Koelner RPS-500 is a 500 ml polyurethane foamable sealant supplied in a hose-applied format for gun use. This single-component foam fills gaps and cavities, adheres to common building substrates, and cures to a resilient closed-cell foam that provides thermal insulation, acoustic dampening, and effective wind- and water-resistant sealing for joints around windows, doors and utility penetrations.
Advantages
The foamable sealant offers easy one-component application with a dispensing gun, controlled expansion to reduce overfill, and good adhesion to masonry, concrete, wood, brick and many common building materials. Once cured, it provides thermal insulation and soundproofing benefits as well as a durable vapor-barrier surface that improves energy efficiency and reduces drafts. Its hose-applied format allows precise application in renovation and new-build work.
Suitable for
- Sealing and insulating gaps around windows and doors during installation or retrofit
- Filling cavities, voids and irregular joints in walls and between building elements
- Thermal and acoustic insulation in partitions, attic work and around service penetrations
- Bonding light-weight panels and fixing non-structural elements where foam adhesion is appropriate
When it may not be suitable
This polyurethane foam is not intended for structural load-bearing connections or as a substitute for mechanical fasteners in critical structural applications. It may not adhere well to fully glazed or very smooth non-porous surfaces without proper priming. Use caution in direct contact with certain plastics and bituminous materials that can be affected by solvent-based foams; test compatibility where necessary.
Key specifications
- Volume: 500 ml hose-applied cartridge
- Component type: single-component polyurethane foam
- Application method: gun-applied via hose
- Primary functions: sealing, thermal insulation, acoustic insulation, gap filling and bonding
- Expansion: foamable, controlled expansion suitable for medium to large joints
- Surface after cure: resilient closed-cell foam with paintable surface (after trimming)
How to use
Surface preparation: ensure surfaces are clean, dry and free of dust, grease and loose particles. Shake the cartridge if applicable and attach to the dispensing gun according to the gun and hose instructions. Application: apply foam evenly into the gap or cavity, allowing for the product's expansion; do not overfill. After application, smooth or trim excess foam after partial or full cure using a suitable cutting tool. Finished surfaces can be protected, painted or covered following full curing time indicated by the manufacturer.
What to consider before purchase
- Confirm compatibility with the surfaces you will treat (porous vs. non-porous substrates)
- Assess joint width and expected expansion to determine quantity needed
- Consider required curing time and on-site temperature/humidity conditions for best performance
- Check whether a primer is needed for certain materials or if mechanical fastening is required for structural connections
Usage recommendations
Apply at recommended ambient temperatures and use a suitable dispensing gun for even control. Protect finished foam from direct UV exposure and cover or paint cured foam where long-term outdoor exposure is expected. Wear appropriate protective equipment, and remove uncured foam from tools and surfaces with a solvent cleaner; cured foam must be trimmed mechanically.
