Sealing choices look small on a bill of materials and large on a warranty report. Deciding between a pre-cut gasket and a formed-in-place liquid gasket shapes tooling cost, assembly labor, inventory, and how long the joint stays leak-free in service.

Conventional Pre-Cut Gaskets

For decades, die-cut or molded gaskets from rubber, cork, fiber, or polymer sheet have been the default. They sit between two mating faces and seal under bolt compression.

Where they still make sense:

• Well-characterized materials with published chemical and temperature ratings.
• Low production volumes where manual placement is quick.
• Applications an OEM specifies by part number for warranty reasons.
• Very large flange gaps that a liquid bead cannot bridge.

Their limits:

• Tooling. Each shape needs its own die, adding upfront cost and lead time.
• Compression set. Over months under load the material loses rebound and the seal relaxes.
• Handling. Misalignment or a small tear during assembly opens a leak path.
• Inventory. Every size and shape is a separate stocked item.
• Scrap. Die-cutting wastes a meaningful fraction of the sheet.

Formed-in-Place Liquid Gaskets

A formed-in-place gasket, also called FIPG or dispense-in-place, is a liquid or paste bead applied directly to the flange that then cures into a seamless custom seal. The process suits robotic dispensing for precision and speed.

Where FIPG is strong:

• Geometry. The bead follows any contour, corner, or multi-level surface, and seals around internal partitions in one continuous pass.
• Surface conformity. The uncured material flows into machining marks and minor scratches, closing leak paths a rigid gasket bridges over.
• No compression set. The cured bead does not relax the way a compressed sheet does, and it resists vibration and thermal cycling.
• Inventory and scrap. One cartridge replaces a family of pre-cut shapes, and material is placed only where needed.
• Automation. A dispensing robot lays a repeatable bead at line speed.

What it demands:

• Cure time. Handling strength comes in minutes, but full cure can take hours before the joint sees pressure or fluid.
• Surface prep. Faces must be clean, dry, and free of oil for the bead to adhere and cure.
• Bead control. Too much material squeezes out into internal passages; too little leaves gaps. Automated dispensing makes this repeatable.
• Chemistry match. Silicone, anaerobic, and polyurethane FIPG each fit different temperature, chemical, and gap conditions.

Choosing Between Them

FIPG tends to win when flanges are irregular or hard to machine flat, when the joint sees high vibration or thermal cycling, for fluid containment such as covers and housings, for complex geometries, and for automated high-volume assembly. Pre-cut gaskets hold their place for safety-critical high-pressure joints with specific multi-layer construction, for very large gaps, when rapid repeated disassembly is routine, and when an OEM mandates a part.

Differential expansion between a cover and its housing is a common driver of seal fatigue. Our guide on how CTE mismatch causes adhesive bond failure covers the mechanism, which applies to cured sealant beads as well as adhesives.

Email Us with your flange material, operating temperature and pressure, fluid exposure, and production volume, and Incure’s team can recommend a sealing approach.

Getting FIPG Right on the Line

• Prepare the surface. Remove old sealant, oil, and oxidation. A clean face is non-negotiable for adhesion and cure.
• Set the bead. Program a continuous bead of the specified cross-section, routed inside the bolt circle and around every bolt hole.
• Control cure. Give the specified handling and full-cure times before test or fill; do not rush pressure onto a green bead.
• Torque in sequence. Follow the bolt pattern and torque spec so compression is even.
• Validate. Pressure-test prototypes under simulated service conditions, including temperature and vibration, before releasing the process.

Choosing the FIPG Chemistry

The cure mechanism is as important as the polymer:

• UV-curable FIPG fixes in seconds under a lamp, which suits high-speed lines and lets the part move immediately. It needs line of sight to the bead, so recessed grooves may need a dual-cure grade. Where UV cure is used, treat the material and lamp as one system and set the dose to the material’s specified energy; our overview of the best UV lamp for resin curing covers lamp selection.
• Moisture-cure silicone FIPG needs no equipment and tolerates shadowed grooves, but full cure takes hours and depends on ambient humidity.
• Heat-cure FIPG gives consistent, fast cure in an oven but adds a thermal step and is unsuitable for heat-sensitive housings.

Common FIPG Failure Modes

Most FIPG problems trace to process, not material: a bead routed outside the bolt circle so compression pushes it off the flange, insufficient cure before pressure test, contamination from a skipped cleaning step, or a bead cross-section too small to fill the flange gap under maximum bolt spacing. Each is caught by validating the dispense path, cure schedule, and prep sequence on production hardware before release.

Working With Incure

Incure supplies formed-in-place liquid gasket materials in UV-curable, heat-curable, and moisture-curable chemistries, along with dispensing and curing equipment and application support on material selection, surface preparation, and process integration.

Contact Our Team to discuss a sealing application and whether FIPG or a conventional gasket fits it better.

Visit www.incurelab.com for more information.