Adhesion promotion. Dow DOWSIL PR-1204 RTV Prime Coat is a one-component, dilute solution of silane coupling agents used to increase the bonding of room-temperature and heat-curing silicones to a variety of surfaces such as glass, plastics, metals, ceramics, and masonry.
How primers work. Dow's primers, prime coats, and adhesion promoters are dilute solutions of silane coupling agents and other active ingredients whose surface-reactive components must be applied in a very thin layer for best bonding. The solvents deliver the active ingredients in a thin, uniform coating, enhance surface cleaning, and can aid penetration into the bonding surface.
Benefits. Primers can increase design flexibility, reduce total cost, or improve the reliability of electronic systems' performance, for example by enabling adhesion to lower-cost substrates or to lower-temperature processes that reduce energy use. PR-1204 is a clear, naphtha-based primer suited to bonding RTV and heat-cure silicones.
Application and storage. Apply in a very light, even coat by wiping, dipping, or spraying, wiping off excess to avoid a white, chalky overapplication; dilute two to four times for dipping or spraying. Surfaces should be cleaned and degreased first. Because it is moisture-sensitive, store below 32°C, keep tightly closed, and do not use if it turns milky. Review the Safety Data Sheet before use.
Recommended For
Promoting adhesion of RTV and heat-cure silicones
Bonding silicones to metals, glass, and ceramics
Bonding to masonry and construction materials
Surface preparation before sealing or coating
Improving reliability of bonded electronic assemblies
Product Details
Product type: One-part silane-based adhesion promoter / primer
Color: Clear
Carrier: Naphtha-based solvent solution
Application: Very thin, even coat by wiping, dipping, or spraying
Storage: Below 32°C; keep tightly closed; protect from moisture
Container size: 309 g can
Primary Industries
Electronics and PCB manufacturing
Construction and building products
Industrial bonding and sealing
Aerospace assembly
Standards and Certifications
None specified by source
FAQs
What does DOWSIL PR-1204 do?
PR-1204 is a silane-based adhesion-promoter primer that improves the bond between room-temperature and heat-curing silicones and surfaces such as glass, plastics, metals, ceramics, and masonry. Applied as a thin coat, it prepares surfaces so silicone sealants and coatings adhere more reliably in demanding applications.
How should PR-1204 be applied?
Apply it in a very light, even coat by wiping, dipping, or spraying, and wipe off any excess to avoid over-application, which can appear as a white, chalky surface. For dip or spray coating, diluting two to four times with solvent helps avoid build-up. Clean and degrease surfaces first.
How can a primer improve my design?
Primers can increase design flexibility, reduce total cost, or improve reliability, for example by enabling adhesion to lower-cost substrates or lower-temperature processes that cut energy use. By strengthening the silicone-to-substrate bond, PR-1204 helps electronic and industrial assemblies perform more reliably over their service life.
How should PR-1204 be stored?
Because it is moisture-sensitive, keep the can tightly closed with minimal headspace and store below 32°C. Do not use material that has turned milky or shows a large amount of white precipitate, as that indicates moisture contamination. Pour small amounts for immediate use into clean, dry containers.
Do I still need to clean surfaces if I use PR-1204?
Yes. Priming complements cleaning rather than replacing it. Surfaces should be cleaned and degreased with a suitable solvent, and the solvent fully evaporated before priming. For hard-to-bond, low-energy surfaces, additional treatments such as abrasion, plasma, or corona can further improve adhesion prior to primer application.
