The core of the painting industry has always been alkyd primer, often called oil base primer. With a long history spanning decades, many varieties have been developed. All standard oil based primers are compatible with oil base paint and acrylic paint, making it a perfect choice for many painting projects.
Alkyd primer offers great advantages over other types of primer.
- High adherence to a wide variety of surfaces. These include unpainted or painted wood, masonite, MDF, steel, iron, galvanized metal, chalky paint and graffiti.
- Some oil base primers dry very fast allowing the application of the finish paint within an hour.
- Compatible with many types of paint, including industrial finishes.
Types of Oil Base Primers
Universal Primer/Sealers – All purpose alkyd primer is formulated for a variety of painted or unpainted surfaces. Such as painted and unpainted wood trim and siding, masonite siding and trim, glossy paint, doors, MDF, chalky paint, etc.
Oil base primer is excellent at sealing tannin bleed from redwood, cedar and other high extractive wood types. Dry times vary from 1 hour to 24 hours depending on product chosen.
Stain Blocking Primer – An economical paint primer providing fast drying and universal application over most interior or exterior surfaces. Will seal many stains including water stains, nicotine, crayon, marker, graffiti, gloss paint, wood tannins and sap from redwood or cedar, etc.
Effective at sealing many kinds of wallpaper. Might not seal oily stains and graffiti that are soluble in mineral spirits. Many products are easy to sand making them suitable for interior wood trim and doors prior to applying enamel finishes.
Wood Primer – Oil based wood primer is ideal for unpainted wood surfaces, both interior and exterior. Typically dries slowly, which allows it to soak into the wood pores and bind with the fibers.
Highly porous woods may require 2 coats before application of the finish. Dry time can be 24 hours or more depending on temperature and humidity. To decrease this time Japan Dryer can be added sparingly to the oil base primer.
Enamel Undercoat – The best choice for interior woodwork, such as base, casing, and doors. Dries very quickly, typically 1 hour and sands easily to create a smooth surface for either Alkyd or Acrylic enamels. 2 coats will be necessary before sanding.
Metal Primer – Many universal metal primers offer quick drying, 1 hour to topcoat, and good adhesion to iron and steel. Can be brushed, rolled or sprayed and top coated with either a Alkyd, oil base, or Acrylic, Latex, finish.
Galvanized Metal Primer – Galvanized metal, gutters and flashing, require special care before painting, this includes the use of a alkyd primer designed for galvanized surfaces. This oil base primer etches the metal surface providing maximum adhesion for the finish.
Common Rules for Choosing an Alkyd Primer
- Universal primers-sealers are an excellent choice for most surfaces. But, choosing a product designed for a specific surface is better. No compromises are made with surface specific products.
- Wood can have tannins and sap that can bleed through the primer and finish coats. Use a stain blocking primer to stop bleed through.
- An enamel undercoater will provide smooth results on painted interior wood trim and doors.
- Alkyd, oil base primer, will work very well for minor stains but a pigmented shellac is a better choice for heavily stained interior areas.
This type of paint primer is reduced with mineral spirits and has a strong solvent smell. Use adequate ventilation when used indoors. Application methods include brushing, using a natural bristle paint brush, rolled or sprayed, with either an airless paint sprayer or an HVLP paint sprayer.
