How do I mix Carbozinc 11?

Power mix the liquid base first, then slowly pour the zinc filler through a 30-mesh screen into the premixed base with continuous agitation. Mix until free of lumps. Do not mix partial kits. Keep mixed material under mild agitation throughout application — zinc settles quickly in suspension.

Does Carbozinc 11 need a mist coat before topcoating?

Under certain conditions, yes. Applying an epoxy intermediate directly over IOZ without a mist coat can cause outgassing, resulting in bubbling and pinholes in the topcoat film. Apply a thin diluted mist coat first, allow a brief flash-off period, then apply the full wet intermediate coat.

Zinc Primer for Steel - Carbozinc 11

Q: What is the coverage rate for Carbozinc 11?

Carbozinc 11 covers 333 ft²/gal at 3.0 mils DFT and 500 ft²/gal at 2.0 mils DFT (theoretical). Recommended DFT is 2–3 mils per coat. Do not exceed 6 mils DFT — over-application limits field weldability. Allow for loss in mixing and application.

Q: What is the pot life of Carbozinc 11?

Carbozinc 11 has a pot life of 8 hours at 75°F (24°C). Pot life decreases at higher temperatures and ends when the material becomes too viscous to spray. Significantly longer than most two-component epoxies due to the inorganic silicate binder.

Q: What humidity and temperature conditions does Carbozinc 11 require?

Carbozinc 11 requires a minimum of 30% relative humidity and a maximum of 95% RH during application. The substrate temperature must remain above the dew point at all times to prevent flash rusting. For accelerated curing or where RH is below 40%, allow a 2-hour ambient cure then mist with clean potable water to keep the coating wet for at least 8 hours.

Q: Is Carbozinc 11 approved for SSPC Paint 20?

Yes — Carbozinc 11 meets SSPC Paint 20 Type I Level 1 and ASTM D520 Type II requirements for inorganic zinc-rich coatings. It also meets the Class B slip coefficient requirement (measured value 0.68) for faying surfaces in high-strength bolted steel connections per ASTM A-325.

Q: What surface preparation is required for Carbozinc 11?

Steel surfaces require SSPC-SP6 minimum blast cleaning with a 1.0–3.0 mil (25–75 micron) angular blast profile for non-immersion service. Surfaces must be clean and dry, free of dirt, dust, oil, and any contaminants that could interfere with adhesion.

Zinc Primer for Steel - Carbozinc 11

by Carboline

$292.27 - $1,523.25

$292.27

$292.27 - $1,523.25

$292.27

Carbozinc 11 by Carboline is a time-tested, solvent-based inorganic zinc silicate coating delivering industry-leading galvanic corrosion protection for steel structures in the harshest environments. For over five decades, Carbozinc 11 has been the world's most widely specified inorganic zinc primer — protecting hundreds of thousands of structures globally, including NASA's Vertical Assembly Building at Cape Canaveral. It is considered a permanent primer for steel and has never been equaled in performance or history.

This product offers several key benefits, making it a top choice for professionals seeking reliable and long-lasting corrosion protection.

Find the entire collection of Carboline Products Here >

Key Benefits:

Superior Galvanic Corrosion Protection: Carbozinc 11 protects steel cathodically through high zinc loading — 85% zinc by weight in the dry film. With over 70,000 hours of salt fog testing with no effect, it outperforms competing systems including hot dip galvanizing in long-term corrosion resistance and abrasion hardness.

Exceptional High-Temperature Resistance: Carbozinc 11 resists continuous temperatures up to 750°F (400°C) and non-continuous temperatures up to 800°F (427°C) when untopcoated. When paired with recommended high-heat topcoats, service temperatures extend to 1000°F (540°C) continuous and 1200°F (650°C) non-continuous.

Rapid Cure & Low-Temperature Application: Dry to handle in just 45 minutes at 60°F (16°C) and 50% relative humidity. Carbozinc 11 can cure at temperatures as low as 0°F (-18°C), making it suitable for year-round application in virtually any climate and ideal for fast-moving fabrication shop environments.

