Valspar Bonding Primer-Sealer: Basics and Review

Rolling Paint Primer on a Wall

art at its best / Getty Images

When you need to cover the surface, block minimal stains, and provide protection, you can use ordinary acrylic-latex paint. But when you have issues such as stains, mold residue, old paint, or discoloration, you probably need the extra services of a bonding primer-sealer—one like Valspar Stainblocking Bonding Primer-Sealer.

 Purpose  Primer for helping paint stick to surfaces with issues
 Type  Acrylic-latex
 Coverage  200 to 400 gallons
 Surfaces  Wood, drywall, melamine, tile, or laminate, and more
 Base  Water

What This Valspar Product Is

Valspar Stainblocking Bonding Primer-Sealer is a one-step primer and sealer coat designed to work on problematic surfaces, both porous and glossy.

Covering between 200 and 400 square feet per gallon, this primer is exceedingly thick, making it difficult to handle, so use sparingly.

But the product's thickness is inescapable since most bonding primers rely on thick viscosity to help paint adhere not just to ordinary surfaces like drywall but to problem surfaces like metal and plastic. Bonding primers are also the way to begin if you intend to paint melamine, tile, or laminate.

In most cases with bonding primers, the per-gallon cost is more than the cost of comparably sized interior or exterior acrylic-latex paint. However, this cost usually evens out in the end since fewer coats of bonding primers are required. In many cases, only one coat is needed in order to help subsequent layers of paint adhere.

  • Valspar Stainblocking Bonding Primer-Sealer is thick and will handle almost any kind of material.

  • Valspar Stainblocking Bonding Primer-Sealer sands down smooth.

  • Being water-soluble, the product easily cleans up or thins with water.

  • This product is thick enough to block stains and knot holes in wood.

  • Low odor and low VOC, this product is not noxious to work with.

  • The product adheres to and seals glossy surfaces with no need for sanding.

  • Compared to other bonding primers, this product is less expensive than most.

  • Because of its thick viscosity, the product can be difficult to spread, roll, and brush.

  • This product is not widely available and can be difficult to obtain.

How to Use Bonding-Primer Sealers

If you are accustomed only to working with acrylic-latex paint, Valspar Bonding Primer-Sealer and other brands of primer-sealers operate generally the same way. There are a few exceptions, though. Bonding primer-sealers are very thick, which makes them difficult to pour, roll, and brush.

Valspar Stainblocking  Bonding Primer can be used with an airless sprayer at 2,000 PSI with a standard 0.015–inch to 0.021-inch size tip. Use only a high-quality, sturdy roller and a medium-nap (3/8-inch to 1/2-inch) roller cover. When using a brush, opt for a polyester brush, rather than horse hair. 

  1. Even though bonding primer-sealers can cover limited amounts of dust and debris, it is still best to clean the surface as thoroughly as possible and then let it dry. Especially dusty and chalky surfaces should be cleaned, as well as those that are greasy, oily, and waxy. Remove all peeling paint.
  2. Stir the product with a drill and mixer instead of with a wooden stirring stick. This is necessary to pull up the solids from the bottom of the can.
  3. Since this product can stick to glossy surfaces, it is not absolutely necessary to sand them. However, if you are able, sanding will always help a bonding coat adhere better.
  4. Cover nail holes with wood putty and caulk all cracks and joints.
  5. Clean all mildew with a solution of one part liquid chlorine bleach to three parts of water, then rinse clean.
  6. Let the surface completely dry. If the surface is bare wood, it may take at least two full days for the wood to fully dry.
  7. Line the metal roller tray, then pour the product in the lined roller tray. Pour in only enough to cover the lower reservoir.
  8. Lightly dab the roller cover in the product. If using a brush, load the brush lightly on the tips of the bristles.
  9. Apply in one coat. Work briskly as the product dries fast. Keep moving the brush or roller in the same direction and try to work off of a wet edge.
  10. To clean, run warm, soapy water across brushes, rollers, and other equipment. Use a paint comb to comb out the water from brushes, shake dry, then hang for further drying.
  11. Because bonding primer-sealer dries especially thick and hard, it will gum up the paint can near the lid. So be especially sure to clean up the can's grooved top before tightly replacing the lid by hammering lightly.

Review of Valspar Stainblocking Bonding Primer-Sealer

If you are tired of priming and re-priming, then a bonding primer may be what you need. When you have a difficult surface such as knotty or tannin-releasing wood, slick glass or metal, or even weathered paint on wood, you need a bonding primer.

This primer bonds especially well to highly porous and otherwise poor surfaces because, physically, it lays on and stays on like a thick plastic blanket. This is a one-coat primer you can apply to almost anything prior to painting. After the product has completely dried, it is sandable down to a smooth surface suitable for painting.

This primer can be used on brick, natural stone, veneer stone, new and old drywall, plaster, bare wood, painted wood, wood paneling, PVC, all types of metal including aluminum, ceramic tile, porcelain tile, glass, and some weathered paint.

Though this product can cover up many issues on a surface, all mildew must first be completely removed.

Keep in mind that you pay the price for this by having to deal with its very thick consistency. But this is typical for any of these one-step, thick primers, Masterchem's KILZ being Valspar's most prominent competitor.

Bonding primer is often touted as the miracle subsurface for porous surfaces like weathered wood or masonry because its thickness bridges cellular spaces. But for those who need to paint slick items like laminate, melamine cabinets, glass tile, ceramic or porcelain tile, a bonding primer is the only way to begin.