Painting Failure Continued: Painting in Vancouver

Vancouver’s Best Painters

When a manufacturer makes a mistake with a coating batch that causes it to fall outside specified tolerance ranges, the coating is either discarded or remanufactured to bring it within tolerance. As one might imagine, it is expensive to throw away a batch of 50 to 1,000 gallons or more of coating material. Accordingly, coating manufacturers may do extensive reworking of a batch before deciding to discard it. These “reworked” batches may have more application or performance problems that a coating batch that initially is manufactured properly.

SURFACE PREPARATION

The preparation of a substrate prior to painting is probably the most tedious, expensive, and time-consuming portion of any paint job. It is also the most critical in preventing failures. Prior to painting, the surface must be dry. All oil, grease, dirt, mildew, and other residues must be removed. Surface irregularities must be eliminated or minimized, and holes must be filled. Non visible chemical contaminants as well as aged, brittle, or loose coating material must also be removed. Finally, the surface should have a roughness suitable for good adhesion. If any of these surface preparation conditions is not adequately met, the possibility for coating failure becomes high, particularly if the exposure environment is relatively severe.

When there is insufficient surface preparation, paint may fail because:

•Dirt, debris, oil, grease, mildew, moisture, or old, deteriorated paint prevent the coating

from bonding.

Contaminants such as salt residue draw moisture through the coating to the surface and cause blistering.

            The surface is too smooth for paint to adhere.

            The surface is not sound.

       Cracks or holes, such as bug holes in concrete, cause openings in paint film.

COATING APPLICATION

Most coating materials are applied by brush, roller, or spray equipment. Because successful application depends upon the skill of the craftsperson, failure can occur because of application error. For instance, during spray application, the spray gun should be moved at the appropriate speed, be held perpendicular to the surface being painted, and not be held either too close or too far away. In roller operations, the proper roller nap should be used, and care should be taken not to roll out the paint too much. When brushing, the proper size and shape brush and suitable bristle should be used. It is also important to use the proper technique for dipping the brush and spreading the paint onto the surface.

Vancouver’s Best Painters.

www.vancouversbestpainters.com