Unlike standard construction caulks, Pro Flex RV is engineered specifically for the stresses that come with RV ownership: seasonal storage, highway vibration, temperature cycling from below zero to summer rooftop heat, and exposure to rain, UV, and road chemicals. Its 430% elongation rating means the sealant stretches and compresses with your rig's panels and joints rather than cracking and pulling away — keeping your seal intact for seasons to come.
One of its standout advantages is the ability to bond on surfaces that would reject ordinary sealants: damp from dew or rain, slightly oily metal surfaces, and even frozen substrates. No primer is required on most RV materials, which means faster application in the field.
Pro Flex RV is the go-to sealant for virtually every exterior joint and seam on a recreational vehicle. Ideal applications include:
Aluminum | Glass | Fiberglass | Steel | Coated Steel (Kynar 500® finishes) | Wood | Vinyl No primer required on most surfaces. A test application is recommended if adhesion to a specific substrate is uncertain.
EPDM or TPO roofing membranes (use Geocel Advanced RV EPDM Sealant instead) • Extruded polystyrene / Styrofoam insulation • Acrylic skylight glazing • Traffic-bearing surfaces • Food-contact or potable water applications
Per 10 oz. cartridge:
The GC28900X part number designates Geocel's updated formula that eliminates perchloroethylene (PERC). U.S. federal regulations phase out PERC-containing sealants beginning in late 2026. Buying the "X" formula now means you're purchasing a product that remains fully compliant and available well beyond those deadlines — and one that's available in all 50 states, including California (clear only).
White – GC28901X Black – GC28903X Almond – GC28909X Bright White – GC28927X
Can I use this on my rubber (EPDM) roof? No — Pro Flex RV Flexible Sealant is not compatible with EPDM or TPO roofing membranes. For rubber roofs, use Geocel Advanced RV EPDM Sealant, which is specifically formulated for those materials.
What's the difference between GC28900 and GC28900X? The "X" suffix indicates the new non-perchloroethylene formula. Geocel rolled out these updated part numbers beginning in late 2025 to comply with U.S. federal regulations phasing out PERC in sealants. The performance characteristics are equivalent — the change is in the solvent chemistry to meet new environmental standards.
Do I need to remove the old sealant before applying? Not necessarily. One of the advantages of Pro Flex RV is that it is resealable — it can be applied directly over existing Pro Flex RV sealant. If the original sealant is severely cracked, lifted, or contaminated, removal and a fresh application will produce a better long-term result.
How long before it can get rained on? The sealant can be exposed to weather conditions immediately after application — that's one of its key design advantages for field use.
Will "clear" look truly clear once cured? Clear Pro Flex RV dries slightly translucent rather than completely invisible, which is typical of polymer sealants. It will not be noticed from a distance and is far less visible than white or almond options on tinted windows, dark trim, or anywhere a colored bead would stand out.
Is this product available in California? Yes — the clear version (GC28900X / GC28928) is exempt from SCAQMD county VOC restrictions that prevent sale of the colored versions in California. It can be sold and used in all 50 states.
What do I need to apply it? A standard 10 oz. caulk gun is all that's required — no special applicator needed. The non-stringing formulation makes it easy to lay a clean bead and tool smooth.