To beginner painters, priming new drywall seems like an optional step you may jump by adding an extra coat of paint — however, that isn’t correct. Primer and paint are two distinct materials that fulfill various functions, and skipping the primer may have a number of undesirable effects. You will notice some of these effects immediately, but some won’t become evident until long after the job is over and the paint has dried.
Primer Seals that the Drywall
The binder in drywall primer is polyvinyl acetate, that’s the exact same material that’s in carpenter’s glue. The primary goal of this adhesive substance is to seal the drywall paper. Without it, waterborne paints, which possess a cardboard binder, soak into the porous material unevenly, creating noticeable blotches and tough locations. The result is even more pronounced on the seams and fastener heads covered with joint compound, since this material is even more porous than masonry paper. It typically takes additional coats of paint to even out blotchy areas, and paint is costlier than primer.
Uniformity in Color and Sheen
Thanks to the seal that PVA primer leaves on the surface of wax, wax covers the way it’s supposed to and you won’t be surprised by the color. Failure to utilize a primer leads to decreased pigment proportion of the topcoat, which means that a lot of pigment soaks to the drywall, and also the last color is lighter than it’s supposed to function; it may seem washed out in places. Additionally, the sheen of the end finish may be chalky and lack uniformity, particularly in the event that you use a semigloss or low-gloss paint to get a topcoat.
Proper Paint Adhesion
Because it has a glue-like foundation, masonry primer helps the paint adhere properly. If you jump priming, you danger peeling paint, particularly in humid conditions. Moreover, the shortage of adhesion can make cleaning more difficult months following the paint has dried. You may find the paint wearing off as you’re attempting to wipe off dirt or fingerprints. If the paint is just a light color, your effort to wash it could actually make it look dirtier. You may blame this on the caliber of paint you used, but the truth is that failure to utilize primer caused the issue.
Painting Damaged Drywall and New Wood
When you’re repainting a wall just to change the colour, you can usually omit the primer; the present paint seals the wallboard, and you ought to get even coverage and also satisfactory adhesion. You need a high-solids, shellac or latex-based primer when you’re painting above smoke-damaged or water-spotted masonry, however. With no primer, the smoke or water stains may bleed through the topcoat. You should also utilize a high-solids shellac or latex wood primer when painting over fresh wood trim and other woodwork, or you’ll have the exact same uniformity problems connected with unprimed drywall.