Flex Paste Waterproof Paintable Putty Sealant — Clear Half-Quart, Flexible, UV-Resistant Repair Paste

Flex Paste is a professional-grade, waterproof, paintable rubberized putty that fills gaps, seals cracks and blocks out air and water for interior and exterior repairs.

Designed as a thick, clingy paste, Flex Paste bonds to many building materials — drywall, concrete, EPDM, metal, and more — and cures into a flexible, watertight barrier. The new stay-fresh container minimizes wasted product by keeping the paste airtight between uses. This clear half-quart size is ideal for homeowners, handymen and pros who need an easy-to-apply sealant that can be painted after curing and resists UV exposure.

How does Flex Paste stop leaks and drafts?

Flex Paste penetrates and adheres deeply to surfaces, creating a continuous rubberized membrane that blocks the movement of air and water. Because it remains flexible after curing, it moves with the substrate instead of cracking, maintaining the seal over time.

• Creates a watertight, flexible layer that adheres to many surfaces
• Clings to vertical and overhead areas without sagging
• Blocks air infiltration and seals out moisture pathways
• UV resistant finish helps protect exposed repairs

Can I use Flex Paste on different materials like roofs, drywall, or RV exteriors?

Yes. Flex Paste is formulated to work on a wide range of common building substrates. Its thick consistency makes it especially useful for filling large voids and bridging uneven surfaces on roofs, RVs, walls and concrete.

• Suitable for EPDM roof patches, RV seams and flashing repairs
• Effective on drywall seams, corner gaps and small holes
• Bonds to concrete, metal, wood and many plastics with proper surface prep
• Can be applied underwater for certain marine or below-grade fixes

How do I apply, finish and paint Flex Paste?

Application is straightforward: surface should be clean and free of loose material, then apply with a putty knife or trowel and smooth to the desired profile. Once fully cured, Flex Paste accepts most paints, allowing a seamless repair that blends with surrounding finishes.

• Press paste firmly into gaps; tool smooth for desired look
• Cures into a rubberized, sandable surface ready for paint
• Follow manufacturer cure times before painting for best adhesion
• New stay-fresh container preserves unused product between jobs

Is Flex Paste durable enough for outdoor and submerged repairs?

Flex Paste is engineered to endure outdoor exposure and can even be applied and cured underwater, making it suitable for tough conditions. Its cured film resists UV degradation and helps protect against rust or corrosion on metal substrates.

• Can be used underwater and dries while submerged
• UV resistant for extended outdoor life
• Helps prevent rust and corrosion when used on metal surfaces
• Flexible finish moves with temperature and substrate shifts

Who is this for: Flex Paste in the clear half-quart size is ideal for homeowners tackling patchwork, contractors needing a small-batch professional sealant, and RV or boat owners who require a versatile, paintable repair compound. Choose this for projects that demand a thick, non-sagging paste that cures to a durable, watertight rubberized barrier and can be stored fresh between uses for future touch-ups.