Loctite LOC18581 Rtv Silicone Gasket Maker 300 Ml

Product Description

The LOCTITE LOC18581 is a grey RTV silicone gasket maker formulated for high-performance flange sealing in demanding trade applications. Based on the 5699 formula, this product cures at room temperature to form a flexible, durable gasket that resists fluids, vibration, and thermal cycling. It ships in a 300 ml cartridge, making it compatible with standard caulking guns for controlled, consistent application on flanged joints. HVAC technicians, plumbers, and mechanical contractors rely on RTV silicone gasket makers to seal mating surfaces where a cut gasket is unavailable or insufficient. The grey color indicates a high-temp silicone chemistry suited for a broad range of sealing tasks.

This product is used across residential and commercial mechanical systems where flange-to-flange sealing is required. Common applications include sealing oil pans, valve covers, thermostats housings, pipe flanges, and mechanical equipment covers. The 300 ml cartridge format is well suited for production or repetitive repair work where a tube would run out too quickly. Trade professionals use it when reassembling equipment that requires a formed-in-place gasket rather than a pre-cut one.

Key Features

• Grey RTV silicone formulation rated for high-performance flange sealing
• 300 ml cartridge format works with standard caulking guns for controlled dispensing
• Room-temperature cure eliminates need for heat or special curing equipment
• Flexible cured bead accommodates surface irregularities and vibration
• Resistant to fluids, oils, and thermal cycling common in mechanical systems

Compatibility

Designed as a general-purpose RTV silicone gasket maker suitable for flanged joints in HVAC, plumbing, and mechanical equipment service where a flexible formed-in-place gasket seal is required.

Installation Notes

Application should be performed by a qualified tradesperson following equipment manufacturer guidelines. Always power down or shut off the system and allow all surfaces to cool before applying sealant. Clean and degrease mating surfaces thoroughly before applying a continuous bead, then assemble parts and allow adequate cure time before returning the system to service. Refer to applicable mechanical codes such as the IFGC or IPC for any code-governed piping assemblies.

Technical Specifications

• Model: 5699
• Color: Grey
• Type: High Performance Flange Sealant
• Size: 300 ml Cartridge
• Weight: 1.135 pounds
• UPC: 0079340185814

Standard Information

• Brand: LOCTITE
• Manufacturer Part Number: LOC18581