Exterior Paint Solution Center

Tannin Staining

Brownish or tan discoloration appearing on the paint surface due to wood tannins migrating from the substrate through the paint film. Tannin staining typically occurs with “staining wood,” such as redwood, cedar and mahogany, or over painted knots in certain other wood species.


	Cause:
Failure to adequately prime and seal the surface before applying the paint. Use of a primer that is not designed to be stain-resistant. Excess moisture escaping through exterior walls that carry the stain through the paint surface.
		Solution:
Moisture will act as a carrier bringing the tannins to the surface. Correct any possible sources of excess moisture (see Efflorescence and Mottling). After thoroughly cleaning the surface, apply a high quality stain-resistant exterior oil-based or latex primer. Oil-based stain-resistant primers are better suited for use on severely stained boards. In extreme cases, a second coat of primer can be applied after the first has dried thoroughly. Finish with a top quality latex paint.

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Vinyl Siding Warp

Warping of buckling of vinyl siding panels that have been repainted.


	Cause:
The vinyl siding was repainted with a darker color paint than the original color. Dark paint tends to absorb more heat from the sun, transferring it to the substrate. When vinyl siding expands dramatically, it is not able to contract to its original dimensions.
		Solution:
Paint vinyl siding with a color shade no darker than the original color. Whites, off-whites, pastels, and other very light colors are excellent choices. A high quality latex paint is the best type of paint to use on vinyl siding, because the superior flexibility of the paint film enables it to withstand the stress of expansion and contraction cycles caused by outdoor temperature changes. Siding that has warped or buckled should be assessed by a siding or home repair contractor to determine the best remedy. The siding may have to be replaced.

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Wax Bleed

Discoloration of the paint film caused by waxy components found in reconstituted wood products used to make hardboard siding. When the substrate is painted, these wax components bleed through the paint. They will even bleed through ordinary primers, possibly causing dirt pickup, mildew, and/or poor paint adhesion (see Dirt Pickup and Mildew).

	Cause:
Failure to apply a proper primer to hard board before applying the topcoat. Allowing hardboard siding to weather before being painted.
		Solution:
To treat or prevent, apply a quality exterior latex primer; follow with a coat of high quality exterior acrylic latex paint. The American Hardboard Association recommends two coats of high quality exterior latex paint. Some hardboard grades have adequate factory primer and need only a quality paint applied. Low quality, highly pigmented flat finish paints are more prone to wax bleed than are higher gloss quality paints.

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Wrinkling

A rough, crinkled paint surface occurring when paint forms a “skin”.

	Cause:
Paint applied too thick (more likely when using alkyd or oil-based paints). Painting a hot surface or in direct sunlight. Exposure of uncured paint to rain, dew, fog, or high humidity levels. Applying topcoat of paint to insufficiently dried first coat. Painting over contaminated surface (e.g., dirt or wax).
		Solution:
Scrape or sand substrate to remove wrinkled coating. Repaint, applying an even coat of high quality latex exterior paint. Make sure the first coat or primer is dry before applying the topcoat. Apply the paint at the manufacturers recommended spread rate, two coats at the recommended spread rate are better than one thick coat. Avoid painting under adverse weather conditions, such as in direct sunlight. When painting during cool or damp weather, allow extra time for the paint to dry completely.

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