Flex Seal Primers

Flex Seal Metal & Auto Primer Built for metal. Ready in minutes.

A fast-drying, rust-inhibiting spray primer for cars and bare or coated metal. Sandable in 5 minutes, paint-ready in 10.

Buy Now —$9.99

  • Rust-Inhibiting

    Helps protect bare & coated metal

  • Paintable

    Compatible with latex, oil, & lacquer-based paints

  • Fast Drying

    Top-coat ready in 10 minutes

  • Wide-Fan Spray

    Cover larger surface areas with an even coat

Why It Works

Protect Metal. Fight Rust. Move Fast.

Spraying Flex Seal Metal & Auto Primer onto the bare metal front fender of a truck in a garage

Handles the Heat

Resists heat up to 250°F once cured, making it ideal for parts near the engine.

Wide fan spray of Flex Seal Metal & Auto Primer laying an even gray coat across a metal garage door

Wide Coverage Straight from the Can

A wide fan spray lays down a smooth, even coat across big surfaces like garage doors. No spray gun needed.

Spraying Flex Seal Metal & Auto Primer onto a bare metal mailbox, with the flag masked off

Superior Adhesion

Provides a powerful protective coating for mailboxes, outdoor fixtures, wrought iron, & more.

Where to Use It

From Bare Metal to Finished Paint.

Pick a surface, then drag the slider to see Flex Seal Metal & Auto Primer get it ready for paint.

Car front end after priming with Flex Seal Metal & Auto Primer and painting: smooth, even finish Car front end before priming: dented, uneven hood

Use it onBare and coated body panels: fenders, hoods and doors

After photos show the surface primed, then painted. Before priming, clean the surface and remove loose rust and scale.Results vary by surface.

Gloved hand spraying a wide fan of Flex Seal Metal & Auto Primer across a bare metal panel in a garage

How It Works

Spray. Sand. Topcoat. Done.

Three steps and as little as 10 minutes between primer and paint, so your project keeps moving.

  1. Prep

    Make sure the surface is clean, dry and free of dirt, grease, oil, and loose rust or scale.

  2. Spray

    Shake can well and hold it 6–12" away from the application surface. Spray with a steady, back-and-forth motion, slightly overlapping each stroke. Once you're done, turn the can upside down and give it a quick spray to clear the nozzle to help prevent a clog.

  3. Let Dry & Finish

    Allow about 5 minutes for the product to dry before sanding. It will be ready for a top-coat of paint in about 10 minutes. Thicker coats may take longer to dry.

Flex Seal Metal and Auto Primer, gray, 15 oz aerosol can
Flex Seal Metal and Auto Primer can: rust-inhibiting protection, paint-ready in 10 minutes, wide fan spray, heat resistant up to 250°F
Spraying Metal and Auto Primer on a metal mailbox: spray, sand, topcoat, done
Before and after: a car fender primed gray with Metal and Auto Primer
Superior adhesion to metal surfaces: auto body panels, wrought iron fences, garage doors, tools and equipment
How to use: 1 prep, 2 spray, 3 sand and paint. Sandable in 5 minutes, ready for topcoat in 10
From the makers of Flex Seal: tested and proven, millions sold, satisfaction guaranteed

Flex Seal Metal & Auto Primer

15 oz · Sandable finish · Covers 18 sq ft

$9.99

Color: Gray

White, Stain Blocking Primer Gray, Metal and Auto Primer, selected

White is our Stain Blocking Primer →

15 oz Sandable finish Covers 18 sq ft

$9.99

  • Rust-inhibiting, with superior adhesion to bare and coated metal
  • Wide fan spray for a smooth, even coat
  • Sandable in 5 minutes, paint-ready in 10
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Details

Flex Seal Metal & Auto Primer is a fast-drying, rust-inhibiting aerosol primer with superior adhesion to bare and coated metal. Its wide fan spray lays down a smooth, even coat that's sandable in 5 minutes and ready for topcoat in 10. Great for large surfaces like automotive body work, wrought iron, garage doors and more.

Use on: Auto body and metal prep, bare and coated metal, wrought iron, fences and garage doors, tools, equipment and outdoor fixtures, furniture, cabinets and trim, doors, & more.

Not for: Surfaces that stay hotter than 250°F, continuous water immersion, or use as a standalone waterproofing product. On galvanized (zinc-coated) metal, test a small area first, as adhesion may vary.

Specifications
Size15 oz (425 g) aerosol
Color / finishGray, flat, sandable
Coverage18 sq ft per can
BaseNitrocellulose lacquer
Dry to touch5 minutes
SandableIn 5 minutes
Topcoat readyIn 10 minutes
TopcoatsLatex, oil-based or lacquer
SprayWide fan spray
Heat resistanceUp to 250°F (cured)
Apply between50°F and 90°F
UseInterior and exterior

Dry times at 72°F, 50% relative humidity and a 1.5 mil coat. Thicker or multiple coats take longer.

