FAQ

Usefull information about paints and varnishes, regarding their application, painting procedure, tool selection and troobleshooting.

HOW THE PAINTING CAN BE AFFECTED BY THE WEATHER CONDITIONS

Weather conditions must be taken into account since they play an important role in the success of your work:

  1. a) Avoid painting in temperatures below 10 o C and above 35 o C or when humidity exceeds 75 %.
  2. b) Paints that dry fast and normally are applied by spray gun or even by brush, must be used, when temperatures are high (summer months) away from direct sunlight, while in the winter months they should be done in protected area and during the warmer hours of the day.

For best results, temperature should be between 20 o C and 25 o C.
As concerns the humidity, the average relative humidity in the work area, because of rain or fog, has a negative effect taking longer for the paint to dry.


Water based colors (emulsion paints, water based enamel, etc) are also affected by high humidity and winter low temperatures. Suggested painting temperatures are above 10 o C.

HOW THE SURFACE MUST BE PREPARED

Metallic surfaces must be free from rust, oil, dust, etc. Surfaces made of plaster, concrete, wood, etc. must be free from loose parts and be cleaned up from dust or dirt. In all cases, the surface must be dry and clean before application of the paint. If we want to paint metallic surfaces where sandblasting is required, it is important to apply one coat of anticorrosive primer at the same time the surface has been sandblasted and cleaned. Examples of different degrees of cleaning of a surface using sandblasting can be seen below.

APPLICATION PREPARATION

Stir the paint well before its use making sure that there is not any pigment left at the bottom of the tin.Dilute according to the suggested type and ratio of diluent (solvent or water), making sure that the paint is not overdiluted because it will loose many of its properties. Stir from time to time while painting.

HOW THE TOOL PAINTING MUST BE CHOSEN

Choose the tool that the manufacturer suggests and the same time better suits you. You can choose between roller, spray gun, airless spray gun or liquid electrostatic painting. Avoid painting thick coats because of the risk of wrinkles or sag, which at the same time will take much longer for the paint to dry, staying soft even though it has been surface dried. Make sure that the last coat of paint has dried before you apply the next one.

SAFETY MEASURES

Please read and follow all safety measures that are written on the labels of the tins.

HOW THE SPRAY GUN MUST BE USED

Spray gun is the most common tool for painting. While using a spray gun, be careful to keep the correct angle (90o) with the painting surface.

 

Follow a cross painting meaning that the second coat should be applied perpendicularly to the first one as shown at figure below.

Red = First coat
Blue = Second coat

 

You must keep the same distance from the surface (20-30 cm) during the spray gun motion. The pictures below show the correct use of spray gun.

For spray gun cleaning, first hold the gun nozzle closed with your fingers and press the trigger, then the paint will come back to the spray gun can. (WARNING not to be used with airless spray guns). After this, spray clear solvent until the gun cleans thoroughly. (Figure below)

 

TROUBLESHOOTING

Slow drying:

Low temperatures, high humidity, thick paint layers, insufficiently dried previous coat

Pinholes:

Painting in wet or oiled surface, oil in the air-supply line.

Sag:

Thick layers of paint, wrong spraying method, overdilution.

Wrinkles:

Thick layers of paint, forced surface drying (possibly in direct sunlight)

Bad leveling:

Insufficient dilution, extremely high or low temperature.

Bad gloss, matting after drying

Bad leveling, painting in rain, fog, snow or frost, painting on wrong primer, highly absorbent surface.

Soft paint:

Thick layers of paint, not through dried of previous coat, humidity, low temperature.

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