While over-application of anaerobic sealant leads to messy squeeze-out and potential contamination, using too little sealant poses a far greater risk: a guaranteed leak.

The purpose of an anaerobic flange sealant is to create a complete, form-in-place barrier by filling every microscopic void and imperfection between two mating metal surfaces. If the sealant is spread too thinly or an insufficient bead is applied, the material may not completely cover the flange face, leaving voids and direct paths for fluids to escape.

The Problem: Voids in the Seal

Applying sealant as a thin, paint-like film, or using a bead that is too small, results in two critical failures:

1. Incomplete Coverage: The sealant fails to flow into every scratch, groove, or surface irregularity when the parts are clamped. These empty spaces become leak paths, especially under operational pressure.
   
2. Insufficient Material for the Gap: Even in a precise machined joint (up to 0.25 mm), there must be enough bulk material to fill the entire volume of the gap. A thin film may not have the mass to fully displace the air and achieve the necessary cross-sectional density for a strong, reliable polymer seal.

Result: You may have a partial cure, but the voids act as wicks, drawing oil or coolant through the joint and leading to immediate or delayed failure.

The Solution: The Continuous, Controlled Bead

The fix for under-application is to use a continuous, uniform bead that is just large enough to ensure full, even coverage across the entire flange face when clamped, but not so large that it creates excess mess.

The Application Standard: The 1 mm to 2 mm Bead

The ideal application method is to lay a single, controlled bead that is roughly 1 mm to 2 mm (the size of a match head or small piece of shoestring) in diameter, encircling all bolt holes and fluid ports.

• Continuous: The bead must be unbroken.
• Encircling: Ensure a complete loop around all critical areas.
• Inboard: Keep the bead slightly inside the edge of the flange to minimize exposed squeeze-out.

When torqued, this sized bead provides enough material to flow and fill all micro-gaps within the 0.25 mm tolerance zone, ensuring 100% surface-to-surface contact.

Incure HeatGrip™ 504 for Confidence

To help ensure you achieve complete coverage without being wasteful, we recommend the Incure HeatGrip™ 504 Flexible General Purpose Gasket Sealant.

• Visual Assurance: The distinct purple color of the HeatGrip 504 makes it easy to monitor your bead size during application and visually confirm full coverage when the parts are mated. If you see a break or thin spot in the purple bead, you know exactly where to correct it before assembly.
  
• Dependable Flexibility: Its flexibility provides a forgiving seal that conforms well to the entire mating surface, effectively sealing all microscopic pathways for leaks.
  
• Strong Performance: With a maximum gap fill of 0.25 mm and resistance up to 150∘C, the HeatGrip 504 provides the robust, form-in-place seal necessary for most general-purpose applications.

Remember: A successful anaerobic seal is all about controlled precision. Use the right amount—not too much, and certainly not too little—to guarantee a void-free, leak-proof joint.