Meets Class B Slip Coefficient: Carbozinc 11 meets Class B slip coefficient and creep testing criteria per ASTM A-325, qualifying it for use on faying surfaces in structural steel bolted connections — a critical requirement for bridges and heavy infrastructure projects.

Proven Salt & Weather Resistance: Laboratory testing confirms no rusting, blistering, cracking, or delamination after 43,000 hours of salt spray exposure per ASTM B117. Carbozinc 11 also demonstrates excellent resistance to salting in long-term weathering exposures.

Broad Topcoat Compatibility & Compliance: Compatible with Armorlast Series inorganic silicate finishes, waterborne acrylics, epoxies, polyurethanes, and high-temperature silicones. Meets SSPC Paint 20 Type I Level 1 for zinc content, FDA requirements (gray color), and is Approved MPI #19. VOC compliant in many areas.

Common Industry Applications:

Bridges & Infrastructure: The go-to primer for structural steel in bridges, highways, and transportation infrastructure — including over 30 years of proven performance on the MODOT Bridge A-2107 with no undercutting or coating failure.
Marine & Offshore Structures: Provides exceptional galvanic protection for steel exposed to saltwater, coastal atmospheres, and offshore platforms where corrosion resistance is critical.
Industrial & Petrochemical Facilities: Ideal for tanks, vessels, piping, and structural steel in refineries, chemical plants, and manufacturing facilities, including applications requiring high-temperature resistance.
Steel Fabrication & Shop Priming: Rapid cure allows fabricated steel to be blast cleaned, primed, and ready to handle and ship within hours — making it the industry standard for high-volume fabrication shops.

CARBOZINC 11 IS A TWO-COMPONENT SYSTEM (PART A + ZINC FILLER). AVAILABLE IN 1-GALLON AND 5-GALLON KITS. DO NOT MIX PARTIAL KITS.

Product Type: Inorganic Zinc Silicate
Carbozinc 11 has a flat finish
Application: via Conventional Spray or Airless Spray (Brush for touch-up only; Roller not recommended)
Colors Available: Green (0300) and Gray (0700)
Recommended DFT: 2–3 mils (51–76 microns) — do not exceed 6.0 mils (150 microns)
Pot Life: 8 hours at 75°F (24°C)
Self-priming; topcoat not required for certain exposures

Contact our customer support today to discuss your project:
(800) 567-5358

Quantity

Area to cover (sq ft)

Application method

Coats

DFT per coat (mils)

Kit size

Color

Compatible Thinners

Thinner	Conditions	Notes
Thinner No. 33	Normal conditions	Standard thinner — most applications
Thinner No. 254	Hot / windy conditions	Slow-evaporating; prevents early skinning above 85°F
Thinner No. 21 / No. 237	Cool / low-humidity	For application below 55°F or RH <40%

⚠️ Use of unauthorized thinners may void the manufacturer's warranty. Consult Carboline TDS for exact thinning ratios.

Recommended Coating Systems

Marine / Offshore — Full 3-Coat System

Zinc Primer Carbozinc 11 2–3 mils DFT

→

Mist Coat + Intermediate Carboguard 890 Mist first, then 4–6 mils

→

Topcoat Carbothane 134 HG 2–3 mils DFT

⚠️ Mist coat required before full intermediate coat. Apply a thin mist coat of CG890, allow brief flash-off, then apply the full wet coat. Skipping the mist coat causes pinholes from IOZ outgassing.

Structural Steel — Standard Three-Coat

Zinc Primer Carbozinc 11 2–3 mils DFT

→

Intermediate Carboguard 60 4–6 mils DFT

→

Topcoat Carbothane 134 HG 2–3 mils DFT

Faying Surface (Class B Slip)

Single Coat — No Topcoat Carbozinc 11 2–3 mils · Class B certified

Frequently Purchased Together

Standard Thinner

Carboline Thinner No. 33

Primary thinner for CZ11 under normal conditions. Required for spray & brush.

$137.22

Shop Now

Intermediate Coat (Mist Coat)

Carboguard 890

Required intermediate over CZ11 in marine & heavy systems. Apply mist coat first to prevent outgassing.

UV-stable polyurethane finish coat. Final layer in CZ11 marine and structural systems.

