STAIN BLOCKERS: OIL-BASED VS. WATER

Like standard primers, stain-blocking primers provide good adhesion and help hide existing colors and repairs. But stain blockers promise something more: They seal in stains better than standard primers or paint.

- JASON INGOLFSLAND

Some types of stains dissolve when a fresh coat of paint is applied and bleed right through to the surface of the new paint. These stains won’t completely disappear no matter how many coats you apply— they just keep bleeding through. So you have to seal them before you paint.

The conventional wisdom is that water-based stain blockers don’t work as well as oil-based or shellac-based products. To test that theory, I bought three oil-based primers, three water-based primers and one shellac-based primer, then set out to test them all.

The homeLAB test