The Difference Between Epoxy Sealant & RTV Sealant
The main difference between epoxy sealant and RTV (Room Temperature Vulcanizing) sealant lies in their chemical composition, curing mechanisms, and typical applications. Here’s a side-by-side comparison to help you understand the distinctions:
1. Composition & Chemistry
| Feature | Epoxy Sealant | RTV Sealant |
| Base Material | Thermosetting polymers
(epoxy resins + hardeners) |
Silicone-based |
| Curing Mechanism | Chemical reaction between resin
and Cures with exposure to moisture in the air hardener |
(moisture-cured) |
2. Curing Characteristics
| Feature | Epoxy | RTV |
| Curing Time | Varies (minutes to hours) depending on
formulation |
Generally cures in 24 hours at room
temperature |
| Cure Type | Exothermic (generates heat) | No heat generated |
| Shrinkage | Minimal | Minimal |
3. Properties After Curing
| Property | Epoxy | RTV Silicone |
| Hardness | Very hard and rigid | Flexible, rubber-like |
| Temperature
Resistance |
Up to ~150–200°C | Up to ~250–300°C
(some up to 315°C) |
| Chemical Resistance | Excellent (solvents, oils, etc.)
Good, especially against water and mild |
chemicals |
| Electrical Insulation
|
Excellent | Excellent |
4. Applications
| Use Case | Epoxy | RTV Silicone |
| Bonding & Structural Repair | Yes (strong, rigid bonds) | No (not structural) |
| Sealing Gaps, Joints | Yes | Yes |
| Electronic Potting/Encapsulation | Common | Also common, especially for flexibility |
| Automotive/Engine Gaskets
|
Rare | Very common (RTV gasket makers) |
| Waterproofing
|
Good | Excellent, especially in flexible joints |
5. Removal & Rework
| Feature | Epoxy | RTV |
| Removability | Difficult (rigid, adheres strongly) | Easier (rubbery, peels off) |
6. Summary Recommendations
| Scenario | Recommended Sealant |
| Bonding rigid components | Epoxy |
| Sealing flexible joints or engine gaskets | RTV Silicone |
| Electronics potting needing rigidity | Epoxy |
| Electronics needing vibration resistance | RTV Silicone |
| Heat resistance above 200°C | RTV Silicone (high-temp grade) |
| Water or weather sealing | RTV Silicone |
Recommend
Products
Online Service
Your satisfaction is our success.
For product inquiries or questions, pls feel free to contact us.
Leave a message below, and we’ll get back to you promptly.
Contact Us