Rabu, 01 Juli 2009

Mud Cracking

Deep, irregular cracks resembling dried mud in dry paint film.


Possible Cause :
  • Paint is applied too thickly, usually over a porous surface.
  • Paint is applied too thickly, to improve in herent poor hiding ( coverage ) of a lower quality paint.
  • Paints is allowed to build up in corners upon application
Solution :
  • Remove coating by scraping and sanding.
  • Prime and repaint, using a top quality latex paint.
  • Mud-cracking areas can also be repaired by sanding the surface smooth before repainting with a top quality latex paint, this type of paint is likely to prevent recurrence of mud cracking, because it is relatively more flexible than alkyd paint, oil based paint and ordinary latex paint.
  • Quality paints have a higher solids content, which reduces the tendency to mud crack. They also have very good application and hiding properties, which minimize the tendency to apply too thick a coat of paint.

Picture Framing

An effect of non-uniform color that appear when a wall is painted with a roller, but is brushed at the corners. The brushed areas generally appear darker, resembling the " frame " of a " picture ". Also, sprayed areas may be darker than neighboring sections that are brushed or rolled. Picture framing can also refer to sheen effects.

Possible Cause :
  • Usually a hidding (coverage) effect. Brushing will generally result in lower spread rates than rolling, producing a thicker film and more hiding.
  • Adding colorant to a non-tintable paint or using the wrong type or level of colorant.
Solution :
  • Make sure that spread rates with brushes and rollers are similiar.
  • Don't cut in the entire room before roller coating.
  • Work in smaller sections of the room to maintain a " wet edge. "
  • With tinted paint, be sure the correct colorant-base combinations are used.
  • Factory colors, as well as in-store tints, should be thoroughly shaken at time of sale.

Senin, 29 Juni 2009

Mildew

Black, gray or brown spots or areas on the surface of paint or caulk.

Possible Cause :
  • Forms most often on areas that tend to be damp, or receive little or no direct sunlight (e.g., bathroom, kitchens, and laundry rooms).
  • Use of an alkyd or oil based paint, or lower quality latex paint.
  • Failure to prime a bare wood surface before applying the paint.
  • Painting over a substrate or coating on which mildew has not been removed.
Solution :
  • Test for mildew by applying a few drops of household bleach to the area, if it is bleached away, the colorant is probably mildew
  • Remove all mildew from the surface by scrubbing with diluted household bleach solution (one part bleach, three parts water), while wearing rubber gloves and eye protection.
  • Rinse thoroughly
  • To protect againts mildew, use a top quality latex paint, and clean when necessary with bleach / detergent solution.
  • Consider installing an exhaust fan in high moisture areas.

Lapping

Appearance of a denser color or increased gloss where wet and dry layers overlap during paint application.

Possible Cause :
  • Failure to maintain a " wet edge " when painting.
  • Use of low solids " economy " paint.
Solution :
  • Maintain an wet edge when painting by applying paint toward the unpainted area and then back into the just-painted surface. This technique (brushing or rolling from " wet to dry " rather than vice versa) will produce a smooth, uniform appearance. It is also wise to work in manageable-size area ; plan for interruptions at natural break, such as a window, door or corner.
  • Using a top quality acrylic latex paint makes it easier to avoid lapping problems because higher solids (pigments and binder) content makes lapped areas less noticeable.
  • If substrate is very porous, it may need a primer / sealer to prevent paint from drying too quickly and reducing wet edge time.
  • Alkyd paints generally have superior wet edge properties.

Cracking / Flaking

The splitting of a dry paint film through at least one coat as a result of aging, which ultimately will lead to complete failure of the paint. In its early stages, the problem appears as hairline crack, in its later stages, flaking occurs.

Possible Cause :
  • Use of lower quality paint that has inadequate adhesion and flexibility.
  • Overthinning or overspreading the paint.
  • Inadequate surface preparation, or applying the paint to bare wood without first applying a primer
  • Excessive hardening and embrittlement of alkyd paint as the paint job ages.
Solution :
  • Remove loose and flaking paint with a scraper or wire brush, sanding the surface and feathering the edges.
  • If the flaking occurs in multiple layers of paint, use of a filler may be be nacessary.
  • Prime bare wood areas before repainting.
  • Use of a top quality primer and top coat should prevent a recurrence of the problem.

Foaming / Cratering

Formation of bublles (foaming) and resulting small, round concave depressions (cratering) when break in a paint film, during paint application and drying

Possible Cause :
  • Shaking a partially filled can of paint.
  • Use of low quality paint or very old lated paint.
  • Applying (especially rolling) paint too rapidly.
  • Use of a roller cover with wrong nap lenght
  • Excessive rolling or brush of the paint.
  • Applying a gloss or semigloss of the paint over a porous surface.
Solution :
  • All paint will foam to some degree during application, however, higher quality paint are formulated so the bublles break while the paint is still wet, allowing for good flow and appearance.
  • Avoid excessive rolling or brushhing of the paint or using paint that is more than a year old.
  • Apply gloss and semigloss paint with a short nap roller, and apply an appropriante sealer or primer before using such paint over a porous surface.
  • Problem areas should be sanded before repainting.

Minggu, 28 Juni 2009

Caulk Failures

Loss of caulk's initial adhension and flexibility, causing it to crack and / or pull away from the surfaces to which it is applied.

Possible Cause :
  • Use of ower quality caulk.
  • Use of wrobng type of caulk for particular application (e.g., using latex or vinyl caulk in area where there is prolonged contact with water or considerable movement of the caulked surfaces).
Solusion :
  • Use a top quality water based all acrylic or siliconized acrylic caulk if prolonged contact with water is not anticipated.
  • These caulks are flexible enaough toadapt ti minor fluctuations in the substrate, stretching in gaps that widen slightly over time.
  • They also adhere to a wide range of interior building material, including wood, ceramic tile, concrete, glass, plaster, bare aluminum, brick and plastic - even in area where moisture is present.
Note : Silicon caulk should not be painted