproofing and cause a mess.

Paint Viscosity

The thickness or viscosity of the paint depends greatly on the temperature of the paint. When a paint is colder, the molecules huddle together as if they were cold, which makes the paint thick. When you try and apply that paint to the wall, it will tend to sag and will not flow very well because of its viscosity level. On the flip side, warmer molecules want to spread out, which almost thin the paint. Because of this, the paint will go on too lightly and you will have problems with coverage. For the best results, try and regulate the temperature of your paint by having it be between 70˚F or 21˚C and 77˚F or 25˚C before you start to paint.

Sheens and Touch Ups

Touching something up can sometimes be a difficult thing to do. It is quite dependant on the sheen, the type (latex or oil), and the age of the paint. First, let’s talk about oil paints. Oil eggshell and semi-glosses will lose a quarter to a third of their sheen after about three months. Trying to touch up a surface that has been painted with that type of paint after the three months could be very obvious. It is better to repaint the entire area instead of just touching it up. Latex paints also tend to lose their gloss, but at a much slower rate and quantity as oil paints. Latex paints are easier to touch up, but remember that you might have some flashing depending on the amount of time since the original paint was applied. With oil and latex paint, you also might run into the problem of fading paint due to sun or other environmental issues. Fortunately, both oil and latex flats are the easiest to touch up, even after a period of time. A quick tip: using an HVLP to touch up the surfaces seems to blend the sheen differences the best.

Temperature Ranges

Be sure to do any touch ups to a surface at the same temperature in which the original paint was applied. There is a rule of thumb in the painting world, that you should not paint any surface below 50˚F or 10˚C, or if that surface will dip down below that temperature at night, until the paint has sufficiently dried. There are, however, some paints out there that have been developed to extend the exterior painting season that will allow the paint to be applied in 35˚F or 2˚C, (ICI’s Fortis and This Old House). If you do touch up something under the recommended temperature, it might dry a little lighter than the original paint. Therefore be sure to apply the touch up paint at the same temperature in which the original coat was applied.

Touch Up Applicators

(This is especially true for smooth walls.) If you are going to touch up a surface, make sure that you use the same applicator as was used originally. Different applicators leave different finishes on the surface. It would be very obvious if there were a brush mark in the middle of a rolled wall. Try and be consistent with the applicators you use and you will find that you will have better results. The more the wall is textured, the easier it is to touch up using any tool, even using a brush over a rolled surface.