If you’re looking to do some painting around your home, choosing the right primer is crucial for getting great results. Two popular primer options on the market are Sherwin Williams Pro Block primer and Kilz original primer.
But which one is better? Here we’ll compare the pros, cons, uses, and key differences between Sherwin Williams Pro Block and Kilz primer to help you decide which is best for your next painting project.
A Brief Comparison Table
| Feature | Sherwin Williams Pro Block | Kilz Original |
| Primer Type | Oil-based | Oil-based |
| VOC Content | 350 g/L | 350 g/L |
| Finish | Flat, matte | Flat, matte |
| Application Temperature | 35°F – 90°F | 40°F – 90°F |
| Dry Time | 1 hour recoat | 1 hour recoat |
| Coverage | 300-400 sq ft/gal | 300-400 sq ft/gal |
| Stain Blocking | Maximum stain blocking | Heavy-duty stain blocking |
| Sheen Holdout | Excellent on glossy surfaces without deglossing | Requires prep on glossy surfaces |
| Scrub Resistance | Very good | Not specified |
| Mold/Mildew Resistance | Not specified | Yes |
| Tinting Ability | No | Yes |
Overview of Sherwin Williams Pro Block Primer
Sherwin Williams Pro Block primer is a heavy-duty, oil-based primer that provides maximum stain blocking and sealing properties. It adheres well to a variety of surfaces including wood, drywall, plaster, masonry, aluminum, galvanized metal, PVC, and more.
Some of the key features and benefits of Sherwin Williams Pro Block primer include:
- Excellent stain blocking – The Pro Block formula is designed to lock in stains from water, smoke, ink, pencil, grease, etc. so they don’t bleed through the finish coat of paint. This makes it ideal for covering up stains on interior walls, ceilings, doors, trim, and cabinets.
- Seals surfaces – It seals porous surfaces to provide a smooth, uniform surface for topcoat paints. This helps prevent topcoat paints from soaking in unevenly.
- Sticks to glossy surfaces – Unlike some water-based primers, Pro Block primer adheres well to slick, glossy surfaces like tile and laminate without sanding or deglossing first. This saves an extra preparation step.
- High hiding power – It covers existing colors well, even bold colors like reds, blues, and purples in just one coat in most cases. This prevents having to apply multiple coats of primer to hide old colors.
- Fast drying – Pro Block dries quickly, normally within an hour, so you can recoat it faster.
- Low odor – It has minimal odor compared to many oil-based primers.
- Good flow and leveling – It applies smoothly and levels out nicely to create an even surface.
- Interior/exterior use – Pro Block can be used for both interior and exterior painting jobs.
- VOC compliant – This primer contains fewer VOCs than traditional oil-based primers, making it compliant with VOC regulations.
Sherwin Williams recommends Pro Block primer for interior surfaces like drywall, plaster, wood doors, trim, cabinets, furniture, stucco, wallpaper, aluminum, galvanized metal, and PVC.
For exterior surfaces, they recommend it for wood, hardboard, aluminum, galvanized metal, and fiberglass. It can be used as a spot primer or as a full surface primer coat.
Overview of Kilz Original Primer
Kilz Original is a fast drying, heavy-duty, oil-based primer, sealer, and stain blocker. It works on a variety of surfaces, including wood, drywall, plaster, paneling, wallpaper, masonry, brick, painted metal, and properly prepared glossy surfaces.
Some of the key qualities of Kilz Original primer include:
- Blocks stains – It seals in stains from water, smoke, tannins, ink, pencil, grease, and more to prevent them from bleeding into paint. This makes it a great primer choice for covering nicotine stains and smoke odors.
- Seals porous surfaces – Kilz Original seals and fills porous surfaces, creating a smooth, even base for paint. It prevents uneven absorption of paint.
- Adheres to glossy surfaces – Unlike some water-based primers, Kilz Original sticks tightly to slick, glossy surfaces like ceramic tile and laminate after proper prep and cleaning.
- High hiding power – It covers existing colors thoroughly in one coat in most cases, including bold colors like reds and blues.
- Quick drying – Kilz Original dries fast, allowing you to recoat within 1 hour in most cases.
- Low odor – It has less odor than traditional oil-based primers.
- Good surface penetration – The primer penetrates and seals surfaces well for a tight adhesive bond.
- Can be tinted – Kilz Original can be tinted to match the color of your finish paint, making your topcoat more opaque.
Kilz recommends their original primer for interior and exterior surfaces including wood, drywall, plaster, paneling, wallpaper, masonry, brick, painted metal, galvanized metal, PVC, vinyl, aluminum siding, and properly prepared glossy surfaces. It can be used as a full primer or spot primer.
Now that we’ve overviewed the general qualities and uses of these two popular primers, let’s compare them head-to-head.
Sherwin Williams And Kilz Primer Comparison
While Sherwin Williams Pro Block and Kilz Original share several similar characteristics, there are some differences between the two primers to consider:
Primer Type
- Sherwin Williams Pro Block – oil-based primer
- Kilz Original – oil-based primer
VOC Content
- Pro Block – 350 g/L
- Kilz Original – 350 g/L
Both primers are similar in VOC content and meet VOC regulations.
Finish
- Pro Block – flat, matte finish
- Kilz Original – flat, matte finish
Both leave a flat, non-reflective finish ideal for priming.
Application Temperature
- Pro Block – 35°F – 90°F
- Kilz Original – 40°F – 90°F
Pro Block can be applied in slightly colder temps.