From$292.27

Shop Now

Intermediate (Alternative)

Carboguard 893

Corrosion-resistant epoxy intermediate for use over CZ11 in 3-coat marine systems.

From$439.48

Shop Now

Product Specs — Carbozinc 11

Carbozinc 11 — Inorganic Zinc-Rich Primer (Silicate Binder) by Carboline.
One of the industry’s most trusted IOZ (inorganic zinc) primers. Provides galvanic cathodic protection for structural steel with outstanding heat resistance up to 750°F. SSPC Paint 20 Type I Level 1 certified. Class B slip coefficient for faying surfaces in bolted connections. Available in 1-gallon and 5-gallon kits.

✓ SSPC Paint 20 Type I Level 1 • ✓ ASTM D520 Type II Zinc Dust • ✓ Class B Slip Coefficient (faying surfaces) • ✓ Heat Resistant to 750°F (400°C)

✏️ Need a project quote? Request Online

📞 Questions? Call (800) 567-5358 — Mon–Fri 8AM–5PM EST

Carbozinc 11 by Carboline

Carbozinc 11 inorganic zinc-rich primer by Carboline — 1-gallon and 5-gallon kits — Carbozinc 11 — 1-Gal & 5-Gal Kits (Liquid Base + Zinc Powder)

Shipping Map — Carboline Delivery Timing

US regional warehouse map showing Carboline shipping transit zones — Typical transit times vary by destination zone. Click map to enlarge.

Shipping Time

Call (800) 567-5358 for pricing and logistics questions.

Carboline orders ship from regional warehouses nearest to your location, with full product stock maintained at each facility.

Most orders ship within 2–3 business days of order placement. Transit times shown on the map are typical but not guaranteed.

Available sizes: 1-gallon kit • 5-gallon kit

Carbozinc 11 Coverage Rates

Recommended DFT: 2–3 mils per coat. Do not exceed 6 mils DFT — over-application restricts field weldability and increases risk of mud-cracking. Minimum DFT for cathodic protection is typically 2 mils.

DFT per Coat	Coverage (Theoretical)	Typical Use
2.0 mils (50 µm)	500 ft²/gal	Minimum — atmospheric protection
3.0 mils (75 µm)	333 ft²/gal	Standard recommended — most applications
1.0 mil (25 µm)	1,000 ft²/gal	Theoretical reference — not a target DFT
>6 mils (150 µm)	—	⚠️ Not recommended — limits field weldability

Allow for application loss. Source: Carboline Carbozinc 11 TDS.

Good to Know Before You Buy

⚠️ Pro Tips & Gotchas — IOZ Primers Are Different

Power mix the base before adding zinc. Pre-mix the liquid silicate base first, then pour the zinc filler slowly through a 30-mesh screen into the premixed base with continuous agitation. Mix until completely free of lumps. Never skip sieving — dry zinc lumps cause nozzle clogs, streaks, and uneven film.
No roller application. Roller is not recommended for Carbozinc 11 or any inorganic zinc primer. Use airless spray (preferred), conventional spray, or brush for small touch-up areas only. Avoid rebrushing.
Mist coat may be required before topcoating. Under certain conditions, applying an epoxy intermediate directly over cured IOZ without a mist coat causes outgassing — bubbling and pinholes in the topcoat film. Apply a thin diluted mist coat first, flash off briefly, then apply the full wet intermediate coat.
Cure is humidity-dependent. Carbozinc 11 cures via atmospheric moisture. Minimum RH is 30%; maximum is 95%. At RH below 40%, allow a 2-hour ambient cure, then mist the coated surface with clean potable water and keep it wet for at least 8 hours to ensure complete cure.
Maximum 6 mils DFT. Over-application limits field weldability and can cause mud-cracking. Stay within the 2–3 mil recommended range for standard applications.
Not for immersion without a full topcoat system. Carbozinc 11 provides galvanic (atmospheric) cathodic protection. For submerged or immersion service, a complete epoxy intermediate and topcoat system is required over the cured IOZ.
Keep material agitated throughout application. Pot life is 8 hours at 75°F, but zinc powder settles out of suspension quickly. Keep the spray pot under continuous mild agitation and recirculate material in the spray line if application stops for more than 10 minutes.
Surface prep is non-negotiable. Steel must be blast-cleaned to SSPC-SP6 minimum with a 1.0–3.0 mil angular blast profile. Surfaces must be clean and dry. Hand tool or power tool cleaning alone will not provide sufficient anchor profile for IOZ adhesion.

