CHT USA Primer 7, 1 Gallon Pail, Silicone Adhesion Promoter

Description

CHT USA primer is a silicone adhesion promoter packaged here in a 1 gallon pail of slight yellow liquid, built to prepare rubber, plastic, and metal surfaces before a room-temperature-cure silicone sealant or adhesive goes down. Priming closes the gap between a bare substrate and a silicone bond line, cutting the risk of slow cure, poor wet-out, or an adhesive that peels off a difficult surface months later.

Not every substrate takes a silicone bond well on its own. Smooth plastics, certain rubber compounds, and some coated metals resist wetting from an RTV silicone bead unless something bridges the surface chemistry first. That is the job this primer does: a thin coat that gives the silicone something to key into instead of just sitting on top of the substrate.

Where CHT USA primer is used

• Gasket and seal assembly, priming rubber and plastic housings before RTV silicone application
• Metal fabrication, priming stainless, aluminum, and coated steel ahead of a silicone sealant bead
• Glass and ceramic bonding where a silicone adhesive needs help gripping a smooth, non-porous face
• Any RTV silicone or two-part elastomer job going onto a substrate known for weak primerless adhesion

How CHT USA primer performs

Applied as a thin wipe or brush coat and allowed to flash off before the silicone goes on, the primer leaves a chemical bridge that the silicone bonds into during cure instead of just sitting on the surface. That bridge turns a marginal bond on rubber or plastic into a full-strength one, and it is the difference between a sealant that holds through vibration and thermal cycling and one that lets go at a seam.

Flash time and coverage both depend on how thin the coat goes down and on ambient humidity, so test a sample area on a new substrate before committing a full production run to it. A primer applied too heavy slows cure instead of helping it.

Primer specs

• Form: Liquid
• Color: Slight yellow
• Package size: 1 gallon pail
• Chemistry: Silicone-compatible primer
• Cure partner: Room-temperature-cure (RTV) silicone sealants and adhesives

Match the primer to the silicone system and substrate on the job before ordering, and keep the pail sealed between uses since primers lose effectiveness once exposed to air repeatedly. Browse Chemical Concepts primers and accelerators, or see CHT’s full primer and specialty chemical line at cht.com.

Need Help?

Need help matching a primer to your silicone sealant and substrate combination? Call (800) 220-1966 or email [email protected].