RCD #6 Mastic Duct Sealant
by RCD Corporation
Last updated Mar 29, 2026 · 2 revisions
Fiber-reinforced, UL-listed water-based mastic preferred by professional HVAC and weatherization contractors nationwide.
4.5 - Fair
Custom · $37
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Media
www.rcdmastics.com
About This Product
RCD #6 Mastic is a white, flexible, water-borne duct sealant used to permanently seal joints and seams of flexible air ducts, ductboard, sheet metal ducts, and thermal insulation. Available in 10.6 oz cartridges and 1-gallon pails, it meets all SMACNA seal classes and is the industry standard for residential duct sealing.
FSH Score Breakdown
Ease of Use 8.0
Features 5.0
Support 5.5
Value 7.5
Integrations 0.5
AI Capabilities 0.0
Customer Reviews
Features
Manual Mastic Application✓In-Place Sealing✓Pressure Testing Compatible✓Fire Rated Certification✓Flexible Substrate Adhesion✓Low VOC Formulation✓Large Scale Project Support✓
Pricing
- Model
- Custom
- Starting at
- $37
- Notes
- 1-gallon pail ~$37-45 depending on retailer (Conservation Mart $36.94, URI $44.56). Also available in 10.6 oz tube and 2-gallon pail. Available on Amazon, HVAC wholesale distributors, and specialty retailers.
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