Should an Exterior Eggshell Finish Be Sanded Before Recoating?

Eggshell

• When you think of eggshell, you may picture a color of paint rather than a level of shine. The eggshell level of paint shine falls about halfway among the levels of shine or glossiness. Many paint colors are available in flat, satin, eggshell, semi-gloss, gloss and high-gloss varieties. Flat paints provide the lowest level of light reflection, and high-gloss paints supply a high amount of shine and gleam. Paints with shiny finishes tend to resist new coats of paint more than flat paints, although all paints cover best with a little sanding to remove the outer surface.

Adhesion

• Removing the outer surface of existing paint increases the bond of a new coat of paint. The surface of old paint may contain invisible debris such as grease, dust and fine particles that make it difficult for new paint to adhere properly. Sanding and applying a coat of primer can help to create a good bond between the old coat of eggshell paint and the new coat of fresh paint.

Sanding

• Removing only the outer layer of sheen is enough as long as the old eggshell paint is in good condition. Chipped and peeling paint requires more extensive sanding to eliminate loose edges. Avoid damaging the underlying siding or primer. Fine-grit sandpaper is generally sufficient to buff away the surface sheen of exterior eggshell paint. Hose down the surface after sanding, and let it dry prior to applying the new paint.

Precautions

• Paint applied prior to 1978 may contain lead. Contact your local building authority if you think that your exterior paint was applied prior to that year. Sanding lead-based paint may cause health problems.

  Using a primer prior to applying new paint is necessary, especially when the new paint is a much lighter color than the old eggshell paint.