Architectural Coating
Q #1: When do I need to apply a primer?
A #1: Generally, primer should be applied to any surface that has never been coated before. When recoating, a primer is needed when the surface is uneven in porosity, or when the previous coat has been removed. Primers are also needed when making a drastic color change, changing sheen levels and when painting over old surfaces where there may be oil based paint.
Q #2: What is oil paint and alkyd paint?
A #2: Oil paint uses a binder or resin that is derived from a vegetable oil such as linseed or soya bean. This resin is usually dissolved in a solvent such as mineral spirits. Alkyd paint is the most common kind of oil paint, and many oil paints are therefore normally referred to as alkyd paints. Alkyd is simply the name of the synthetic resin, usually containing a vegetable oil that is used as the binder.
Q #3: What are the benefits of oil or alkyd paint?
A #3: Oil or alkyd based paint provides resistance to mechanical damage from abuse and abrasion. Oil or alkyd paint is therefore well suited to areas of high wear. It has traditionally been used for such frequently cleaned areas as: Doors and trim, both inside and outside kitchens, bathrooms, and cabinets. The major advantages of oil or alkyd based paints: · Better penetration of the surface · Better adhesion · Wearability · Better flow and leveling · Smooth finish with few brush or roller marks.
Q #4: What should I use Oil based paints or Latex paints?
A #4: This choice is mostly a matter of personal preference, but it may help to make your choice based on the advantages each type of paint offers. Quality exterior latex paints provide better retention of gloss and colour than oil based paints, especially in sunny settings. They also resist chalking and long-term cracking and peeling better than oil-based products. Oil-based paints offer superior one-coat hiding and better adhesion to difficult chalky surfaces. If you must paint in conditions below 10°C, oil based paints offer better durability.
Q #5: What coating should I use for masonry?
A #5: Masonry substrates include concrete cement, stucco, etc. The most masonry coatings are latex based (provided under the trade name WT). Oil based coatings are not recommended for masonry surfaces because of the residual alcalinity in the masonry. Prior to coating masonry substrates a special treatment of the substrate using a bonding primer such as WT01 or STOP200 before application of a finish coat. Rough surfaces should be filled by STOP200 (acrylic & powder) to bridge cracks and pinholes and to provide the best waterproofing.
Q #6: What are the odor free decorative coating provided by Azmeh Co.?
A #6: Our water base odor free coatings that are perfect for living areas are provided under the trade name WT, namely WT01, WT03, WT05, WT07, WT08…. They are based on acrylic latex and formulated without harmful chemicals. They are suitable for interior or exterior surfaces. They have given excellent service on exterior masonry.
Q #7: What are decorative texture coatings and what are they recommended for?
A #7: Decorative texture coatings provided by Azmeh Co. namely WT11 are a good answer to problem walls and ceilings; it is thick bodied enough to seal most minor imperfections (large holes and cracks most be filled by WT03 or STOP200) and leave a decorative finish. WT11 come in two basic consistencies (Fine "Andalusite, and Coarse "Marble") with different textures. Depending upon the desired visual effect and the specific coarseness of the paint, brushes, rollers, putty knives, and other applicators can be used to create a variety of patterns or designs. After these finishes have been applied and allowed to dry, the surfaces can be topcoated by a colored finish. WT11 may also be tinted prior to application.
Q #8: Can water-based paint be applied over oil-based paint and is the reverse possible?
A #8: In the past it was always recommended that the same type of coating be used, however that is not always true today. Providing proper surface preparation, for exterior use you can apply quality latex coating over oil-based due to their excellent adhesion properties, but not the reverse. But if a surface has more than three or four coats of oil-based coating on it, you may want to apply an oil-based topcoat. For interior use, generally you can use one over the other. We recommend, when applying water base paint over oil base paint, that you thoroughly clean the surface and lightly sand any glossy areas. Then prime the entire surface with a WT01 (Acrylic primer/sealer). Let the primer dry overnight and then topcoat the surface with WT07/WT08. These acrylic latex products are able to expand and contract without becoming brittle and are less prone to fading than oil based products.
Q #9: How to differentiate if the previous coated surface in decorative coating is oil based or latex based?
A #9: If the paint is at least several years old and is peeling, take a piece of it and bend it. If it cracks, it is most likely oil based or alkyd paint. If it seems flexible, it is probably latex. (However, highly pigmented economy latex paints can tend to crack when flexed this way). If it is a combination of one type applied over the other, then the oil-based portion is more likely to crack, while the latex part would be more flexible. Another test would be to soak the piece of peeling paint in some acetone or fingernail polish remover. If it dissolves or significantly softens, then the peeled paint is likely to be latex.
Q #10: What are the major causes of uneven gloss on the paint film?
A #10: Three major causes are responsible for uneven gloss: Inadequate sealing of a porous substrate. The thickness of the paint film is not constant, the gloss will raise with increased film thickness. The effect is increased in deep colors. Deposits of moisture on the coated surface during drying flatten the paint film (in oil based paint).
Q #11: Can I paint over ceramic tile?
A #11: Yes it is possible but first you should clean the surface using detergent and hot water. Next, lightly sand the tiles with fine (220 grit) sandpaper. Wipe the surface with a damp rag. Then apply epoxy primer EPX02 Gray. Allow it to dry over night then apply WT07 or WT08. Apply a second coat if necessary.
Q #12: I have stress cracks in my interior walls and bathroom ceiling. How are stress cracks repaired?
A #12: The cracks can be repaired by first scraping them out to widen them to 0.5-1 cm. Clean out the dust with a vacuum, compressed air, or by brush. Fill with WT25 (ready mixed type) or STOP200 (two-component, acrylic and powder) and let dry over night. Then sand it and make a second application to fill eventual small cracks appearing on the surface during drying. Dry several hours, and sand smooth; use fine sandpaper (180 or 220 grit) for the final sanding. Remove sanding residue from the surface. The substrate is then ready for priming and coating.
Q #13: What is Latex paint and what are the advantages?
A #13: Latex paints are referred to as water-thinned or water-based paints. Their major components are water, pigment and an emulsion resin (latex). In addition to being thinnable with water, latex paints feature: · Less odor · Water cleanup · Non-flammable · Fast drying · Ease of touch up · Ease of application · good gloss · Less fading on exteriors · No yellowing on interiors · Less likely to crack or peel · Damp surfaces are not detrimental during application, the water can subsequently evaporate.