Frequently Asked Questions — Carbozinc 11

What is the coverage rate for Carbozinc 11?

Carbozinc 11 covers 333 ft²/gal at 3.0 mils DFT and 500 ft²/gal at 2.0 mils DFT (theoretical, per ASTM D2697). The recommended DFT range is 2–3 mils per coat. Always allow for loss in mixing and application when estimating material quantities. Do not exceed 6 mils DFT — over-application limits field weldability.

How do I properly mix Carbozinc 11?

Power mix the liquid base thoroughly first. Then slowly pour the zinc filler through a 30-mesh screen into the premixed base while maintaining continuous agitation. Mix until completely free of lumps — sifting through the screen breaks up or catches dry zinc clumps that would otherwise clog spray tips or leave uneven coverage. Do not mix partial kits. Keep the mixed material under mild agitation throughout application, and recirculate the spray line if you stop for more than 10 minutes.

Why is a mist coat required before topcoating over Carbozinc 11?

Inorganic zinc primers are porous — the cured film off-gasses as a solvent-borne or waterborne epoxy intermediate cures over it. Applying the intermediate coat directly without a mist coat traps those gases, causing bubbling and pinholes throughout the film. Apply a thin, diluted mist coat first, allow a brief flash-off period, then apply the full wet intermediate coat. This is required under certain conditions and should be standard practice in marine and immersion systems.

Can Carbozinc 11 be applied with a roller?

No — roller application is not recommended for Carbozinc 11. Use airless spray (preferred) or conventional spray for full coverage. Brush application is permitted for touch-up of areas under one square foot only — use a medium bristle brush and avoid rebrushing.

What humidity and temperature conditions does Carbozinc 11 require?

Carbozinc 11 requires a minimum of 30% relative humidity and a maximum of 95% RH during application. The substrate temperature must be above the dew point at all times — condensation causes flash rusting on blasted steel and prevents proper adhesion. For accelerated curing or where RH is below 40%, allow a 2-hour ambient cure, then mist the coating with clean potable water and keep it wet for a minimum of 8 hours. Cure is considered complete when the film reaches a 2H pencil hardness (ASTM D3363) or a rating of 4 per ASTM D4752.

Is Carbozinc 11 approved for SSPC Paint 20?

Yes — Carbozinc 11 meets SSPC Paint 20 Type I Level 1 and ASTM D520 Type II requirements for inorganic zinc-rich coatings. It also meets the Class B slip coefficient requirement (measured value: 0.68) for faying surfaces in high-strength bolted structural steel connections per ASTM A-325.

What is the pot life of Carbozinc 11?

Carbozinc 11 has a pot life of 8 hours at 75°F (24°C) — longer than most two-component epoxies because of its inorganic silicate binder chemistry. Pot life decreases at higher temperatures; the material has reached the end of its pot life when it becomes too viscous to spray. Even within the pot life window, keep the mixed material continuously agitated to prevent zinc from settling out of suspension.

What surface preparation does Carbozinc 11 require?

Steel surfaces require SSPC-SP6 blast cleaning minimum with a 1.0–3.0 mil (25–75 micron) angular blast profile for non-immersion service. Surfaces must be clean and dry, free of dirt, dust, oil, mill scale, and any contamination that could compromise adhesion. When Carbozinc 11 is used under intumescent fireproofing, defer to the surface preparation requirements in that product’s data sheet. Hand tool or power tool cleaning alone is not acceptable.

Can Carbozinc 11 be used as a standalone coating without a topcoat?

Carbozinc 11 is self-priming and does not require a topcoat for certain atmospheric exposures. However, for immersion, buried, or severely corrosive service environments, a complete intermediate and topcoat system over the cured IOZ is required. Carbozinc 11 is not recommended for immersion service without a topcoat. Consult Carboline Technical Service for system selection specific to your exposure conditions.