Directions
  1. Read all directions and warnings before use. Wear gloves and eye protection and work in a well-ventilated area.
  2. Surface must be clean, dry and free of dirt, grease, oil, loose rust, or scale.
  3. Shake the can well before use. Apply only when the temperature is between 50°F and 90°F.
  4. Hold the can about 6–12 inches from the surface. Spray in a steady back-and-forth motion, slightly overlapping each stroke. Keep the can moving at all times.
  5. Let dry for 5 minutes before sanding. It will be ready for a topcoat of paint in 10 minutes. Thicker applications may take longer to dry.
  6. Turn the can and spray to clear the tip before storing.
Safety & Storage

Danger: Extremely flammable. Contents under pressure. Keep away from heat, sparks and open flame. Use only in a well-ventilated area. Wear eye protection and gloves. Keep out of reach of children.

Warning: If you scrape, sand or remove old paint, you may release lead dust. Lead is toxic. For more information, visit epa.gov/lead.

WARNING: California Prop 65 Notice

FAQs

Metal & Auto Primer Questions Answered.

It depends on the surface. Use Metal & Auto Primer (gray) on cars and bare or coated metal: it's rust-inhibiting, sandable in 5 minutes and topcoat-ready in 10. Use Stain Blocking Primer (white) on walls, ceilings, wood and masonry, when you need to cover stains like water, smoke or grease so they don't bleed through your paint. Shop Stain Blocking Primer →
It's a fast-drying, rust-inhibiting spray primer made with a nitrocellulose lacquer formula. Its wide fan spray lays down a smooth, even coat with superior adhesion to bare and coated metal. It's sandable in as little as 5 minutes and ready for a topcoat in 10.
No. It's a primer, not a topcoat paint. It promotes adhesion, helps protect against rust and corrosion, and prepares bare or coated metal for a color topcoat. Apply a compatible topcoat once the primer reaches its topcoat-ready time of about 10 minutes.
Yes. It's made for auto body panels and bare metal touch-ups before you paint. Once cured, it resists heat up to 250°F, so it also works on parts near the engine. It's not meant for surfaces that stay hotter than 250°F.
Use it on bare and coated metal, auto body panels, wrought iron, fences, garage doors, mailboxes and outdoor fixtures, lawn and garden equipment, tools, furniture, cabinets, trim, doors and drywall. On galvanized (zinc-coated) metal, wood or plastic, test a small, hidden area first, since adhesion can vary. It's not for surfaces that sit in water or as a standalone waterproofing product.
Yes, after you prep it. Remove any loose rust and scale, then make sure the surface is clean and dry. From there, the rust-inhibiting formula helps protect the metal.

It's dry to the touch and sandable in 5 minutes, and ready for a topcoat in 10. Multiple coats or thick coats take longer to dry.Times at 72°F, 50% relative humidity and a 1.5 mil coat.
Latex, oil-based or lacquer paint, once the primer reaches its topcoat-ready time of about 10 minutes.
One 15 oz can covers about 18 sq ft. Coverage depends on the surface and how many coats you apply, so for larger projects, plan on more than one can.
Yes, it's made for both. Indoors: open windows and doors or use a fan so there's fresh air while you spray and while it dries, and keep it away from heat, sparks, open flame and appliances with pilot lights until the vapors clear. Outdoors: don't apply it in rain, in humidity above 85%, or when rain is expected within 24 hours. Either way, wear gloves and eye protection and apply between 50°F and 90°F.
Keep the tip clean. Before you store the can, turn it upside down and spray briefly to clear the tip so it's ready next time. Clean any wet overspray right away with paint or lacquer thinner.
Store it in a cool, well-ventilated place out of direct sunlight, ideally between 40°F and 100°F. Don't store it above 120°F, since heat can cause the can to burst.

Flex Seal Primers

Choose the Right Primer

A great paint job starts with the right prep. Compare our primers to find the right one for your project.

Flex Seal Metal and Auto Primer, gray, 15 oz can

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Metal & Auto Primer

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Best for

Cars, bare & coated metal

What it does

Inhibits rust and bonds to bare and coated metal

Ready to paint

In 10 minutes · sandable in 5 min

Temperature

Heat resistant to 250°F · apply 50–90°F

Color and size

Gray · 15 oz can

Coverage

18 sq ft per can

Use

Interior & exterior

Flex Seal Stain Blocking Primer, white, 12 oz can

Also available

Stain Blocking Primer

Shop Stain BlockingShop Now
Best for

Walls, ceilings, wood & masonry

What it does

Seals water, smoke, tannin, ink and grease stains so they don't bleed through paint

Ready to paint

In 1 hour · dry to the touch in 15–30 min

Temperature

Apply between 50°F and 90°F

Color and size

White · 12 oz can

Coverage

6–8 sq ft per can

Use

Interior & exterior