Zinc primers have applications for both commercial and individual use. We’ll start by discussing the best zinc primers in both paint cans and spray cans. In general, spray cans handle small, one-off projects, while paint cans are for larger surface area projects.
Next, we’ll take a look at the difference between zinc chromate and zinc phosphate primers. Finally, we’ll discuss the big takeaways for facility owners, fleet owners, and other commercial applicators.
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Best Zinc Primers in Paint Cans
- Best quality: ZRC 10002
- Best price: Rust-Oleum zinc chromate primer
- Best cold galvanizing coat: Crown 7007G
Best Zinc Primers in Spray Cans
- Most versatile: Krylon Rust Tough zinc rich primer
- Best cold galvanizing coat: Dupli-Color
- Best for buying in bulk: Valspar zinc antirust primer
Table of Contents
Zinc primers in spray cans
Krylon offers one of the most versatile spray cans on the market, a zinc primer that can be applied to metal without primer or intense surface preparation. It dries in 30 minutes or less, which allows for quick paint projects.
- Price: $12 for 12 fluid ounces
- Can be used on metal, fiberglass, masonry, wood and plastics
- Excellent adhesion
- Quick dry times
Dupli-Color offers a cold galvanizing spray for heavy duty projects. Cold galvanizing spray cans offer superior protection to zinc primers with less zinc.
- Prices: $11.99 per 12 ounce spray can
- 30 minute dry times
- 4.5 stars on 21 Amazon reviews
You can find Dupli-Color’s cold galvanizing spray paint in one packs and 6 packs:
Valspar’s zinc anti rust spray paint is the most cost effective option available on Amazon. There’s little product information on Valspar’s zinc primer, but it does offer 90% zinc content. However, it’s only offered in bulk option
- Price: $6 per 12 ounce spray can
- 90% zinc content
Zinc primers in paint cans
Zinc-rich Primers typically come in spray cans or paint cans. For bigger projects, such as priming a boat or steel structure with a large surface area, paint cans are going to be your best option. Let’s look specifically at the best zinc primers that come in bulk.
ZRC Worldwide isn’t as popular as brands like Sherwin Williams, but ZRC 10002 is one of the highest reviewed zinc primer products on Amazon.
Key features include:
- Price: $59.98/quart
- Coverage: 450 square feet of coverage at 1.5 mil dry film thickness
- VOC compliant (meaning less harmful to the environment)
- Grey finish
Rust-Oleum’s zinc chromate primer is actually one of the best bang-for-your-buck purchases you can make. The product is essentially $66/galleon because it comes in a two pack. The biggest limitation with this product is it can’t ship to Arizona or Indiana due to its VOC content, which means it uses an excessive amount of solvent. The product has 4.5 stars on Amazon, but that’s with a limited sample size of 5 reviews.
- Price: $66/galleon
- Cure time: 1 hour
- Inhibits rust with alkyd formulation
- One of the best products for the price
If you want galvanic protection equivalent to a hot galvanized treatment, you’ll want a cold galvanized zinc coating. Crown 7007G offers one of the best reviewed cold galvanized zinc primers while also being reasonably priced. Note that these coatings are significantly more expensive but offer greater protection.
- Price: $172/galleon
- Product fuses to metal, sacrificing itself to prevent corrosion
- 93% pure zinc dry film
Zinc-rich primers are an excellent form of corrosion protection for facility owners and paint contractors to consider. Let’s first address how zinc primers work to ensure a complete understanding of these coating systems.
How do zinc-rich primers work?
Zinc-rich primers are part of a group of coatings known as galvanic protection systems. Galvanic systems are also know “sacrificial” systems because the coating used corrodes instead of the integral structure or component.
Zinc is more electrically active than steel and other structural materials. When the corrosion cell is formed (whenever the structure interacts with moisture, i.e., the electrolyte), the zinc primer acts as the sacrificial anode, protecting the structural material. Magnesium, aluminum and zinc can all be used as galvanic coating systems because they’re all active metals.
What are the advantages and disadvantages of zinc-rich primers?
Zinc-rich primers, and all galvanic systems, are perfect primers for steel assets in highly corrosive environments. Zinc is particularly useful in marine, tanker and underground applications, i.e., immersive environments. Any environment exposed to constant moisture will benefit from a zinc primer.
The main drawback of zinc primers is that they are consumed while providing protection. This means they have a relatively limited lifetime.
Types of zinc primers
Zinc primers come in two basic forms: inorganic and organic zinc-rich coatings.
Inorganic zinc vs. organic zinc coatings
Inorganic zinc coatings:
- Can be used without a topcoat in mild atmospheric environments
- Usually only use silicate as a binder
- Contain more zinc and provide better galvanic protection
- Require abrasive blasting or near-white blasting to be long-lasting and effective
- Are usually applied in shops via a spray
Organic zinc coatings:
- Must be top-coated to provide long-lasting protection
- Use a wide variety of binders from epoxy to alkyd
- Are easier to apply
- Are usually applied in the field via a brush or roller
Organic zinc coatings usually act as maintenance coatings for inorganic coatings due to their relative ease of application.
Zinc chromate vs. zinc phosphate
In general, zinc chromate is a more effective and robust than zinc phosphate. Zinc chromate is epoxy based, while zinc phosphate is an alkyd, which means zinc chromate is more durable when used in a primer.
While zinc chromate primers might be more durable, longer lasting, and ultimately more effective, they also come with serious risks.
Studies have found that zinc chromate is harmful and carcinogenic to humans. The New Jersey Department of Health and Senior science notes there are no safe levels of carcinogens in humans.
If you choose to use zinc chromate, make sure to have proper ventilation and use the appropriate breathing equipment. Use zinc chromate primers at your own risk.
Zinc-rich primer suppliers
Below you can find a list of supplier product data sheets for various zinc primer formulations.
This post was updated April 24th 2021.