Dry Time
- Pro Block – 1 hour dry to recoat
- Kilz Original – 1 hour dry to recoat
Both primers dry quickly within 1 hour before applying paint.
Coverage
- Pro Block – 300-400 sq ft/gal
- Kilz Original – 300-400 sq ft/gal
The coverage rate is estimated to be similar for both primers.
Surfaces
- Pro Block – Wood, drywall, plaster, aluminum, galvanized metal, PVC, masonry
- Kilz Original – Wood, drywall, plaster, paneling, brick, masonry, painted metal, PVC
Both work well on common interior and exterior building surfaces. Kilz calls out efficacy on paneling and painted metal while Pro Block highlights aluminum, galvanized metal, and masonry.
Stain Blocking
Both primers excel at sealing stains, but Pro Block offers max stain blocking, while Kilz Original is marketed as a heavy-duty stain blocker. Pro Block specifies locking in water, smoke, ink, grease, pencil, and crayon stains where Kilz calls out nicotine, water, tannin, smoke, ink, grease, and pencil.
Sheen Holdout
Pro Block promotes adhesion to glossy surfaces without prep whereas Kilz Original requires deglossing and prep on shiny surfaces.
Scrub Resistance
Pro Block claims excellent scrub resistance that allows for cleaning without damaging the primer coat. Kilz does not specifically promote washability or scrub resistance.
Mold/Mildew Resistance
Kilz Original Primer is mold and mildew resistant to help prevent future mold growth. This feature is not specified for Pro Block.
Tinting
Kilz Original primer can be tinted close to your finish paint color. Pro Block does not offer tinting ability.
So in summary, the main differences are:
- Pro Block offers maximum stain blocking, higher sheen holdout without deglossing, better scrub resistance, and ability to apply at slightly colder temperatures.
- Kilz Original can be tinted to your finish paint color, and it has added mildew resistance.
Overall, the performance of these two oil-based primers is comparable across most general uses with some minor advantages for each primer.
When To Use Sherwin Williams Pro Block Primer?
Since Pro Block offers maximum stain blocking, it’s a great choice when you have heavy stains to cover such as:
- Water stains
- Smoke stains
- Grease stains
- Marker/ink stains
- Crayon stains
It also provides excellent sealing for surfaces where you don’t want the finish paint to be absorbed unevenly, such as:
- Drywall
- Ceilings
- Plaster
- Wood doors and trim
- Cabinets
- Furniture
Pro Block’s ability to adhere to glossy surfaces without sanding also makes it ideal for priming:
- Ceramic tile
- Laminate
- Formica
- Vinyl flooring
- Aluminum siding
- Galvanized metal
- PVC pipes
Finally, when you need long-lasting protection under paint in high traffic areas that will be cleaned frequently, Pro Block’s scrub resistant finish makes it a smart choice for priming walls, trim, cabinets, doors, and furniture in:
- Kitchens
- Bathrooms
- Hallways
- Family rooms
- Offices
- Commercial spaces
So in summary, prime with Sherwin Williams Pro Block for heavy stain blocking, sealing porous or glossy surfaces, and when you need increased scrub resistance for durability.
When To Use Kilz Original Primer
Since Kilz Original Primer can block medium to heavy stains, prevent mold and mildew growth, and gets tinted, it’s ideal for:
- Covering nicotine stains and smoke odors
- Priming in mold-prone areas like bathrooms and basements
- Tinting so your topcoat is less likely to need multiple coats
The fast drying time and stain blocking power also make Kilz a good choice when time is tight and you need to prime over stains fast, such as when:
- Staining and painting furniture
- Priming rental properties between tenants
- Flipping houses
Kilz Original works well as an all-purpose primer suitable for most rooms and situations when you don’t have severe stains to block. It provides a uniform sealed surface for paint adhesion.
It’s also easy for DIYers to find and purchase Kilz primer at home improvement stores, unlike Pro Block which is sold through Sherwin Williams stores.
Consider Kilz Original primer for general interior and exterior painting needs, quick stain blocking between tenants or projects, and areas prone to mold growth.
Frequently Asked Questions (FAQ)
Pro Block primer is designed for maximum stain blocking, sealing porous surfaces evenly, and adhering to glossy surfaces without prep. It’s ideal for covering heavy stains, priming drywall, plaster, wood, laminate, tile, aluminum siding, galvanized metal, and where you need added scrub resistance.
Sherwin Williams Pro Block primer dries within 1 hour typically, allowing you to recoat fairly quickly. Full curing takes longer, around 7 days.
Yes, Sherwin Williams PVA primer can be used on interior bare or painted wood. It dries fast, sands easily, and offers good adhesion and sealing. For exterior wood, an oil-based primer like Pro Block is a better choice.
Yes, Kilz Original oil-based primer acts as both paint and primer in one. It blocks stains, adheres well, and its sealing action prepares surfaces similarly to a dedicated primer. Using Kilz can eliminate the need for separate primer and paint coats.
Closing Remarks
When choosing between Sherwin Williams Pro Block and Kilz Original primer, consider Pro Block for heavy stains and maximum sealing and scrub resistance. Opt for Kilz when you need fast stain blocking between coats, mold resistance, or the ability to tint primer.
Both offer quality oil-based priming and long-lasting results. Carefully prep surfaces and follow application instructions for best results. Take time to prime properly, and you’ll save time and get better looking paint outcomes.