Frequently Asked Questions
What is the best sealant for an RV rubber roof? +
For EPDM or TPO rubber roofs, Dicor Self-Leveling Lap Sealant is the industry standard and our top recommendation. It's specifically formulated for rubber membranes, self-levels for easy application, and provides excellent UV resistance. Never use standard silicone on RV roofs as it won't adhere properly to the membrane material and can peel off while driving.
How do I stop a boat leak underwater? +
For emergency underwater repairs, use a toilet wax ring to plug cracks instantly—it sticks even when wet and provides a temporary seal. For broken thru-hull fittings, hammer conical soft wood plugs into the opening. Underwater epoxy putty can also provide temporary sealing for hull cracks. Remember these are emergency measures only—schedule proper repairs immediately and never rely on temporary fixes for extended periods.
Is 3M 5200 sealant removable? +
No, 3M 5200 is a permanent adhesive that's extremely difficult to remove without damaging gelcoat or fiberglass. It's designed for structural bonding like hull-to-deck joints where you never want the bond to break. For deck hardware you may need to service later, use 3M 4200 or butyl tape instead—they provide strong sealing but allow for future removal without destruction. Only use 5200 for truly permanent installations.
How often should I check my RV seals? +
Inspect your RV roof and window seals every 3 months at minimum, and definitely before and after winter storage. UV damage can cause lap sealant to crack very quickly, especially in hot, sunny climates. A quarterly inspection allows you to catch problems early before water intrusion causes expensive interior damage or delamination. Clean and reseal your roof at least annually, more frequently in harsh environments.
What causes deck hardware to leak on boats? +
Deck hardware leaks primarily from bedding compound failure. UV exposure, thermal cycling, and mechanical stress cause sealants to crack and lose adhesion over time. Additionally, if hardware was originally installed without proper backing plates, hull flexing creates stress that breaks sealant bonds. Some boats have balsa core in the deck that absorbs water through improperly sealed fastener holes, leading to rot that loosens the hardware mounting. Proper rebedding with quality materials like butyl tape prevents these issues.
Should I use silicone for marine applications? +
Generally no—silicone is rarely the right choice for marine applications. While it's waterproof and flexible, it has poor adhesion to many marine substrates and makes future repairs extremely difficult because nothing sticks to cured silicone. For boats, use marine-grade polyurethane (like Sikaflex 291 or 3M 4200) or polysulfide sealants. For RV roofs, use lap sealants specifically formulated for rubber membranes. Silicone should only be used for very specific applications where recommended by manufacturers.
How long do sealants last before needing replacement? +
Sealant lifespan varies significantly based on exposure and application. RV roof lap sealant typically needs reapplication every 1-3 years depending on climate—UV exposure is the primary degradation factor. Marine polyurethane sealants like Sikaflex or 3M products generally last 5-10 years in above-waterline applications if properly applied. Butyl tape never fully hardens and can last 15+ years. Regular inspection is more important than following rigid schedules—replace sealants when you observe cracking, pulling away, or loss of flexibility regardless of age.